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  • 1. Abrahamsson, Niclas
    et al.
    Borjesson, Joey Lau
    Sundbom, Magnus
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Karlsson, F. Anders
    Eriksson, Jan W.
    Gastric Bypass Reduces Symptoms and Hormonal Responses in Hypoglycemia2016In: Diabetes, ISSN 0012-1797, E-ISSN 1939-327X, Vol. 65, no 9, p. 2667-2675Article in journal (Refereed)
    Abstract [en]

    Gastric bypass (GBP) surgery, one of the most common bariatric procedures, induces weight loss and metabolic effects. The mechanisms are not fully understood, but reduced food intake and effects on gastrointestinal hormones are thought to contribute. We recently observed that GBP patients have lowered glucose levels and frequent asymptomatic hypoglycemic episodes. Here, we subjected patients before and after undergoing GBP surgery to hypoglycemia and examined symptoms and hormonal and autonomic nerve responses. Twelve obese patients without diabetes (8 women, mean age 43.1 years [SD 10.8] and BMI 40.6 kg/m(2) [SD 3.1]) were examined before and 23 weeks (range 19-25) after GBP surgery with hyperinsulinemic-hypoglycemic clamp (stepwise to plasma glucose 2.7 mmol/L). The mean change in Edinburgh Hypoglycemia Score during clamp was attenuated from 10.7 (6.4) before surgery to 5.2 (4.9) after surgery. There were also marked postsurgery reductions in levels of glucagon, cortisol, and catecholamine and the sympathetic nerve responses to hypoglycemia. In addition, growth hormone displayed a delayed response but to a higher peak level. Levels of glucagon-like peptide 1 and gastric inhibitory polypeptide rose during hypoglycemia but rose less postsurgery compared with presurgery. Thus, GBP surgery causes a resetting of glucose homeostasis, which reduces symptoms and neurohormonal responses to hypoglycemia. Further studies should address the underlying mechanisms as well as their impact on the overall metabolic effects of GBP surgery.

  • 2.
    Alenius Dahlqvist, Jenny
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Hörnsten, Rolf
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Rydberg, Annika
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Handheld ECG in analysis of arrhythmia and heart rate variability in children with Fontan circulation2014In: Journal of Electrocardiology, ISSN 0022-0736, E-ISSN 1532-8430, Vol. 47, no 3, p. 374-382Article in journal (Refereed)
    Abstract [en]

    Background: Our aim was to evaluate the intermittent use of a handheld ECG system for detecting silent arrhythmias and cardiac autonomic dysfunction in children with univentricular hearts. Methods: Twenty-seven patients performed intermittent ECG recordings with handheld devices during a 14-day period. A manual arrhythmia analysis was performed. We analyzed heart rate variability (HRV) using scatter plots of all interbeat intervals (Poincare plots) from the total observation period. Reference values of HRV indices were determined from Holter-ECGs in 41 healthy children. Results: One asymptomatic patient had frequent ventricular extra systoles. Another patient had episodes with supraventricular tachycardia (with concomitant palpitations). Seven patients showed reduced HRV. Conclusions: Asymptomatic arrhythmia was detected in one patient. The proposed method for pooling of intermittent recordings from handheld or similar devices may be used for detection of arrhythmias as well as for cardiac autonomic dysfunction.

  • 3.
    Alenius Dahlqvist, Jenny
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Hörnsten, Rolf
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Strömvall-Larsson, Eva
    Division of Cardiology, Department of Paediatrics, Sahlgrenska University Hospital/Queen Silvia Children’s Hospital, Göteborg University, Göteborg, Sweden.
    Berggren, Håkan
    Division of Cardiothoracic Surgery, Department of Paediatrics, Sahlgrenska University Hospital/Queen Silvia Children’s Hospital, Göteborg University, Göteborg, Sweden.
    Hanseus, Katarina
    Department of Paediatrics, Children’s Hospital, Lund University Hospital, Lund, Sweden.
    Johansson, Sune
    Paediatric Cardiac Surgical Unit, Children’s Hospital, Lund University Hospital, Lund, Sweden.
    Rydberg, Annika
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Heart rate variability in children with fontan circulation: lateral tunnel and extracardiac conduit2012In: Pediatric Cardiology, ISSN 0172-0643, E-ISSN 1432-1971, Vol. 33, no 2, p. 307-315Article in journal (Refereed)
    Abstract [en]

    The technique in Fontan surgery has developed from the lateral tunnel (LT) toward the extracardiac conduit (EC) used to reduce long-term complications such as atrial arrhythmia and sinus node dysfunction. Heart rate variability (HRV) examines cardiac nervous activity controlling the sinus node. This study aimed to investigate HRV in a cohort of children with univentricular hearts, focusing on the relation between HRV and surgical procedure. For 112 children with Fontan circulation, HRV was analyzed using power spectral analysis. Spectral power was determined in three regions: very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) regions. Patients were compared with 66 healthy controls subject. Patients with LT were compared with patients who had EC. The children with Fontan circulation showed a significantly reduced HRV including total power (P < 0.0001), VLF (P < 0.0001), LF (P < 0.0001), and HF (P = 0.001) compared with the control subjects. The LT and EC patients did not differ significantly. Reduced HRV was found in both the LT and EC patients. In terms of HRV reduction, EC was not superior to LT.

  • 4.
    Alenius Dahlqvist, Jenny
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences.
    Sunnegårdh, Jan
    Department of Cardiology, The Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Institute of Clinical Sciences, Gothenburg University, Gothenburg, Sweden.
    Hanséus, Katarina
    Department of Clinical Sciences Lund, Children Heart Center, Skåne University Hospital, Lund University, Lund, Sweden.
    Strömvall Larsson, Eva
    Department of Cardiology, The Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Institute of Clinical Sciences, Gothenburg University, Gothenburg, Sweden.
    Nygren, Anders
    Department of Cardiology, The Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Institute of Clinical Sciences, Gothenburg University, Gothenburg, Sweden.
    Dalén, Magnus
    Department of Molecular Medicine and Surgery, Department of Cardiac Surgery, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
    Berggren, Håkan
    Department of Pediatric Cardiac Surgery, Children's Heart Center, The Queen Silvia Children's Hospital, Gothenburg , Sweden.
    Johansson Ramgren, Jens
    Department of Pediatric Cardiac Surgery, Children´s Heart Center, Skånes University Hospital Lund, Sweden.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Rydberg, Annika
    Umeå University, Faculty of Medicine, Department of Clinical Sciences.
    Pacemaker treatment after Fontan surgery: a Swedish national study2019In: Congenital Heart Disease, ISSN 1747-079X, E-ISSN 1747-0803Article in journal (Other academic)
    Abstract [en]

    Objective: Fontan surgery is performed in children with univentricular heart defects. Previous data regarding permanent pacemaker implantation frequency and indications in Fontan patients are limited and conflicting. We examined the prevalence of and risk factors for pacemaker treatment in a consecutive national cohort of patients after Fontan surgery in Sweden.

    Methods: We retrospectively reviewed all Swedish patients who underwent Fontan surgery from 1982 to 2017 (n = 599).

    Results: After a mean follow‐up of 12.2 years, 13% (78/599) of the patients with Fontan circulation had received pacemakers. Patients operated with the extracardiac conduit (EC) type of total cavopulmonary connection had a significantly lower prevalence of pacemaker implantation (6%) than patients with lateral tunnel (LT; 17%). Mortality did not differ between patients with (8%) and without pacemaker (5%). The most common pacemaker indication was sinus node dysfunction (SND) (64%). Pacemaker implantation due to SND was less common among patients with EC. Pacemaker implantation was significantly more common in patients with mitral atresia (MA; 44%), double outlet right ventricle (DORV; 24%) and double inlet left ventricle (DILV; 20%). In contrast, patients with pulmonary atresia with intact ventricular septum and hypoplastic left heart syndrome were significantly less likely to receive a pacemaker (3% and 6%, respectively).

    Conclusions: Thirteen percent of Fontan patients received a permanent pacemaker, most frequently due to SND. EC was associated with a significantly lower prevalence of pacemaker than LT. Permanent pacemaker was more common in patients with MA, DORV, and DILV.

  • 5.
    Alenius Dahlqvist, Jenny
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Hanseus, Katarina
    Stromvall-Larsson, Eva
    Nygren, Anders
    Eliasson, Håkan
    Rydberg, Annika
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Sinus node dysfunction in patients with Fontan circulation: could heart rate variability be a predictor for pacemaker implantation?2019In: Pediatric Cardiology, ISSN 0172-0643, E-ISSN 1432-1971, Vol. 40, no 4, p. 685-693Article in journal (Refereed)
    Abstract [en]

    Sinus node dysfunction (SND) causes significant morbidity in patients after Fontan surgery. Heart rate variability (HRV) reflects the autonomic regulation of the heart, and changes in HRV have been associated with SND in adults. We aimed to study whether changes in HRV could be detected in 24-h electrocardiographic (ECG) recordings in Fontan patients with SND. We compared HRV results from two patient groups; patients with Fontan circulation who later required a pacemaker due to severe SND (n = 12) and patients with Fontan circulation and SND, without indication for pacemaker treatment (n = 11), with two control groups; patients with Fontan circulation without SND (n = 90) and healthy controls (n = 66). The Poincare plot index SD2 (representing changes in heart rate over 24-h) and the very low-frequency (VLF) HRV component were significantly higher in both SND groups, both compared with healthy controls and patients with Fontan circulation without SND. In SND patients with pacemakers, SD2 and VLF were slightly reduced compared to SND patients without pacemaker (p = 0.06). In conclusion, in Fontan patients with SND the HRV is significantly higher compared to healthy controls and Fontan patients without SND. However, in patients with severe SND requiring pacemaker, SD2 and VLF tended to be lower than in patients with SND without pacemaker, which could indicate a reduced diurnal HRV in addition to the severe bradycardia. This is a small study, but our results indicate that HRV analysis might be a useful method in the follow-up of Fontan patients regarding development of SND.

  • 6.
    Alenius Dahlqvist, Jenny
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Hanséus, Katarina
    Department of Clinical Sciences Lund, Children Heart Centre, Skåne University Hospital, Lund University, Lund, Sweden.
    Strömvall Larsson, Eva
    Department of Cardiology, The Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Institute of Clinical Sciences, Gothenburg University, Gothenburg, Sweden.
    Johansson Ramgren, Jens
    Department of Pediatric Cardiac Surgery, Children´s Heart Center, Skånes University Hospital Lund, Sweden.
    Berggren, Håkan
    Department of Pediatric Cardiac Surgery, Children's Heart Center, The Queen Silvia Children's Hospital, Gothenburg, Sweden.
    Rydberg, Annika
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Changes in heart rate variability during surgical stages to completed Fontan circulationManuscript (preprint) (Other academic)
    Abstract [en]

    Objectives: In patients with Fontan circulation, arrhythmia is a serious complication contributing to morbidity and mortality. Arrhythmia is related to heart rate variability (HRV), which reflects autonomic nervous regulation of the heart. Our hypothesis was that autonomic nervous ganglia, located at the junction of the superior vena cava’s entrance to the heart, may be affected during the bidirectional Glenn procedure (BDG), resulting in reduced HRV.

    Methods: 24-hour Holter ECG recordings were obtained before BDG (n=47), after BDG (n=47) and after total cavopulmonary connection (TCPC) (n=45) in patients, and in 38 healthy controls. HRV was analysed by spectral and Poincaré methods. Age-related z-scores were calculated and compared using linear mixed effects modeling.

    Results: HRV-parameters (Ptot, PVLF, PLF, PHF, PLF/PHF, SD2, and SD1/SD2) were significantly lower in patients before BDG when compared to healthy controls. The RR interval and SD2 were significantly increased in patients post  BDG compared to pre BDG. Compared to healthy controls; patients operated with BDG had significantly longer RR intervals and reduced Ptot and PLF. Patients post TCPC showed longer RR intervals, Ptot, PVLF, PLF, and PHF,  SD1, and SD1/SD2 compared with healthy controls. In patients post TCPC; Ptot, PVLF, PLF, PHF, PLF/PHF, SD2, and SD1/SD2 were decreased compared to pre TCPC.

    Conclusions: Heart rate was reduced after BDG procedure, and further reductions of HRV were seen post-TCPC. Our results indicate that autonomic regulation of cardiac rhythm is affected both after BDG and again after TCPC. This may be reflected as, and contribute to, postoperative arrhythmic events.

  • 7.
    Alenius Dahlqvist, Jenny
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Hanséus, Katarina
    Department of Clinical Sciences Lund, Children Heart Centre, Skåne University Hospital, Lund University, Lund, Sweden.
    Strömvall Larsson, Eva
    Department of Cardiology, The Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Institute of Clinical Sciences, Gothenburg University, Gothenburg, Sweden.
    Nygren, Anders
    Department of Cardiology, The Queen Silvia Children's Hospital, Sahlgrenska University Hospital, Institute of Clinical Sciences, Gothenburg University, Gothenburg, Sweden.
    Eliasson, Håkan
    Department of Women's and Children's Health, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
    Rydberg, Annika
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Sinus node dysfunction in patients with Fontan circulation: could heart rate variability be a predictor for pacemaker implantation?Manuscript (preprint) (Other academic)
  • 8. Almby, Kristina E.
    et al.
    Abrahamsson, Niclas
    Lundqvist, Martin H.
    Hammara, Ulf
    Thombare, Ketan
    Panagiotou, Amalia
    Karisson, F. Anders
    Sundbom, Magnus
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Eriksson, Jan W.
    Effects of GLP-1 on counter-regulatory responses during hypoglycemia after GBP surgery2019In: European Journal of Endocrinology, ISSN 0804-4643, E-ISSN 1479-683X, Vol. 181, no 2, p. 161-171Article in journal (Refereed)
    Abstract [en]

    Objectives: The aim of the study was to explore the role of GLP-1 receptor activation on the counter-regulation and symptoms of hypoglycemia in subjects who have undergone gastric bypass surgery (GBP).

    Design: Experimental hyperinsulinemic–hypoglycemic clamp study.

    Methods: Twelve post-GBP subjects participated in a randomized cross-over study with two hyperinsulinemic, hypoglycemic clamps (glucose nadir 2.7 mmol/L) performed on separate days with concomitant infusions of the GLP-1 analog exenatide or with saline, respectively. Continuous measurements of metabolites and counter-regulatory hormones as well as assessments of heart rate variability and symptoms of hypoglycemia were performed throughout the clamps.

    Results: No effect of GLP-1 receptor activation on counter-regulatory hormones (glucagon, catecholamines, cortisol, GH) or glucose infusion rate was seen, but we found indications of a downregulation of the sympathetic relative to the parasympathetic nerve activity, as reflected in heart rate variability. No significant differences in symptom of hypoglycemia were observed.

    Conclusions/interpretation: Short-term exposure to a GLP-1 receptor agonist does not seem to impact the counter-regulatory hormonal and metabolic responses in post-GBP subjects during hypoglycemic conditions, suggesting that the improvement in symptomatic hypoglycemia post-GBP seen following treatment with GLP-1 receptor agonists may be mediated by mechanism not directly involved in counter-regulation.

  • 9.
    Andersson, Jonas
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Ryberg, Mats
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Sjöström, Lars-Göran
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Wiklund, Urban
    Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Karpe, Fredrik
    NIHR Oxford Biomedical Research Centre, Churchill Hospital, Oxford, UK..
    Lindahl, Bernt
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Olsson, Tommy
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Long term effects of a diet intervention on adipose tissue blood flow, heart rate variability and endothelial function: a randomized controlled trialManuscript (preprint) (Other academic)
  • 10.
    Andersson, Jonas
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Sjöström, Lars-Göran
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Hultin, Magnus
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Karpe, Fredrik
    Olsson, Tommy
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Dysregulation of subcutaneous adipose tissue blood flow in overweight postmenopausal women2010In: Menopause: The Journal of the North American Menopause, ISSN 1072-3714, E-ISSN 1530-0374, Vol. 17, no 2, p. 365-371Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: A putative link between abdominal obesity and metabolic-vascular complications after menopause may be due to a decreased adipose tissue blood flow (ATBF). The present work aimed to analyze possible changes in ATBF with being overweight and menopausal and its putative link to endothelial dysfunction and autonomic nervous system balance.

    METHODS: Forty-three healthy women were classified into four groups according to weight and menopause status. The ATBF was measured by xenon washout while fasting and after oral glucose intake. The nitric oxide synthase inhibitor asymmetric dimethylarginine was used as a marker of endothelial function and heart rate variability-estimated autonomic nervous system activity.

    RESULTS: Fasting ATBF was decreased in both overweight groups (P = 0.044 and P = 0.048) versus normal-weight premenopausal women. Normal-weight and overweight postmenopausal women exhibited lower maximum ATBF compared with normal-weight premenopausal women (P = 0.015 and P = 0.001, respectively), and overweight postmenopausal women exhibited lower maximum ATBF compared with normal-weight postmenopausal women (P = 0.003). A negative correlation was found between fasting ATBF and asymmetric dimethylarginine (P = 0.015), whereas maximum ATBF was negatively associated with sympathetic-parasympathetic nervous system balance (ratio of the power of the low frequency to the power of the high frequency; P = 0.002).

    CONCLUSIONS: Loss of ATBF flexibility in overweight postmenopausal women may contribute to the metabolic dysfunction seen in this group of women.

  • 11.
    Andersson, Kennet
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Suhr, Ole B.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Faes, Luca
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Directed coherence analysis in patients with severe autonomic dysfunction2014In: 2014 8th conference of the European Study Group on Cardiovascular Oscillations (ESGCO), IEEE conference proceedings, 2014, p. 167-168Conference paper (Refereed)
    Abstract [en]

    Many different approaches have been applied to analyse the coupling between cardiovascular signals. This study evaluated the use of directed coherence, based on multivariate autoregressive modelling, for analysis of cardiovascular signals in patients with transthyretin amyloidosis, a rare disease where severe autonomic dysfunction is common.

  • 12.
    Andersson, Nina
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Malm, Jan
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Neurology.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Eklund, Anders
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Adaptive method for assessment of cerebrospinal fluid outflow conductance.2007In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 45, no 4, p. 337-343Article in journal (Refereed)
    Abstract [en]

    Outflow conductance (C out) is important for predicting shunt responsiveness in patients with suspected idiopathic adult hydrocephalus syndrome (IAHS). C out is determined by performing an infusion test into the cerebrospinal fluid system, and the reliability of the test is dependent on the measurement time. The objective of this study was to develop an adaptive signal analysis method to reduce the investigation time, by taking the individual intracranial pressure variations of the patient into consideration. The method was evaluated on 28 patients with suspected IAHS. The results from full time investigations (60 min) were compared to the results of the new algorithm. Applying the new adaptive method resulted in a reduction of mean investigation time by 14.3 ± 5.9 min (mean ± SD), p < 0.01. The reduction of reliability in the C out estimation was found clinically negligible. We thus recommend this adaptive method to be used when performing constant pressure infusion tests.

  • 13.
    Björ, Bodil
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Burström, Lage
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Karlsson, Marcus
    Nilsson, Tohr
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Näslund, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Acute effects on heart rate variability when exposed to hand transmitted vibration and noise.2007In: International Archives of Occupational and Environmental Health, ISSN 0340-0131, E-ISSN 1432-1246, Vol. 81, no 2, p. 193-199Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: This study investigates possible acute effects on heart rate variability (HRV) when people are exposed to hand transmitted vibration and noise individually and simultaneously. METHODS: Ten male and 10 female subjects were recruited by advertisement. Subjects completed a questionnaire concerning their work environment, general health, medication, hearing, and physical activity level. The test started with the subject resting for 15 min while sitting down. After resting, they were exposed to one of four exposure conditions: (1) only vibration; (2) only noise; (3) both noise and vibration; or (4) a control condition of exposure to the static load only. All four exposures lasted 15 min and the resting time between the exposures was 30 min. A continuous electrocardiogram (ECG) signal was recorded and the following HRV parameters were calculated: total spectral power (P(TOT)); the spectral power of the very low frequency component (P(VLF)); the low frequency component (P(LF)); the high frequency component (P(HF)); and the ratio LF/HF. RESULTS: Exposure to only vibration resulted in a lower P(TOT) compared to static load, whereas exposure to only noise resulted in a higher P(TOT). The mean values of P(TOT), P(VLF), P(LF), and P(HF) were lowest during exposure to vibration and simultaneous exposure to vibration and noise. CONCLUSIONS: Exposure to vibration and/or noise acutely affects HRV compared to standing without these exposures. Being exposed to vibration only and being exposed to noise only seem to generate opposite effects. Compared to no exposure, P(TOT) was reduced during vibration exposure and increased during noise exposure.

  • 14.
    Boles, Usama
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology. Cardiology Department, Letterkenny University Hospital, Letterkenny, Co. Donegal, Ireland.
    Johansson, Anders
    Umeå University, Faculty of Medicine, Department of Odontology. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Family Medicine.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Sharif, Zain
    David, Santhosh
    McGrory, Siobhan
    Henein, Michael Y.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology. Molecular & Clinical Sciences Research Institute, St. George University, London, UK.
    Cytokine Disturbances in Coronary Artery Ectasia Do Not Support Atherosclerosis Pathogenesis2018In: International Journal of Molecular Sciences, ISSN 1422-0067, E-ISSN 1422-0067, Vol. 19, no 1, article id 260Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Coronary artery ectasia (CAE) is a rare disorder commonly associated with additional features of atherosclerosis. In the present study, we aimed to examine the systemic immune-inflammatory response that might associate CAE.

    METHODS: Plasma samples were obtained from 16 patients with coronary artery ectasia (mean age 64.9 ± 7.3 years, 6 female), 69 patients with coronary artery disease (CAD) and angiographic evidence for atherosclerosis (age 64.5 ± 8.7 years, 41 female), and 140 controls (mean age 58.6 ± 4.1 years, 40 female) with normal coronary arteries. Samples were analyzed at Umeå University Biochemistry Laboratory, Sweden, using the V-PLEX Pro-Inflammatory Panel 1 (human) Kit. Statistically significant differences (p < 0.05) between patient groups and controls were determined using Mann-Whitney U-tests.

    RESULTS: The CAE patients had significantly higher plasma levels of INF-γ, TNF-α, IL-1β, and IL-8 (p = 0.007, 0.01, 0.001, and 0.002, respectively), and lower levels of IL-2 and IL-4 (p < 0.001 for both) compared to CAD patients and controls. The plasma levels of IL-10, IL-12p, and IL-13 were not different between the three groups. None of these markers could differentiate between patients with pure (n = 6) and mixed with minimal atherosclerosis (n = 10) CAE.

    CONCLUSIONS: These results indicate an enhanced systemic pro-inflammatory response in CAE. The profile of this response indicates activation of macrophages through a pathway and trigger different from those of atherosclerosis immune inflammatory response.

  • 15.
    Brändström, Helge
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Ängquist, Karl-Axel
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery.
    Grip, Helena
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Autonomic nerve system responses for normal and slow rewarmers after hand cold provocation: effects of long-term cold climate training2013In: International Archives of Occupational and Environmental Health, ISSN 0340-0131, E-ISSN 1432-1246, Vol. 86, no 3, p. 357-365Article in journal (Refereed)
    Abstract [en]

    PURPOSE: Differences among individuals concerning susceptibility to local cold injury following acute cold exposure may be related to function of the autonomic nervous system. We hypothesized that there are differences in heart rate variability (HRV) between individuals with normal or more pronounced vasoconstriction following cold exposure and that there is an adaptation related to prolonged cold exposure in autonomic nervous system response to cold stimuli.

    METHODS: Seventy-seven young men performed a cold provocation test, where HRV was recorded during cold hand immersion and recovery. Forty-three subjects were re-examined 15 months later, with many months of cold weather training between the tests. Subjects were analyzed as 'slow' and 'normal' rewarmers according to their thermographic rewarming pattern.

    RESULTS: For the 'pre-training' test, before cold climate exposure, normal rewarmers had higher power for low-frequency (P(LF)) and high-frequency (P(HF)) HRV components during the cold provocation test (ANOVA for groups: p = 0.04 and p = 0.005, respectively). There was an approximately 25 % higher P(HF) at the start in normal rewarmers, in the logarithmic scale. Low frequency-to-high frequency ratio (P(LF)/P(HF)) showed lower levels for normal rewarmers (ANOVA for groups: p = 0.04). During the 'post-training' cold provocation test, both groups lacked the marked increase in heart rate that occurred during cold exposure at the 'pre-training' setting. After cold acclimatization (post-training), normal rewarmers showed lower resting power values for the low-frequency and high-frequency HRV components. After winter training, the slow rewarmers showed reduced low-frequency power for some of the cold provocation measurements but not all (average total P(LF), ANOVA p = 0.05), which was not present before winter training.

    CONCLUSIONS: These HRV results support the conclusion that cold adaptation occurred in both groups. We conclude that further prospective study is needed to determine whether cold adaptation provides protection to subjects at higher risk for cold injury, that is, slow rewarmers.

  • 16.
    Granåsen, Gabriel
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Multivariate Classification of Cardiac Autonomic Function and Echocardiographic Abnormalities2013In: 2013 COMPUTING IN CARDIOLOGY CONFERENCE (CINC), 2013, p. 1151-1154Conference paper (Refereed)
    Abstract [en]

    Abnormalities in the function, physiology and the regulation of the heart can be diagnosed using echocardiography (ECHO) and analysis of heart rate variability (HRV). Patients with transthyretin amyloidosis often present increased wall thickness in the myocardium and/ or autonomic dysfunction. We used a novel approach to analyse the relationship between these findings, using a combination of dimension reduction techniques and model based clustering.

  • 17.
    Grip, Helena
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Öhberg, Fredrik
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Sterner, Ylva
    Karlsson, J Stefan
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Gerdle, Björn
    Classification of neck movement patterns related to whiplash-associated disorders using neural networks2003In: IEEE transactions on information technology in biomedicine, ISSN 1089-7771, Vol. 7, no 4, p. 412-418Article in journal (Refereed)
    Abstract [en]

    This paper presents a new method for classification of neck movement patterns related to Whiplash-associated disorders (WAD) using a resilient backpropagation neural network (BPNN). WAD are a common diagnosis after neck trauma, typically caused by rear-end car accidents. Since physical injuries seldom are found with present imaging techniques, the diagnosis can be difficult to make. The active range of the neck is often visually inspected in patients with neck pain, but this is a subjective measure, and a more objective decision support system, that gives a reliable and more detailed analysis of neck movement pattern, is needed. The objective of this study was to evaluate the predictive ability of a BPNN, using neck movement variables as input. Three-dimensional (3-D) neck movement data from 59 subjects with WAD and 56 control subjects were collected with a ProReflex system. Rotation angle and angle velocity were calculated using the instantaneous helical axis method and motion variables were extracted. A principal component analysis was performed in order to reduce data and improve the BPNN performance. BPNNs with six hidden nodes had a predictivity of 0.89, a sensitivity of 0.90 and a specificity of 0.88, which are very promising results. This shows that neck movement analysis combined with a neural network could build the basis of a decision support system for classifying suspected WAD, even though further evaluation of the method is needed.

  • 18. Guo, Li
    et al.
    Berglin, Lena
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Mattila, Heikki
    Design of a garment-based sensing system for breathing monitoring2013In: Textile research journal, ISSN 0040-5175, E-ISSN 1746-7748, Vol. 83, no 5, p. 499-509Article in journal (Refereed)
    Abstract [en]

    The long-term monitoring of biophysiological signals requires new types of sensor systems that are wearable and at the same time convenient for the users. This paper describes the design of a novel garment-based sensing system for the long-term monitoring of breathing rhythm. The system concept was realized in a prototype garment, integrated with coated piezoresistive sensors. The prototype garment was tested by five subjects, and compared with a standard piezoelectric respiratory belt. Each signal was quantitatively and qualitatively evaluated in the time and frequency domain to make sure that no medical and diagnostic information was lost. The results showed a good agreement between the garment-based sensors and the standard reference, where errors occurred only when the breathing rate was extremely high. The garment-based sensor system could also distinguish the predominance breathing compartment (chest versus abdominal breathing). The system could detect a 10 s pause in breathing, which could be of importance in studies of sleep apnea. A garment-based sensing system maintains the accuracy of the signal quality without reducing the comfort for the user. It makes possible long-term ambulatory monitoring and has home-based healthcare applications.

  • 19.
    Gustafsson, Sandra
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Granåsen, Gabriel
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Grönlund, Christer
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Suhr, Ole B.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Discriminating hereditary transthyretin cardiomyopathy from hypertrophic cardiomyopathy using an echocardiographic and ECG based classification tree2014In: European Heart Journal, ISSN 0195-668X, E-ISSN 1522-9645, Vol. 35, no Supplement 1, Meeting abstract P5254, p. 929-929Article in journal (Other academic)
  • 20.
    Gustavsson, Sandra
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Granåsen, Gabriel
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Grönlund, Christer
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Mörner, Stellan
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Henein, Michael
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Suhr, Ole B
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Can echocardiography and ECG discriminate hereditary transthyretin V30M amyloidosis from hypertrophic cardiomyopathy?2015In: Amyloid: Journal of Protein Folding Disorders, ISSN 1350-6129, E-ISSN 1744-2818, Vol. 22, no 3, p. 163-170Article in journal (Refereed)
    Abstract [en]

    Objective: Hereditary transthyretin (ATTR) amyloidosis with increased left ventricular wall thickness could easily be misdiagnosed by echocardiography as hypertrophic cardiomyopathy (HCM). Our aim was to create a diagnostic tool based on echocardiography and ECG that could optimise identification of ATTR amyloidosis. Methods: Data were analysed from 33 patients with biopsy proven ATTR amyloidosis and 30 patients with diagnosed HCM. Conventional features from ECG were acquired as well as two dimensional and Doppler echocardiography, speckle tracking derived strain and tissue characterisation analysis. Classification trees were used to select the most important variables for differentiation between ATTR amyloidosis and HCM. Results: The best classification was obtained using both ECG and echocardiographic features, where a QRS voltage >30 mm was diagnostic for HCM, whereas in patients with QRS voltage <30 mm, an interventricular septal/posterior wall thickness ratio (IVSt/PWt) >1.6 was consistent with HCM and a ratio <1.6 supported the diagnosis of ATTR amyloidosis. This classification presented both high sensitivity (0.939) and specificity (0.833). Conclusion: Our study proposes an easily interpretable classification method for the differentiation between HCM and increased left ventricular myocardial thickness due to ATTR amyloidosis. Our combined echocardiographic and ECG model could increase the ability to identify ATTR cardiac amyloidosis in clinical practice.

  • 21.
    Haney, Michael F.
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Can heart rate variability become a screening tool for anesthesia-related hypotension?2007In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 51, no 10, p. 1289-1291Article in journal (Refereed)
  • 22.
    Hedelin, Rikard
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Bjerle, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Henriksson-Larsén, K
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Sports Medicine.
    Cardiac autonomic imbalance in an overtrained athlete.2000In: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 32, no 9, p. 1531-1533Article in journal (Refereed)
    Abstract [en]

    PURPOSE: In order to investigate overtraining-related adaptations in the autonomic nervous system, cardiac autonomic activity was examined in a junior cross-country skier who presented with reduced performance in competitions, early breathlessness during training sessions, and accumulated central fatigue. METHODS: Power spectral analysis of heart rate variability (HRV) was performed before, when overtrained (OT), and after recovery (Rec). RESULTS: In the overtrained state, high frequency (HF) and total powers in the lying position were higher compared with before and after. In normalized units, the increased HF in OT was even more prominent and clearly higher than in any control subject, and it was reversed in Rec. Resting heart rate was slightly reduced in OT and returned to baseline in Rec. CONCLUSIONS: The shift toward increased heart rate variability, particularly in the HF range, together with a reduced resting heart rate suggest a cardiac autonomic imbalance with extensive parasympathetic modulation in this athlete when overtrained.

  • 23.
    Heldestad, Victoria
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Hörnsten, Rolf
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Obayashi, Konen
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Suhr, Ole B
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Nordh, Erik
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Comparison of quantitative sensory testing and heart rate variability in Swedish Val30Met ATTR2011In: Amyloid: Journal of Protein Folding Disorders, ISSN 1350-6129, E-ISSN 1744-2818, Vol. 18, no 4, p. 183-190Article in journal (Refereed)
    Abstract [en]

    Patients with transthyretin amyloidosis (ATTR) polyneuropathy, a hereditary fatal disease, often report defects in both thermal perception and autonomic nervous system function as their first clinical symptoms. While elevated thermal perception thresholds (TPT) for cold and warmth only recently have been shown as an early marker of small nerve fiber dysfunction in these patients, heart rate variability (HRV) has frequently been used to quantify autonomic neuropathy. The main purpose with this report was to elucidate a possible relationship between estimates of HRV and TPT in a selected group of early and late-onset Swedish Val30Met ATTR patients. The results show significantly more pronounced elevation of TPT in early compared to late-onset patients. Significant correlations between HRV and TPT were found among late-onset cases, indicating a possible relationship between loss of thin nerve fibers in somatic and autonomic nerves, while generally no such relationships were found among early-onset cases. This observation emphasizes the importance of testing both HRV and TPT to ensure optimal early detection of neuropathic changes in an as wide as possible range of small nerve fibers in suspected ATTR patients. This is of particular importance as the phenotype of the ATTR disease varies between groups with different age of onset.

  • 24.
    Henein, Michael
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Granåsen, Gabriel
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Schmermund, Axel
    Guerci, Alan
    Erbel, Raimund
    Raggi, Paolo
    High dose and long-term statin therapy accelerate coronary artery calcification2015In: International Journal of Cardiology, ISSN 0167-5273, E-ISSN 1874-1754, Vol. 184, p. 581-586Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: In randomized clinical trials statins and placebo treated patients showed the same degree of coronary artery calcium (CAC) progression. We reanalyzed data from two clinical trials to further investigate the time and dose dependent effects of statins on CAC. Additionally, we investigated whether CAC progression was associated with incident cardiovascular events.

    METHODS AND RESULTS: Data were pooled from two clinical trials: St. Francis Heart Study (SFHS) (419 and 432 patients treated with placebo and 20mg atorvastatin daily, respectively) and EBEAT Study (164 and 179 patients respectively treated with 10mg and 80mg atorvastatin daily). CAC scores were assessed at baseline, 2years and 4-6years in SFHS; in EBEAT they were measured at baseline and 12months. After a short-term follow-up (12 to 24months) placebo and low dose atorvastatin showed a similar CAC increase, although 80mg/daily atorvastatin increased CAC an additional 12-14% over placebo (p<0.001). In the long-term, atorvastatin caused a greater progression of CAC compared to placebo (additional 1.1%, p=0.04). In SFHS 42 cardiovascular events occurred after the second CT scan. The baseline and progression of CAC were greater in patients with events. However, only baseline CAC and family history of premature cardiovascular disease but not CAC progression were independent predictors of events.

    CONCLUSIONS: Despite a greater CAC increase with high dose and long-term statin therapy, events did not occur more frequently in statin treated patients. This suggests that CAC growth under treatment with statins represents plaque repair rather than continuing plaque expansion.

  • 25.
    Henein, Michael
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Nicoll, Rachel
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Schmermund, A.
    Diederichsen, A. C. P.
    Mickley, H.
    Zamorano, P.
    Gueret, P.
    Budoff, M. J.
    European Calcific Coronary Artery Disease (Euro-CCAD) study: the additional value of coronary calcification, to angiography, in investigating angina patients2013In: European Heart Journal, ISSN 0195-668X, E-ISSN 1522-9645, Vol. 34, no Supplement: 1, p. 177-177Article in journal (Other academic)
    Abstract [en]

    Background and aim: This study is a part of the Euro-CCAD (CalcificCoronary Artery Disease) project, investigating the geographic prevalence of a coronary artery calcium (CAC) score of >400 in patients with no flow-limiting lesions (FLL) as a potential cause for stable angina. With the development of computerized tomographic coronaryangiography (CTCA), assessment of CAC has become less fashionable, although CTCA often fails to determine the exact cause of symptoms in the absence of FLLs.

    Methods: Data from consecutive symptomatic intermediate risk patients (as defined by guidelines), who had both CA and calcium scoring, were compared between USA and Europe as well as between Europeancountries (Denmark, Germany, France and Spain). No patient had a priorcoronary event, intervention, valve disease or kidney failure.

    Results: The inclusion criteria were fulfilled in 4,444 patients, (60% males), mean age 59.3 years (SD 11.3 years). The prevalence of FLL was higher in the USA at 53% (983/1851) than in Europe at 34% (870/2593) as a whole, (p<0.001). The FLL prevalence was also different (p<0.001) within Europe: Denmark 16%, Germany 35%, France 46% and Spain 89%. In patients with no FLL, 9% had CAC >400, with no difference in prevalence between the USA and Europe, irrespective of age and gender. However, within Europe the prevalence of patients without FLL and with a CAC score >400 differed: Spain 22%, Germany 13%, France 10% and Denmark 7%. Within the total patient population 22% of those with CAC score >400 had no FLL.

    Conclusion: Despite the known variability in the current management of symptomatic angina patients at intermediate risk between the USA andEuropean countries, a consistent proportion (nearly 10%) exhibits severe CAC in the absence of flow limiting lesions. The presence of severe CAC could explain their symptoms through compromised coronary flow reserve. These results highlight the potential value of obtaining additional anatomical information by using CAC assessment in symptomatic patients.

  • 26.
    Henein, Michael Y.
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology. Umeå Heart Centre.
    Koulaouzidis, George
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology. Umeå Heart Centre.
    Granåsen, Gabriel
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Guerci, Alan
    Department of Research, St Francis Hospital, Roslyn, NY, USA.
    Schmermund, Axel
    Bethanien Hospital, Frankfurt, Germany.
    The natural history of coronary calcification: a meta-analysis from St Francis and EBEAT trials2013In: International Journal of Cardiology, ISSN 0167-5273, E-ISSN 1874-1754, Vol. 168, no 4, p. 3944-3948Article in journal (Refereed)
    Abstract [en]

    BACKGROUND AND AIM: Coronary artery calcium score (CACs) is an established quantitative tool for assessing subclinical atherosclerosis. The aim of this study was to assess in a meta-analysis model the natural history and reproducibility of CACs measurements obtained from St Francis and EBEAT trials.

    METHODS: We analysed data from 649 individuals: 443 on placebo with 2year follow-up from St Francis trial (Study A) and 209 on 10mg atorvastatin with 1year follow-up of EBEAT trial (Study B). Total CACs and that in the left coronary artery (LCA) branches, left main stem (LMS), left anterior descending (LAD), left circumflex (Cx) and right coronary artery (RCA) were analysed. In view of the wide CACs spectrum, data were logarithmically transformed before the analyses and mixed model analysis was used to evaluate the change of CACs over time.

    RESULTS: The overall agreement between the two measurements was fairly good, showing a small but significant increase in CAC: 68% of the group as a whole presented an increase in CACs, 23% of the cohort had negligible change in CACs of <10% irrespective of the baseline CACs; and the remaining 10% showed a fall in CACs. Both studies showed similar patterns. The analysis of individual coronary arteries showed significantly higher variability of measurements in the RCA than in the LCA. Males had higher baseline CACs than females, but the rate of progression was not different between genders, irrespectively of age and baseline score.

    CONCLUSION: The natural history of CACs was overtime progression in the majority of subjects, irrespective of gender. The higher variability in RCA measurements could be related to the low baseline CACs or exaggerated movement of the right side atrioventricular ring, whereas those for LCA branches are influenced by the branch allocation of the CACs. Large changes to and from zero, might be related to technical limitations.

  • 27.
    Henein, Michael Y.
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Nicoll, Rachel
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Schmermund, A.
    Diederichsen, A. C. P.
    Mickley, H.
    Zamorano, P.
    Gueret, P.
    Budoff, M. J.
    European Calcific Coronary Artery Disease (Euro-CCAD) study: the relationship between coronary calcification and flow limiting lesion in symptomatic patients2013In: European Heart Journal, ISSN 0195-668X, E-ISSN 1522-9645, Vol. 34, no Supplement: 1, p. 723-723Article in journal (Other academic)
    Abstract [en]

    Background and aim: This study is a part of the Euro-CCAD (CalcificCoronary Artery Disease) project, investigating the geographic prevalence of a coronary artery calcium (CAC) score of >400 in patients with no flow-limiting lesions (FLL) as a potential cause for stable angina. With the development of computerized tomographic coronaryangiography (CTCA), assessment of CAC has become less fashionable, although CTCA often fails to determine the exact cause of symptoms in the absence of FLLs.

    Methods: Data from consecutive symptomatic intermediate risk patients (as defined by guidelines), who had both CA and calcium scoring, were compared between USA and Europe as well as between Europeancountries (Denmark, Germany, France and Spain). No patient had a priorcoronary event, intervention, valve disease or kidney failure.

    Results: The inclusion criteria were fulfilled in 4,444 patients, (60% males), mean age 59.3 years (SD 11.3 years). The prevalence of FLL was higher in the USA at 53% (983/1851) than in Europe at 34% (870/2593) as a whole, (p<0.001). The FLL prevalence was also different (p<0.001) within Europe: Denmark 16%, Germany 35%, France 46% and Spain 89%. In patients with no FLL, 9% had CAC >400, with no difference in prevalence between the USA and Europe, irrespective of age and gender. However, within Europe the prevalence of patients without FLL and with a CAC score >400 differed: Spain 22%, Germany 13%, France 10% and Denmark 7%. Within the total patient population 22% of those with CAC score >400 had no FLL.

    Conclusion: Despite the known variability in the current management of symptomatic angina patients at intermediate risk between the USA andEuropean countries, a consistent proportion (nearly 10%) exhibits severe CAC in the absence of flow limiting lesions. The presence of severe CAC could explain their symptoms through compromised coronary flow reserve. These results highlight the potential value of obtaining additional anatomical information by using CAC assessment in symptomatic patients.

  • 28.
    Hörnsten, Rolf
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Pennlert, Johanna
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Jensen, Steen M
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Suhr, Ole B
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Heart complications in familial transthyretin amyloidosis: impact of age and gender.2010In: Amyloid: Journal of Protein Folding Disorders, ISSN 1350-6129, E-ISSN 1744-2818, Vol. 17, no 2, p. 63-68Article in journal (Refereed)
    Abstract [en]

    Heart arrhythmia is common in Swedish patients with familial amyloidotic polyneuropathy (FAP), as well as cardiomyopathy. We investigated the relationship between Holter ECG and echocardiographic findings in 108 FAP patients, with particular focus on age and gender differences. Female patients were younger than male patients at symptom onset (p < 0.01). Only 4 of 39 patients with septal hypertrophy were females. Regression analysis showed that age of onset, gender and duration of disease were significantly related with intraventricular septum (IVS) thickness. Sixty-five patients (25 females) presented with abnormal 24-h ECG recordings. IVS thickness was not significantly related to conduction disturbances or the presence of ventricular arrhythmia (VA). However, IVS thickness and atrial dimension were both related to increased rate of supraventricular arrhythmia (SVA). Male gender was clearly associated with more pronounced septal thickness of the heart. Conduction disturbances were not related to IVS thickness, indicating that the distribution and extent of infiltration of the heart by amyloid are heterogeneous and related to gender and age of onset. These findings highlight the necessity of 24-h ECGs to detect conduction disturbances, due to their occurrence in the absence of echocardiographic evidence of amyloid deposition in the myocardium.

  • 29.
    Hörnsten, Rolf
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Suhr, Ole B
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Jensen, Steen M
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Outcome of heart rate variability and ventricular late potentials after liver transplantation for familial amyloidotic polyneuropathy2008In: Amyloid: Journal of Protein Folding Disorders, ISSN 1350-6129, E-ISSN 1744-2818, Vol. 15, no 3, p. 187-195Article in journal (Refereed)
    Abstract [en]

    Reduced heart rate variability (HRV) is common in familial amyloidotic polyneuropathy (FAP), as well as cardiac arrhythmias. We examined the effects of liver transplantation (LTx) on 24-h HRV and ventricular late potentials. Twenty-one liver-transplanted FAP patients underwent Holter-ECG recordings and signal average electrocardiography recordings (SAECG) before and after LTx. Mean follow-up time after LTx was 21.7 months. Three patients had marked increased HRV after LTx, but this was in all cases caused by the development of subtle atrial arrhythmia and did not reflect an improvement in the cardiac autonomic control. In total, ten patients were excluded from analysis of HRV because of arrhythmia. Spectral analysis of HRV showed no significant differences before and after LTx in the remaining 11 patients. Positive late potentials were found in 33% of patients before LTx and this proportion was unchanged after LTx. Reduced HRV and positive late potentials are common in Swedish FAP patients, and remain stable, at least within the short term after transplantation. If an increase of HRV after transplantation is observed, it should raise the suspicion that the patient has developed subtle atrial arrhythmia.

  • 30.
    Hörnsten, Rolf
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Suhr, Ole B.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Olofsson, Bert-Ove
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Arrhythmia - a pitfall in tests of cardiac autonomic function after liver transplantation for familial amyloidotic polyneuropathy: a long-term follow-up of Swedish patients2012In: Amyloid: Journal of Protein Folding Disorders, ISSN 1350-6129, E-ISSN 1744-2818, Vol. 19, no 2, p. 81-86Article in journal (Refereed)
    Abstract [en]

    Liver transplantation (LT) is a potentially curative treatment for hereditary transthyretin amyloidosis, of which familial amyloid polyneuropathy (FAP) is the most common form in Sweden. This study investigated the long-term development in heart rate variability (HRV) after LT in Swedish FAP patients. HRV was analyzed before LT, and during a first (<40 months) and a second (>40 months) follow-up recording after transplantation, respectively. Power spectrum analysis was performed on 2-min sequences in the supine position and after passive tilt, after careful identification of patients with arrhythmia. Data were obtained from 33 patients, but 18 patients had developed cardiac arrhythmia or were pacemaker-treated (4 before LT and 14 after LT) and three patients had not performed the first follow-up recording. In the remaining 12 patients, HRV decreased between the pretransplant evaluation and the first follow-up, thereafter no significant changes were found. In conclusion, our study showed that the progressive development of cardiac arrhythmias after LT is a major pitfall when assessing cardiac autonomic function in FAP patients, especially in patients older than 40 years. In the minority of patients with sinus rhythm in all recordings, cardiac autonomic modulation remained stable after transplantation and no improvement was noted.

  • 31.
    Hörnsten, Rolf
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Olofsson, Bert-Ove
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Jensen, Steen M
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Suhr, Ole B
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Liver transplantation does not prevent the development of life-threatening arrhythmia in familial amyloidotic polyneuropathy, Portuguese-type (ATTR Val30Met) patients2004In: Transplantation, ISSN 0041-1337, E-ISSN 1534-6080, Vol. 78, no 1, p. 112-116Article in journal (Other academic)
  • 32.
    Hörnsten, Rolf
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Suhr, Ole B
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Jensen, Steen
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Ventricular late potentials in familial amyloidotic polyneuropathy2006In: Journal of Electrocardiology, ISSN 0022-0736, E-ISSN 1532-8430, Vol. 39, no 1, p. 57-62Article in journal (Refereed)
    Abstract [en]

    It is well known that cytokines are highly involved in the disease process of rheumatoid arthritis (RA). Recently, targeting of neuropeptides has been suggested to have potential therapeutic effects in RA. The aim of this study was to investigate possible interrelations between five neuropeptides (bombesin/gastrin-releasing peptide (BN/GRP), substance P (SP), vasoactive intestinal peptide, calcitonin-gene-related peptide, and neuropeptide Y) and the three cytokines tumour necrosis factor (TNF)-alpha, IL-6, and monocyte chemoattractant protein-1 in synovial fluid of patients with RA. We also investigated possible interrelations between these neuropeptides and soluble TNF receptor 1 in serum from RA patients. Synovial fluid and sera were collected and assayed with ELISA or RIA. The most interesting findings were correlations between BN/GRP and SP and the cytokines. Thus, in synovial fluid, the concentrations of BN/GRP and SP grouped together with IL-6, and SP also grouped together with TNF-alpha and monocyte chemoattractant protein-1. BN/GRP and SP concentrations in synovial fluid also grouped together with the erythrocyte sedimentation rate. In the sera, BN/GRP concentrations and soluble TNF receptor 1 concentrations were correlated. These results are of interest because blocking of SP effects has long been discussed in relation to RA treatment and because BN/GRP is known to have trophic and growth-promoting effects and to play a role in inflammation and wound healing. Furthermore, the observations strengthen a suggestion that combination treatment with agents interfering with neuropeptides and cytokines would be efficacious in the treatment of RA. In conclusion, BN/GRP and SP are involved together with cytokines in the neuroimmunomodulation that occurs in the arthritic joint.

  • 33.
    Karlsson, Björn-Markus
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Lindkvist, Marie
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health. Umeå University, Faculty of Social Sciences, Umeå School of Business and Economics (USBE), Statistics.
    Lindkvist, Markus
    Karlsson, Marcus
    Lundström, Ronnie
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine.
    Håkansson, Stellan
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    van den Berg, Johannes
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Sound and vibration: effects on infants' heart rate and heart rate variability during neonatal transport2012In: Acta Paediatrica, ISSN 0803-5253, E-ISSN 1651-2227, Vol. 101, no 2, p. 148-154Article in journal (Refereed)
    Abstract [en]

    Aim: To measure the effect of sound and whole-body vibration on infants' heart rate and heart rate variability during ground and air ambulance transport.

    Methods: Sixteen infants were transported by air ambulance with ground ambulance transport to and from the airports. Whole-body vibration and sound levels were recorded and heart parameters were obtained by ECG signal.

    Results: Sound and whole-body vibration levels exceeded the recommended limits. Mean whole-body vibration and sound levels were 0.19m/s(2) and 73dBA, respectively. Higher whole-body vibration was associated with a lower heart rate (p<0.05), and higher sound level was linked to a higher heart rate (p=0.05). The heart rate variability was significantly higher at the end of the transport than at the beginning (p<0.01). Poorer physiologic status was associated with lower heart rate variability (p<0.001) and a lower heart rate (p<0.01). Infants wearing earmuffs had a lower heart rate (p<0.05).

    Conclusions: Sound and whole-body vibration during neonatal transport exceed recommended levels for adults and sound seem to have a more stressful effect on the infant than vibrations. Infants should wear earmuffs during neonatal transport because of the stress reducing effect.

  • 34. Karlsson, M
    et al.
    Forsgren, R
    Eriksson, E
    Edstrom, U
    Backlund, T
    Karlsson, J
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Radiation Sciences.
    Wireless system for real-time recording of heart rate variability for home nursing.2005In: Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference, ISSN 1557-170X, Vol. 4, p. 3717-9Article in journal (Refereed)
    Abstract [en]

    Modern wireless communication technologies offer new possibilities for patient monitoring in hospitals, as well as at home or in outdoor environments. In this paper, we present a wireless system for ECG recordings and real-time analysis of heart rate variability (HRV). The system also makes it possible for distance consultation, for example with a specialist in cardiology, with the help of a WEB-solution.

  • 35.
    Karlsson, Marcus
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Hörnsten, Rolf
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Rydberg, Annika
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Automatic filtering of outliers in RR intervals before analysis of heart rate variability in Holter recordings: a comparison with carefully edited data.2012In: Biomedical engineering online, ISSN 1475-925X, E-ISSN 1475-925X, Vol. 11, no 2, p. 12-Article in journal (Refereed)
    Abstract [en]

    Background: Undetected arrhythmic beats seriously affect the power spectrum of the heart rate variability (HRV). Therefore, the series of RR intervals are normally carefully edited before HRV is analysed, but this is a time consuming procedure when 24-hours recordings are analysed. Alternatively, different methods can be used for automatic removal of arrhythmic beats and artefacts. This study compared common frequency domain indices of HRV when determined from manually edited and automatically filtered RR intervals.

    Methods and Results: Twenty-four hours Holter recordings were available from 140 healthy subjects of age 1-75 years. An experienced technician carefully edited all recordings. Automatic filtering was performed using a recursive procedure where RR intervals were removed if they differed from the mean of the surrounding RR intervals with more than a predetermined limit (ranging from 10% to 50%). The filtering algorithm was evaluated by replacing 1% of the beats with synthesised ectopic beats. Power spectral analysis was performed before and after filtering of both the original edited data and the noisy data set. The results from the analysis using the noisy data were used to define an age-based filtering threshold. The age-based filtration was evaluated with completely unedited data, generated by removing all annotations from the series of RR intervals, and then comparing the resulting HRV indices with those obtained using edited data. The results showed equivalent results after age-based filtration of both the edited and unedited data sets, where the differences in HRV indices obtained by different preprocessing methods were small compared to the mean values within each age group.

    Conclusions: The study showed that it might not be necessary to perform the time-consuming careful editing of all detected heartbeats before HRV is analysed in Holter recordings.

    In most subjects, it is sufficient to perform the regular editing needed for valid arrhythmia analyses, and then remove undetected ectopic beats and artefacts by age-based filtration of the series of RR intervals, particularly in subjects older than 30 years.

  • 36.
    Kesek, Milos
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Gustavsson, Ola
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Nondipolar content of T wave derived from a myocardial source simulation with increased repolarization inhomogeneity.2009In: Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc, ISSN 1542-474X, Vol. 14, no 2, p. 185-192Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Several conditions with repolarization disturbances are associated with increased level of nondipolar components of the T wave. The nondipolar content has been proposed as a measure of repolarization inhomogeneity. This computer simulation study examines the link between increased nondipolar components and increased repolarization inhomogeneity in an established model. METHODS: The simulation was performed with Ecgsim software that uses the equivalent double-layer source model. In the model, the shape of transmembrane potential is derived from biological recordings. Increased repolarization inhomogeneity was simulated globally by increasing the variance in action potential duration and locally by introducing changes mimicking acute myocardial infarction. We synthesized surface ECG recordings with 12, 18, and 300 leads. The T-wave residue was calculated by singular value decomposition. The study examined the effects of the number of ECG leads, changes in definition of end of T wave and random noise added to the signal. RESULTS: Normal myocardial source gave a low level of nondipolar content. Increased nondipolar content was observed in the two types of increased repolarization inhomogeneity. Noise gave a large increase in the nondipolar content. The sensitivity of the result to noise increased when a higher number of principal components were used in the computation. CONCLUSIONS: The nondipolar content of the T wave was associated with repolarization inhomogeneity in the computer model. The measure was very sensitive to noise, especially when principal components of high order were included in the computations. Increased number of ECG leads resulted in an increased signal-to-noise ratio.

  • 37. Kleyko, Denis
    et al.
    Osipov, Evgeny
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    A Hyperdimensional Computing Framework for Analysis of Cardiorespiratory Synchronization During Paced Deep Breathing2019In: IEEE Access, E-ISSN 2169-3536, Vol. 7, p. 34403-34415Article in journal (Refereed)
    Abstract [en]

    Autonomic function during deep breathing (DB) is normally scored based on the assumption that the heart rate is synchronized with the breathing. We have observed individuals with subtle arrhythmias during DB, where an autonomic function cannot be evaluated. This paper presents a novel method for analyzing cardiorespiratory synchronization: feature-based analysis of the similarity between heart rate and respiration using the principles of hyperdimensional computing. Heart rate and respiration signals were modeled using Fourier series analysis. Three feature variables were derived and mapped to binary vectors in a high-dimensional space. Using both synthesized data and recordings from patients/healthy subjects, the similarity between the feature vectors was assessed using Hamming distance (high-dimensional space), Euclidean distance (original space), and with a coherence-based index. Methods were evaluated via the classification of the similarity indices into three groups. The distance-based methods achieved good separation of signals into classes with different degrees of cardiorespiratory synchronization, also providing identification of patients with low cardiorespiratory synchronization but high values of conventional DB scores. Moreover, binary high-dimensional vectors allowed an additional analysis of the obtained Hamming distance. Feature-based similarity analysis using hyperdimensional computing is capable of identifying signals with low cardiorespiratory synchronization during DB due to arrhythmias. Vector-based similarity analysis could be applied to other types of feature variables than based on spectral analysis. The proposed methods for robustly assessing cardiorespiratory synchronization during DB facilitate the identification of individuals where the evaluation of the autonomic function is problematic or even impossible, thus increasing the correctness of the conventional DB scores.

  • 38.
    Koulaouzidis, George
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology. Umeå Heart Centre.
    Henein, Michael Y.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology. Umeå Heart Centre.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Guerci, A.
    Schmermund, A.
    The Natural History of Coronary Calcification: A meta-analysis from St Francis and EBEAT trials2013In: European Journal of Cardiovascular Nursing, ISSN 1474-5151, E-ISSN 1873-1953, Vol. 12, no Supplement: 1, p. S5-S5, Meeting Abstract: P18Article in journal (Other academic)
  • 39.
    Lindgren, Lenita
    et al.
    Umeå University, Faculty of Medicine, Department of Nursing. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Lehtipalo, Stefan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Winsö, Ola
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Brulin, Christine
    Umeå University, Faculty of Medicine, Department of Nursing.
    Touch massage: a pilot study of a complex intervention2013In: Nursing in Critical Care, ISSN 1362-1017, E-ISSN 1478-5153, Vol. 18, no 6, p. 269-277Article in journal (Refereed)
    Abstract [en]

    Objectives: To report and evaluate a complex touch massage intervention according to the British Medical Research Council framework. This study aimed to evaluate the effects of touch massage on levels of anxiety and physiological stress in patients scheduled for elective aortic surgery.

    Background: The use of touch massage has increased during the past decade but no systematic studies have been implemented to investigate the effectiveness of such treatment. It is important to conduct multidisciplinary investigations into the effects of complex interventions such as touch massage. For this, the British Medical Research Council has provided a useful framework to guide the development, piloting, evaluation and reporting of complex intervention studies.

    Method: A pilot study with a randomized controlled design including 20 patients (10 + 10) scheduled for elective aortic surgery. Selected outcome parameters included; self-reported anxiety, measured by the State-Trait Anxiety Inventory Form Y instrument, and physiological stress, measured by heart rate variability, blood pressure, respiratory frequency, oxygen saturation and concentrations of cortisol, insulin and glucose in serum.

    Results: There were significant differences in self-reported anxiety levels before and after touch massage (p = 0·007), this was not observed in the control group (p = 0·833). There was a significant difference in self-reported anxiety levels between the touch massage group and the control group after touch massage and rest (p = 0·001). There were no significant differences in physiological stress-related outcome parameters between patients who received touch massage and controls.

    Conclusion: In our study, touch massage decreased anxiety levels in patients scheduled for elective aortic surgery, and the British Medical Research Council framework was a useful guideline for the development, evaluation and reporting of a touch massage intervention.

    Relevance to clinical practice: Touch massage can reduce patients' anxiety levels and is thus an important nursing intervention in intensive and post-operative care.

  • 40.
    Lindgren, Lenita
    et al.
    Umeå University, Faculty of Medicine, Department of Nursing. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Rundgren, S
    Umeå University, Faculty of Medicine, Department of Nursing.
    Winsö, Ola
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Lehtipalo, Stefan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Karlsson, Markus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Stenlund, Hans
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Epidemiology and Global Health.
    Jacobsson, Catrine
    Umeå University, Faculty of Medicine, Department of Nursing.
    Brulin, Christine
    Umeå University, Faculty of Medicine, Department of Nursing.
    Physiological responses to touch massage in healthy volunteers2010In: Autonomic Neuroscience: Basic & Clinical, ISSN 1566-0702, E-ISSN 1872-7484, Vol. 158, no 1-2, p. 105-110Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: To evaluate effects of touch massage (TM) on stress responses in healthy volunteers.

    METHODS: A crossover design including twenty-two (mean age=28.2) healthy volunteers (11 male and 11 female) cardiac autonomic tone was measured by heart rate (HR) and heart rate variability (HRV). Stress hormone levels (cortisol) were followed in saliva. We also measured blood glucose and serum insulin. Extracellular (ECV) levels of glucose, lactate, pyruvate and glycerol were followed using the microdialysis technique (MD). TM was performed on hands and feet for 80min, during control, participants rested in the same setting. Data were collected before, during, and after TM and at rest. Saliva cortisol, serum glucose, and serum insulin were collected before, immediately following, and 1h after intervention or control, respectively.

    RESULTS: After 5min TM, HR decreased significantly, indicating a reduced stress response. Total HRV and all HRV components decreased during intervention. Saliva cortisol and insulin levels decreased significantly after intervention, while serum glucose levels remained stable. A similar, though less prominent, pattern was seen during the control situation. Only minor changes were observed in ECV levels of glucose (a decrease) and lactate (an increase). No significant alterations were observed in glycerol or pyruvate levels throughout the study. There were no significant differences between groups in ECV concentrations of analyzed substances.

    CONCLUSIONS: In healthy volunteers, TM decreased sympathetic nervous activity, leading to decreased overall autonomic activity where parasympathetic nervous activity also decreased, thereby maintaining the autonomic balance.

  • 41.
    Lindmark, Stina
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Lönn, Lars
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Tufvesson, Magnus
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Olsson, Tommy
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Eriksson, Jan W
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Dysregulation of the autonomic nervous system can be a link between visceral adiposity and insulin resistance2005In: Obesity Research, ISSN 1071-7323, E-ISSN 1550-8528, Vol. 13, no 4, p. 717-728Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: To evaluate the interplay among abdominal adipose tissue distribution, the cortisol axis, the autonomic nervous system, and insulin resistance. RESEARCH METHODS AND PROCEDURES: Two age-, sex-, and BMI-matched groups were studied. Fifteen subjects were first-degree relatives of patients with type 2 diabetes (R), and 15 had no family history of diabetes (controls, C). A hyperinsulinemic euglycemic clamp, cortisol measurements, and analysis of heart rate variability (HRV) were performed. Computed tomography was performed in a subgroup (n = 9 + 9) to determine abdominal adipose tissue distribution. RESULTS: R tended to be less insulin-sensitive than C (M value 9.2 +/- 1.0 vs 10.3 +/- 0.7 mg/kg per minute, not significant). Stimulation with tetracosactin or corticotropin releasing hormone yielded lower peak serum cortisol levels in R (p = 0.03 and p = 0.06, respectively). The amount of visceral abdominal fat (VAT) tended to be greater in R. In all subjects, VAT was negatively correlated to insulin sensitivity (r = -0.93, p < 0.001). There was a positive association between VAT and resting heart rate (r = 0.70, p = 0.003) and sympathetic/parasympathetic ratio in HRV assessment after tilt (r = 0.53, p = 0.03). Subcutaneous abdominal tissue was not associated with insulin sensitivity or any of the hormonal or HRV assessments. DISCUSSION: Subjects genetically predisposed for type 2 diabetes had a tendency toward a larger amount of VAT and to lower insulin sensitivity compared with control subjects. The amount of visceral fat was strongly associated with insulin resistance and signs of a high ratio of sympathetic vs. parasympathetic reactivity. A large amount of visceral fat may act in concert with sympathetic/parasympathetic imbalance to promote the development of insulin resistance, and this may be partly independent of genetic background.

  • 42.
    Lindmark, Stina
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology. Umeå University, Faculty of Science and Technology, Centre for Biomedical Engineering and Physics (CMTF).
    Bjerle, P
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Eriksson, JW
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Does the autonomic nervous system play a role in the development of insulin resistance?: a study on heart rate variability in first-degree relatives of type 2 diabetes patients and control subjects2003In: Diabetic Medicine, ISSN 0742-3071, E-ISSN 1464-5491, Vol. 20, no 5, p. 399-405Article in journal (Refereed)
    Abstract [en]

    Aims To investigate dysregulation of the autonomic nervous system as a potential mechanism for early insulin resistance in the development of Type 2 diabetes.

    Methods Thirteen healthy individuals with first-degree relatives with Type 2 diabetes (R) were compared with 14 control subjects without family history of diabetes (C), matched for age, body mass index and sex. An oral glucose tolerance test and a hyperinsulinaemic euglycaemic clamp were performed. Analysis of heart rate variability during rest, controlled breathing, an orthostatic manoeuvre and a standardized physical stress (cold pressor test (CPT)), were used to evaluate the activity of the autonomic nervous system.

    Results Fasting blood glucose, HbA1c and serum insulin were similar in the R and C groups. The M-value, reflecting insulin sensitivity, did not differ significantly between the groups. Total spectral power and high-frequency power were lower in R during controlled breathing (P = 0.05 and P = 0.07, respectively), otherwise there were no significant differences between R and C in heart rate variability. However, low-frequency (LF)/high-frequency (HF) spectral power ratio during CPT, reflecting sympathetic/parasympathetic balance, was negatively associated with insulin sensitivity (r = −0.53, P = 0.006). When all subjects were divided into two groups by the mean M-value, the low M-value group displayed an overall higher LF/HF ratio (P = 0.04). HF power was lower in the low M-value group during controlled breathing and CPT (P = 0.01 and P = 0.03, respectively).

    Conclusion An altered balance of the parasympathetic and sympathetic nervous activity, mainly explained by an attenuated parasympathetic activity, might contribute to the development of insulin resistance and Type 2 diabetes.

  • 43.
    Mörner, Stellan
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Rask, Peter
    Olofsson, Bert-Ove
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Kazzam, Elsadig
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Waldenström, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Parasympathetic dysfunction in hypertrophic cardiomyopathy assessed by heart rate variability: comparison between short-term and 24-h measurements2005In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 25, no 2, p. 90-99Article in journal (Other academic)
    Abstract [en]

    In this study, we evaluate cardiac autonomic function in hypertrophic cardiomyopathy (HCM) by assessing heart rate variability (HRV), comparing a short-term laboratory method with an ambulatory (24-h) method, in patients with and without beta-blockade. Reduced HRV is a risk factor for adverse events in some cardiac diseases, but is not a proven risk indicator in HCM. Analysis of HRV has been based on either short- or long-term electrocardiographic recordings and previous studies in HCM have shown conflicting results. There is no consensus on which method to prefer, and we evaluate, for the first time, both short- and long-term analyses in patients with HCM. Long- and short-term HRV analyses were performed in 43 patients with HCM. They were divided in two groups, 22 patients on beta-blockade and 21 non-treated patients. As controls, 121 healthy subjects were used. Young patients without beta-blockade showed a reduction in HRV parameters reflecting parasympathetic function, both in the short- and long-term registrations, which was attenuated by beta-blockade. Parasympathetic autonomic regulation was found to be impaired in young patients with HCM. This may be of clinical relevance as abnormal autonomic function might be a substrate for malignant dysrhythmias. The impairment was attenuated by beta-blockade, which might indicate a clinically useful effect. We also show that short- and long-term methods yield similar results, suggesting that a short-term registration might be sufficient to assess HRV in patients with HCM.

  • 44.
    Nicoll, Rachel
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Schmermund, A.
    Cardiology, Bethanian Hospital, Frankfurt, Germany.
    Diederichsen, A.
    Cardiology, Odense University Hospital, Odense, Denmark.
    Mickley, H.
    Cardiology, Odense University Hospital, Odense, Denmark.
    Overhus, K.
    Cardiology, Odense University Hospital, Odense, Denmark.
    Zamorano, P.
    Cardiology, University Hospital Ramón y Cajal Carretera, Madrid, Spain.
    Gueret, P.
    Cardiology, Hôpital Henri Mondor Creteil, France.
    Maffi, E.
    Cardiology, Giovanni XXIII Hospital, Italy.
    Cademartiri, F.
    Cardiology, Giovanni XXIII Hospital, Italy.
    Henein, Michael
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Euro-ccad: Differing conventional atherosclerosis risk factors for coronary calcification depending on degree of luminal stenosis2014In: Atherosclerosis, ISSN 0021-9150, E-ISSN 1879-1484, Vol. 235, no 2, p. E81-E82Article in journal (Other academic)
  • 45.
    Nicoll, Rachel
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine. Ctr Heart, Umea, Sweden.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Zhao, Y.
    Diederichsen, A.
    Mickley, H.
    Ovrehus, K.
    Zamorano, P.
    Gueret, P.
    Schmermund, A.
    Maffei, E.
    Cademartiri, F.
    Budoff, M.
    Henein, M.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    The coronary calcium score is a more accurate predictor of significant coronary stenosis than conventional risk factors in symptomatic patients: Euro-CCAD study2016In: International Journal of Cardiology, ISSN 0167-5273, E-ISSN 1874-1754, Vol. 207, p. 13-19Article in journal (Refereed)
    Abstract [en]

    Aims: In this retrospective study we assessed the predictive value of the coronary calcium score for significant (>50%) stenosis relative to conventional risk factors. Methods and Results: We investigated 5515 symptomatic patients from Denmark, France, Germany, Italy, Spain and the USA. All had risk factor assessment, computed tomographic coronary angiogram (CTCA) or conventional angiography and a CT scan for coronary artery calcium (CAC) scoring. 1539 (27.9%) patients had significant stenosis, 5.50 of whom had zero CAC. In 5074 patients, multiple binary regression showed the most important predictor of significant stenosis to be male gender (B = 1.07) followed by diabetes mellitus (B = 0.70) smoking, hypercholesterolaemia, hypertension, family history of CAD and age but not obesity. When the log transformed CAC score was included, it became the most powerful predictor (B = 1.25), followed by male gender (B = 0.48), diabetes, smoking, family history and age but hypercholesterolaemia and hypertension lost significance. The CAC score is a more accurate predictor of >50% stenosis than risk factors regardless of the means of assessment of stenosis. The sensitivity of risk factors, CAC score and the combination for prediction of >50% stenosis when measured by conventional angiogram was considerably higher than when assessed by CTCA but the specificity was considerably higher when assessed by CTCA. The accuracy of CTCA for predicting >50% stenosis using the CAC score alone was higher (AUC 0.85) than using a combination of the CAC score and risk factors with conventional angiography (AUC 0.81). Conclusion: In symptomatic patients, the CAC score is a more accurate predictor of significant coronary stenosis than conventional risk factors.

  • 46.
    Nicoll, Rachel
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Zhao, Ying
    Diederichsen, A.
    Mickley, H.
    Ovrehus, K.
    Zamorano, J.
    Gueret, P.
    Schmermund, A.
    Maffei, E.
    Cademartiri, F.
    Budoff, M.
    Henein, Michael
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Gender and age effects on risk factor-based prediction of coronary artery calcium in symptomatic patients: a Euro-CCAD study2016In: Atherosclerosis, ISSN 0021-9150, E-ISSN 1879-1484, Vol. 252, p. 32-39Article in journal (Refereed)
    Abstract [en]

    Background and aims: The influence of gender and age on risk factor prediction of coronary artery calcification (CAC) presence in symptomatic patients is unclear.

    Methods: From the European Calcific Coronary Artery Disease (EURO-CCAD) cohort, we retrospectively investigated 6309 symptomatic patients, 62% male, from Denmark, France, Germany, Italy, Spain and USA. All had risk factor assessment and CT scanning for CAC scoring.

     Results: The prevalence of CAC among females was lower than among males in all age groups. Using multivariate logistic regression, age, dyslipidaemia, hypertension, diabetes and smoking were independently predictive of CAC presence in both genders. In addition to a progressive increase in CAC with age, the most important predictors of CAC presence were dyslipidaemia and diabetes (β = 0.64 and 0.63 respectively) in males and diabetes (β = 1.08) followed by smoking (β = 0.68) in females; these same risk factors were also important in predicting increasing CAC scores. There was no difference in the predictive ability of diabetes, hypertension and dyslipidaemia in either gender for CAC presence in patients aged <50 and 50-70 years. However, in patients aged >70, only dyslipidaemia predicted CAC presence in males and only smoking and diabetes were predictive in females. 

     

    Conclusion:  In symptomatic patients, there are significant differences in the ability of conventional risk factors to predict CAC presence between genders and between patients aged <70 and ≥70, indicating the important role of age in predicting CAC presence.

  • 47.
    Nicoll, Rachel
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Zhao, Ying
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Diederichsen, Axel
    Mickley, Hans
    Ovrehus, Kristian
    Zamorano, Jose
    Gueret, Pascal
    Schmermund, Axel
    Maffei, Erica
    Cademartiri, Filippo
    Budoff, Matt
    Henein, Michael
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Diabetes and male sex are key risk factor correlates of the extent of coronary artery calcification: a Euro-CCAD study2017In: Journal of diabetes and its complications, ISSN 1056-8727, E-ISSN 1873-460X, Vol. 31, no 7, p. 1096-1102Article in journal (Refereed)
    Abstract [en]

    Background and Aims: Although much has been written about the conventional cardiovascular risk factor correlates of the extent of coronary artery calcification (CAC), few studies have been carried out on symptomatic patients. This paper assesses the potential ability of risk factors to associate with an increasing CAC score. Methods: From the European Calcific Coronary Artery Disease (Euro-CCAD) cohort, we retrospectively investigated 6309 symptomatic patients, 62% male, from Denmark, France, Germany, Italy, Spain and the USA. All had conventional cardiovascular risk factor assessment and CI scanning for CAC scoring. Results: Among all patients, male sex (OR = 4.85, p < 0.001) and diabetes (OR = 236, p < 0.001) were the most important risk factors of CAC extent, with age, hypertension, dyslipidemia and smoking also showing a relationship. Among patients with CAC, age, diabetes, hypertension and dyslipidemia were associated with an increasing CAC score in males and females, with diabetes being the strongest dichotomous risk factor (p < 0.001 for both). These results were echoed in quantile regression, where diabetes was consistently the most important correlate with CAC extent in every quantile in both males and females. To a lesser extent, hypertension and dyslipidemia were also associated in the high CAC quantiles and the low CAC quantiles respectively. Conclusion: In addition to age and male sex in the total population, diabetes is the most important correlate of CAC extent in both sexes.

  • 48.
    Obayashi, K
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Hörnsten, Rolf
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Okamoto, S
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Ando, Y
    Suhr, Ole B
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Hemodynamic responses after tilt reversal in FAP2011In: Amyloid: Journal of Protein Folding Disorders, ISSN 1350-6129, E-ISSN 1744-2818, Vol. 18, no Suppl 1, p. 161-163Article in journal (Refereed)
    Abstract [en]

    The aim of the study was to evaluate hemodynamic responses after tilt reversal in familial amyloid polyneuropathy (FAP). Systolic blood pressure (BP) and heart rate variability (HRV) were analyzed in the baseline, 70-degree upright position, and after tilt reversal in 10 patients with FAP and 14 healthy controls. Maximum systolic BP after tilt reversal was increased in FAP as compared to baseline (BP overshoot), whereas controls showed a significantly lower BP overshoot. In all states, all HRV parameters were significantly lower than those of the controls. In a linear regression analysis adjusted for age, we found a significant inverse relation between BP overshoot and HRV in all three states. Five patients presented atrial arrhythmia precluding HRV analysis: four of those presented BP overshoots 12 mmHg. BP overshoot may be a useful marker to assess the progression of cardiac autonomic dysfunction, especially since heart arrhythmia in many patients with FAP prevents HRV analysis.

  • 49.
    Obayashi, Konen
    et al.
    Department of Diagnostic Medicine, Graduate School of Life Sciences, Kumamoto University, Honjo, Kumamoto, Japan.
    Hörnsten, Rolf
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Okamoto, Sadahisa
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Ando, Yukio
    Department of Diagnostic Medicine, Graduate School of Life Sciences, Kumamoto University, Honjo, Kumamoto, Japan.
    Suhr, Ole B
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Blood pressure overshoot after tilt reversal in patients with familial amyloidotic polyneuropathy2011In: Hypertension Research, ISSN 0916-9636, E-ISSN 1348-4214, Vol. 34, no 1, p. 133-138Article in journal (Refereed)
    Abstract [en]

    The pathophysiology of the hemodynamic responses to postural stress in familial amyloidotic polyneuropathy (FAP) remains to be elucidated. The aim of the study was to evaluate hemodynamic responses after tilt reversal in FAP. Systolic blood pressure (BP) and heart rate variability (HRV) were analyzed in the baseline, 70° upright position, and after tilt reversal in 15 FAP patients and 14 healthy controls. Beat-to-beat BP was recorded with a Finapres device. Maximum systolic BP after tilt reversal was increased with 22±13 mm Hg in FAP patients as compared with baseline (BP overshoot), whereas controls showed a significantly lower BP overshoot (8±6 mm Hg, P<0.001). In all states, total spectral power and the power of the low and high frequency components were all significantly lower than those of the controls (P<0.01). In a linear regression analysis adjusted for age, we found a significant inverse relation between BP overshoot and HRV (total spectral power, power of the low-frequency and high-frequency components) in all three states (standardized β between -0.74 to -0.53, P<0.01). Five FAP patients presented a trial arrhythmia precluding HRV analysis: four of those presented BP overshoots 12 mm Hg. BP overshoot may be a marker to assess the progression of cardiac autonomic dysfunction, especially as heart arrhythmia in many FAP patients prevent HRV analysis. In addition, assessment of the post-tilt BP reaction points to possible treatment modalities for orthostatic hypotension at least in the early stages of the disease.

  • 50.
    Rydberg, Annika
    et al.
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Karlsson, Markus
    Hörnsten, Rolf
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Wiklund, Urban
    Can analysis of heart rate variability predict arrhythmia in children with fontan circulation?2008In: Pediatric Cardiology, ISSN 0172-0643, E-ISSN 1432-1971, Vol. 29, no 1, p. 50-55Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to examine whether changes in heart rate variability (HRV) can predict arrhythmias in children who have undergone the Fontan procedure. The study included 15 children with total cavopulmonary connection. All examinations included echocardiography and 24-h ambulatory electrocardiogram with power spectral analysis of HRV and Poincaré plots (plots of each R-R interval as a function of the previous R-R interval). Six patients developed supraventricular tachycardia (four or more consecutive supraventricular beats). One patient was excluded from the study due to the development of bradycardia, necessitating placement of a pacemaker. Compared to the arrhythmia group, the patients without arrhythmias (n = 8) exhibited a significant difference in the standard deviation of instantaneous beat-to-beat R-R interval variability (= 0.02). Poincaré plots of patients without arrhythmias showed a typical torpedo- or comet-shaped pattern, whereas the arrhythmia group showed a more complex pattern. Although this study examined only a few subjects, needing confirmation by larger studies, it does indicate that patients who develop arrhythmias after receiving the Fontan procedure show a different Poincaré pattern compared to the nonarrhythmic group—even before the arrhythmia can be detected using the conventional Holter procedure. Routine follow-up using the Holter procedure and Poincaré plot analysis could help detect early arrhythmias.

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