umu.sePublications
Change search
Refine search result
1 - 22 of 22
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Abrahamsson, Pernilla
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Åberg, Anna-Maja
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    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.
    Waldenström, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Detection of myocardial ischaemia using surface microdialysis on the beating heart2011In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 31, no 3, p. 175-181Article in journal (Refereed)
    Abstract [en]

    Microdialysis (MD) can be used to study metabolism of the beating heart. We investigated whether microdialysis results obtained from epicardial (surface) sampling reflect acute changes in the same way as myocardial sampling from within the substance of the ventricular wall. In anaesthetized open-thorax pigs a coronary snare was placed. One microdialysis probe was placed with the sampling membrane intramyocardially (myocardial), and a second probe was placed with the sampling membrane epicardially (surface), both in the area which was made ischaemic. Ten minutes collection intervals were used for microdialysis samples. Samples from 19 pigs were analysed for lactate, glucose, pyruvate and glycerol during equilibration, baseline, ischaemia and reperfusion periods. For both probes (surface and myocardial), a total of 475 paired simultaneous samples were analysed. Results from analyses showed no differences in relative changes for glucose, lactate and glycerol during baseline, ischaemia and reperfusion. Surface microdialysis sampling is a new application of the microdialysis technique that shows promise and should be further studied.

  • 2.
    Abrahamsson, Pernilla
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Åberg, Anna-Maja
    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.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Blind, Per-Jonas
    Surface microdialysis sampling: a new approach described in a liver ischaemia model2012In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 32, no 2, p. 99-105Article in journal (Refereed)
    Abstract [en]

    We recently have shown that samples from microdialysis (MD) probes placed on the surface of the heart reflect metabolic events in the myocardium. This new interesting observation challenges us to consider whether surface application of MD applies to other parenchymatous organs and their surfaces. In 13 anesthetized pigs, transient liver ischaemia was achieved by occlusion of arterial and venous inflow to the liver. Two probes on liver surface and two in parenchyma were perfused with a flow rate of 1 mu l per min (n = 13). An identical set-up was used for probes with a flow rate of 2 mu l per min (n = 9). Samples were collected for every 15-min period during 60 min of baseline, 45 min of ischaemia and 60 min of reperfusion. Lactate, glucose, pyruvate and glycerol were analysed in MD samples. We focused on relative changes in the present study. There was a strong agreement in relative lactate and glucose levels between probes placed on liver surface and those on parenchyma. No significant differences in relative changes in lactate and glucose levels were seen between samples from surface probes and probes in liver parenchyma during equilibration, baseline, ischaemia or reperfusion with a flow rate of 1 mu l per min. MD sampling applied on the liver surface is a new application area for the MD technique and may be used to monitor liver metabolism during both physiological and pathophysiological conditions.

  • 3.
    Bajraktari, Gani
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Clinic of Cardiology, University Clinical Centre of Kosova; Medical Faculty, University of Prishtina, Prishtina, Kosovo.
    Bytyci, Ibadete
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Clinic of Cardiology, University Clinical Centre of Kosova.
    Henein, Michael Y.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Molecular & Clinical Sciences Research Institute, St George University, and Brunel University, London, UK.
    Left atrial structure and function predictors of recurrent fibrillation after catheter ablation: a systematic review and meta-analysis2019In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097XArticle in journal (Refereed)
    Abstract [en]

    Background: Catheter ablation (CA) has become a conventional treatment for atrial fibrillation (AF), but remains with high recurrence rate. The aim of this meta-analysis was to determine left atrial (LA) structure and function indices that predict recurrence of AF.

    Methods: We systematically searched PubMed-Medline, EMBASE, Scopus, Google Scholar and the Cochrane Central Registry, up to September 2017 in order to select clinical trials and observational studies which reported echocardiographic predictors of AF recurrence after CA. Eighty-five articles with a total of 16 126 patients were finally included.

    Results: The pooled analysis showed that after a follow-up period of 21 +/- 12 months, patients with AF recurrence had larger LA diameter with weighted mean difference (WMD: 2 center dot 99 ([95% CI 2 center dot 50-3 center dot 47], P<0 center dot 001), larger LA volume index (LAVI) maximal and LAVI minimal (P<0 center dot 0001 for both), larger LA area (P<0 center dot 0001), lower LA strain (P<0 center dot 0001) and lower LA total emptying fraction (LA EF) (P<0 center dot 0001) compared with those without AF recurrence. The most powerful LA predictors (in accuracy order) of AF recurrence were as follows: LA strain <19% (OR: 3 center dot 1[95% CI, -1.3-10 center dot 4], P<0 center dot 0001), followed by LA diameter >= 50 mm (OR: 2 center dot 75, [95% CI 1 center dot 66-4 center dot 56,] P<0 center dot 0001), and LAVmax >150 ml (OR: 2 center dot 25, [95% CI, 1.1-5 center dot 6], P = 0 center dot 0002).

    Conclusions: Based on this meta-analysis results, a dilated left atrium with diameter more than 50 mm and volume above 150 ml or myocardial strain below 19% reflect an unstable LA that is unlikely to hold sinus rhythm after catheter ablation for atrial fibrillation.

  • 4. Brolin, Gustav
    et al.
    Edenbrandt, Lars
    Granerus, Goeran
    Olsson, Anna
    Afzelius, David
    Gustafsson, Agneta
    Jonsson, Cathrine
    Hagerman, Jessica
    Johansson, Lena
    Riklund, Katrine
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. EQUALIS AB, Uppsala, Sweden.
    Ljungberg, Michael
    The accuracy of quantitative parameters in Tc-99m-MAG3 dynamic renography: a national audit based on virtual image data2016In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 36, no 2, p. 146-154Article in journal (Refereed)
    Abstract [en]

    Assessment of image analysis methods and computer software used in Tc-99m-MAG3 dynamic renography is important to ensure reliable study results and ultimately the best possible care for patients. In this work, we present a national multicentre study of the quantification accuracy in Tc-99m-MAG3 renography, utilizing virtual dynamic scintigraphic data obtained by Monte Carlo-simulated scintillation camera imaging of digital phantoms with time-varying activity distributions. Three digital phantom studies were distributed to the participating departments, and quantitative evaluation was performed with standard clinical software according to local routines. The differential renal function (DRF) and time to maximum renal activity (T-max) were reported by 21 of the 28 Swedish departments performing Tc-99m-MAG3 studies as of 2012. The reported DRF estimates showed a significantly lower precision for the phantom with impaired renal uptake than for the phantom with normal uptake. The T-max estimates showed a similar trend, but the difference was only significant for the right kidney. There was a significant bias in the measured DRF for all phantoms caused by different positions of the left and right kidney in the anterior-posterior direction. In conclusion, this study shows that virtual scintigraphic studies are applicable for quality assurance and that there is a considerable uncertainty associated with standard quantitative parameters in dynamic Tc-99m-MAG3 renography, especially for patients with impaired renal function.

  • 5.
    Bytyçi, Ibadete
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Universi College, Pristina, Kosovo, Albania; Clinic of Cardiology, University Clinical Centre of Kosovo, Pristina, Kosovo, Albania.
    Bajraktari, Gani
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Universi College, Pristina, Kosovo, Albania.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Henein, Michael Y.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Molecular and Clinic Research Institute, St George University, and7Brunel University, London, UK.
    Compromised left atrial function and increased size predict raised cavity pressure: a systematic review and meta-analysis2019In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 39, no 5, p. 297-307Article, review/survey (Refereed)
    Abstract [en]

    Aim: This meta-analysis assesses left atrial (LA) cavity and myocardial function measurements that predict pulmonary capillary wedge pressure (PCWP). Methods: PubMed-MEDLINE, EMBASE, Scopus, Google Scholar and the Cochrane Central Registry were searched up to December 2018 for studies on the relationship of LA diameter, LA indexed volume (LAVI max, LAVI min), peak atrial longitudinal (PALS), peak atrial contraction (PACS) strain and total emptying fraction (LAEF) with PCWP. Eighteen studies with 1343 patients were included. sensitivity and specificity (with 95% CI) for evaluation of diagnostic accuracy and the best cut-off values for different LA indices in predicting raised PCWP were estimated using summary receiver operating characteristic analysis. Results: The pooled analysis showed association between PCWP and LA diameter: Cohen's d = 0 center dot 87, LAVI max: d = 0 center dot 92 and LAVI min: d = 1 center dot 0 (P<0 center dot 001 for all). A stronger correlation was found between PCWP and PALS: d = 1 center dot 26, and PACS: d = 1 center dot 62, total EF d = 1 center dot 22 (P<0 center dot 0001 for all). PALS <= 19% had a summary sensitivity of 80% (65-90) and summary specificity of 77% (52-92), positive likelihood ratio (LR+) 3 center dot 74, negative likelihood ratio (LR-) DOR > 15 center dot 1 whereas LAVI >= 34 ml m(-2) had summary sensitivity of 75% (55-89) and summary specificity 77% (57-90), with LR+ >3, LR- 0 center dot 32 and DOR >10 center dot 1. Conclusions: Compromised LA myocardial function and increased size predict raised cavity pressure. These results should assist in optimum follow-up of patients with fluctuating LA pressure.

  • 6.
    Claesson, Jonas
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology. Anestesiologi och intensivvård.
    Lehtipalo, Stefan
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology. Anestesiologi och intensivvård.
    Bergstrand, Ulf
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology. Anestesiologi och intensivvård.
    Arnerlöv, Conny
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery. Kirurgi.
    Rocksen, David
    Hultin, Magnus
    Winsö, Ola
    Intestinal circulation, oxygenation and metabolism is not affected by oleic acid lung injury.2005In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 25, no 6, p. 357-363Article in journal (Refereed)
    Abstract [en]

    This study was performed to establish a platform for further studies on effects of ventilatory treatment modalities on the intestines during mechanical ventilation of acute lung injury (ALI). We tested the hypotheses that oleic acid (OA) infusion causes changes in intestinal circulation, oxygenation and metabolism, and that OA is distributed to tissues outside the lung. This was performed as an experimental, prospective and controlled study in an university animal research laboratory. Thirteen juvenile anaesthetized pigs were used in the main study, where seven were given an intravenous infusion of 0.1 ml kg(-1) OA and six served as control (surgery only). In a separate study, four animals were given an intravenous infusion of 0.1 ml kg(-1) (3)H-labelled OA. We measured systemic and mesenteric (portal venous blood flow, jejunal mucosal perfusion) haemodynamic parameters, mesenteric oxygenation (jejunal tissue oxygen tension) and systemic cytokines (tumour necrosis factor-alpha and interleukin-6). We calculated mesenteric lactate flux and mesenteric oxygen delivery, uptake and extraction ratio. In the animals given 3H-OA, we measured 3H-OA in different tissues (lungs, heart, liver, kidney, stomach, jejunum, colon and arterial blood). We found that OA given intravenously is distributed in small amounts to the intestines. This intestinal exposure to OA does not cause intestinal injury when evaluating mesenteric blood flow, metabolism or oxygenation. OA infusion induced a moderate increase in mean pulmonary arterial pressure and a decrease in PaO2/Fraction inspired O2 (P/F) ratio, giving evidence of severe lung injury. Consequently, the OA lung injury model is suitable for studies on intestinal effects of ventilatory treatment modalities during mechanical ventilation of ALI.

  • 7.
    Hagström, Linn
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Henein, Michael Y
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Karp, Kjell
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Waldenström, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Impact of age and sex on normal left heart structure and function2017In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 37, no 6, p. 759-766Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Accurate age- and sex-related normal reference values of ventricular structure and function are important to determine the level of dysfunction in patients. The aim of this study therefore was to document normal age range sex-related measurements of LV structural and functional measurements to serve such purpose.

    METHODS: We evaluated left ventricular structure and function in 293 healthy subjects between 20 and 90 years with equally distributed gender. Doppler echocardiography was used including measure of both systolic and diastolic functions.

    RESULTS: Due to systolic LV function, only long axis function correlated with age (r = 0·55, P<0·01) and the correlation was stronger in females. Concerning diastolic function, there was a strong age correlation in all parameters used (r = 0·40-0·74, P<0·001). Due to LV structural changes over age, females showed a larger reduction in end-diastolic volumes, but no or trivial difference in wall thickness after the age of 60 years.

    CONCLUSION: Age is associated with significant normal changes in left ventricular structure and function, which should be considered when deciding on normality. These changes are related to systemic arterial changes as well as body stature, thus reflecting overall body ageing process. Furthermore, normal cardiac ageing in females might partly explain the higher prevalence of heart failure with preserved ejection in females.

  • 8.
    Henein, Michael Y
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Grönlund, Christer
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Tossavainen, Erik
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Söderberg, Stefan
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Gonzalez, Manuel
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Right and left heart dysfunction predict mortality in pulmonary hypertension2017In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 37, no 1, p. 45-51Article in journal (Refereed)
    Abstract [en]

    In pulmonary hypertension (PH), the right heart dysfunction is a strong predictor of adverse clinical outcome, while the role of the left heart is not fully determined. The aim of this study was to identify predictors of mortality in precapillary PH including measures of both right and left heart function. We studied 34 patients (mean age 64 ± 13, range 31-82 years, 24 females) with precapillary PH, all of whom underwent detailed Doppler echocardiographic examination of the right and left heart function using conventional and speckle-tracking echocardiography. Patients were followed up for up to 8 years (mean 4·2 ± 1·9 years). At follow-up, 16 patients survived. Left ventricular (LV) filling time (P = 0·007), pulmonary artery acceleration time (P = 0·009), right atrial pressure (RAP) (P<0·001) and tricuspid regurgitation (TR) severity (P = 0·007) were worse in the deceased group. RV global longitudinal strain (GLS) (P = 0·001), RAP (P≤0·001), LV filling time (P<0·001) and TR severity (P<0·001) were the most accurate predictors, having the largest AUC (>0·65) and carried the highest risk for mortality (P<0·001 for all). The strongest predictors of mortality in precapillary PH indirectly reflect both left and right heart dysfunction including atrial structure and function disturbances. While an interaction pattern is observed, it needs to be confirmed in a larger cohort.

  • 9.
    Henein, Michael Y.
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Tossavainen, Erik
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Aroch, Roman
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Söderberg, Stefan
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Can Doppler echocardiography estimate raised pulmonary capillary wedge pressure provoked by passive leg lifting in suspected heart failure?2019In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 39, no 2, p. 128-134Article in journal (Refereed)
    Abstract [en]

    AIMS: Non-invasive estimation of left ventricular filling pressure (LVFP) during stress is important for explaining exertional symptoms in patients with heart failure (HF). The aim of this study was to evaluate ability of Doppler echocardiographic measures of elevated LVFP with passive leg lifting (PLL) in patients with suspected HF.

    METHODS: Twenty-nine patients with clinical signs of HF who underwent simultaneous Doppler echocardiography and right heart catheterization (RHC) at rest and during PLL were consecutively investigated. Seventeen patients had normal PCWP (≤15 mmHg) at rest and during PLL and 12 with normal PCWP at rest but >15 mmHg with PLL. Conventional echo and 2D strain were used to assess early diastolic blood flow velocity (E), LV strain rate during early diastole (LVSRe), left atrial SR during atrial contraction (LASRa) and myocardial tissue Doppler velocities to assess lateral e' and further calculate E/e' and E/LVSRe and their relationship with PCWP, at rest and during PLL.

    RESULTS: Resting LAVI (β = 0·45, P = 0·009) and LASRa (β = -0·51, P = 0·004) were independently related to PCWP during PLL. Also, LASRa (β = -0·77, P<0·001), E/e' (β = 0·40, P = 0·04) and E/LVSRe (β = 0·47, P = 0·021) during PLL correlated with PCWP during PLL. Multiple regression analysis identified E/LVSRe (β = 0·46, P = 0·001) and LASRa (β = -0·58, P = 0·002) during PLL as being independently associated with PCWP during PLL.

    CONCLUSION: Left atrial volume and myocardial contraction (LASRa) at rest both predict unstable LV filling pressures measured as raised PCWP when provoked by PLL. Furthermore, LASRa at PLL seems to have the strongest association to PCWP during PLL.

  • 10.
    Häggmark, Sören
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Haney, Michael F
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Jensen, Steen M
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Näslund, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    ST-segment deviations during pacing-induced increased heart rate in patients without coronary artery disease.2005In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 25, no 4, p. 246-522Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: In order to interpret ST-segment changes as an indicator of ischemia in patients with higher heart rates (HRs), the relation between ST-segment levels and HR needs to be well defined in subjects without coronary artery disease. METHODS: Eighteen patients with normal ECGs in the catheterization laboratory, after radiofrequency ablation of AV nodal re-entry tachycardia or an accessory pathway were included. Computerized online vectorcardiography (VCG) was performed during step-wise atrial pacing-induced increases in HR up to 150 beats min(-1) (bpm). The ST-vector magnitude (ST-VM) and the relative ST change vector magnitude (STC-VM) were analysed at the J point, J + 20 and J + 60 ms. RESULTS: There was no divergence in the course of ST-VM or STC-VM based on J point + 0, 20, or 60 ms during increasing HR. The STC-VM mean values increased progressively during increases in HR above 100 bpm, with an average increase in STC-VM of 15-20 microV per 10 bpm increases in HR. The ST-VM response during HR increases showed a heterogeneous and unpredictable pattern. CONCLUSION: The STC-VM increases linearly with rising HRs above 100 bpm. The STC-VM can exceed widely recognized ischemic thresholds during higher HRs in the absence of ischemia. The choice of J point time to ST-VM measurements as tested here is not important for the STC-VM relation to HR at these HR levels. Further clinical testing is needed to improve the diagnostic specificity of STC-VM measurements during increased HRs.

  • 11.
    Kesek, Milos
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Franklin, Karl A
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery. Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Sahlin, Carin
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Pulmonary Medicine.
    Lindberg, Eva
    Heart rate variability during sleep and sleep apnoea in a population based study of 387 women2009In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 29, no 4, p. 309-315Article in journal (Refereed)
    Abstract [en]

    Increased sympathetic activity during sleep has been suggested as a link between obstructive sleep apnoea syndrome and cardiovascular disease. Heart rate variability (HRV) is a measure of autonomic effect on the heart. Different parameters have been associated with sympathetic and parasympathetic activity. We have studied HRV in different sleep stages and related the HRV-pattern to sleep apnoea in a population-based sample of 387 women. We investigated the HRV-parameters standard deviation of all R-R intervals (SDNN), root of the averaged square of successive differences (RMSSD), low frequency component (LF), high frequency component (HF), ratio of low frequency component to high frequency component LF/HF and VSAI [variation in sympathetic activity between rapid eye movement (REM) and slow wave sleep, defined as LF(REM)-LF(SWS)]. The HRV-parameters were compared with the results of a full-night polysomnography. Hourly incidence of obstructive episodes was used for classifying the subjects into four apnoea-hypopnoea index (AHI)-groups (<5, > or =5 and <15, 15-30 and >30 events). Individual sleep stages were analysed by pooling all recordings. Women with high AHI had higher heart rate and LF/HF ratio. In subjects with AHI >30, LF/HF ratio however dropped to same level as with AHI <5. Subjects with high AHI had low VSAI. Levels of SDNN, LF and LF/HF ratio during REM and light sleep were similar to wakefulness. In slow wave sleep the parameters decreased. In conclusion, moderately increased prevalence of obstructive apnoeas was associated with signs of higher sympathetic activity. High AHI was however associated with a HRV-pattern suggestive of depressed sympathetic drive and lowered ability to increase it during REM.

  • 12.
    Lindqvist, Per
    et al.
    Umeå University, Faculty of Medicine, Public Health and Clinical Medicine.
    Waldenström, Anders
    Umeå University, Faculty of Medicine, Public Health and Clinical Medicine.
    Wikström, Gerhard
    Kazzam, Elsadig
    Right ventricular myocardial isovolumic relaxation time and pulmonary pressure.2006In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 26, no 1, p. 1-8Article in journal (Refereed)
    Abstract [en]

    AIMS: Non-invasive assessment of pulmonary artery systolic pressure (PASP) has several limitations. As previously described by Burstin, the right ventricular (RV) isovolumic relaxation time (IVRt) is sensitive to changes in PASP. We therefore compared RV myocardial IVRt, derived by Doppler tissue imaging (DTI), with simultaneously measured invasive PASP. METHODS AND RESULTS: Twenty-six consecutive patients (18 males, mean age 52 +/- 12 years, range 23-75) underwent a simultaneous Doppler echocardiography, including DTI, and cardiac catheterization examination for measurement of PASP and right atrial mean pressures. IVRt was measured using the myocardial velocities by pulsed DTI at both basal and mid cavity segments of the RV free wall. As diastolic time intervals are influenced by heart rate IVRt was corrected for heart rate (IVRt/RR%). A significant correlation was found between PASP and regional IVRt/RR% at both the basal (r = 0.42, P<0.05) and mid cavity segment (r = 0.71, P<0.001). Furthermore, when only patients with normal right atrial pressures (<7 mmHg) were taken into account, the correlation coefficient improved at both basal and mid cavity segments (r = 0.74, P<0.05 and r = 0.83, P<0.01). CONCLUSION: Pulsed Doppler-derived IVRt correlates well with PASP. The use of pulsed DTI for measurement of IVRt is simple, reproducible and easy to obtain. We propose this method as an additional non-invasive tool in the assessment of PASP.

  • 13. Martinsen, S.
    et al.
    Flodin, Pär
    Umeå University, Faculty of Medicine, Umeå Centre for Functional Brain Imaging (UFBI). Umeå University, Faculty of Social Sciences, Centre for Demographic and Ageing Research (CEDAR).
    Berrebi, J.
    Lofgren, M.
    Bileviciute-Ljungar, I.
    Mannerkorpi, K.
    Ingvar, M.
    Fransson, P.
    Kosek, E.
    The role of long-term physical exercise on performance and brain activation during the Stroop colour word task in fibromyalgia patients2018In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 38, no 3, p. 508-516Article in journal (Refereed)
    Abstract [en]

    The Stroop colour word test (SCWT) has been widely used to assess changes in cognitive performance such as processing speed, selective attention and the degree of automaticity. Moreover, the SCWT has proven to be a valuable tool to assess neuronal plasticity that is coupled to improvement in performance in clinical populations. In a previous study, we showed impaired cognitive processing during SCWT along with reduced task-related activations in patients with fibromyalgia. In this study, we used SCWT and functional magnetic resonance imagingFMRI to investigate the effects of a 15-week physical exercise intervention on cognitive performance, task-related cortical activation and distraction-induced analgesia (DIA) in patients with fibromyalgia and healthy controls. The exercise intervention yielded reduced fibromyalgia symptoms, improved cognitive processing and increased task-related activation of amygdala, but no effect on DIA. Our results suggest beneficial effects of physical exercise on cognitive functioning in FM.

  • 14.
    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.

  • 15.
    Nyman, Emma
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Vanoli, Davide
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Näslund, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Grönlund, Christer
    Umeå University, Faculty of Medicine, Department of Radiation Sciences.
    Inter-sonographer reproducibility of carotid ultrasound plaque detection using Mannheim consensus in subclinical atherosclerosis2019In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097XArticle in journal (Refereed)
    Abstract [en]

    Aims: To determine the inter-sonographer reproducibility of carotid ultrasound plaque detection using Mannheim consensus in a subclinical population and evaluate associations related to the reproducibility.

    Methods and results: Bilateral ultrasound screening for carotid plaques defined by Mannheim consensus was performed on 106 subclinical participants. Two different sonographers scanned the same participant, and reproducibility of plaque detection was measured by Cohens kappa. Associations with reproducibility were evaluated by comparing wall, and plaque characteristics between subjects with plaques identified in one and both scans. In general, the inter-sonographer reproducibility of plaque detection was substantial with a kappa value of 0 center dot 70 (95% CI 0 center dot 60-0 center dot 80). Plaques detected in only one scan had significantly lower plaque area and plaque thickness (6 center dot 82 mm(2) and 1 center dot 45 mm) as compared to plaques detected in both scans (11 center dot 65 mm(2) and 1 center dot 96 mm, P<0 center dot 001).

    Conclusion: Minor carotid plaques contribute to decreased reproducibility as compared to large plaques when screening for subclinical atherosclerosis using Mannheim consensus. Using an alternative plaque definition based on plaque thickness >1.5 mm and plaque area >10 mm(2) could increase the reproducibility of plaque detection in subclinical atherosclerosis.

  • 16. Sahli, David
    et al.
    Svensson, Maria
    Umeå University, Faculty of Medicine, Public Health and Clinical Medicine.
    Lidgren, Joakim
    Öjbrandt, K
    Eriksson, Jan
    Umeå University, Faculty of Medicine, Public Health and Clinical Medicine.
    Evaluation of simple non-invasive techniques for assessment of lower extremity arterial disease2005In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 25, no 3, p. 129-134Article in journal (Refereed)
  • 17.
    Shenouda, Rafik B.
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. International Cardiac Centre, Alexandria, Egypt.
    Bytyci, Ibadete
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Clinic of Cardiology, University Clinical Centre of Kosova, Prishtina, Albania.
    Sobhy, Mohammed
    Henein, Michael Y.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine. Molecular and Clinic Research Institute, St George University, London, UK; Brunel University, Uxbridge, UK.
    Reduced regional strain rate is the most accurate dysfunction in predicting culprit lesions in patients with acute coronary syndromeIn: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097XArticle in journal (Refereed)
    Abstract [en]

    Background and Aim: Predicting culprit lesions in acute coronary syndrome (ACS) could be a challenge. The aim of this study was to assess the accuracy of regional wall motion abnormalities (RWMA) using various echocardiographic techniques and ECG changes in predicting the culprit coronary lesion in a group of patients with ACS.

    Methods: In 80 consecutive patients with ACS (age 55·7 ± 9·4 years, 77% male, 15% with CCS Angina III), an echocardiographic examination of left ventricle (LV) RWMA, tissue Doppler imaging (TDI) and speckle tracking myocardial strain and strain rate (SR) were performed before intervention.

    Results: Of the 80 patients, one‐vessel stenosis (>70%) was present in 53 (66%), two‐vessel disease in 12 (15%) and multivessel disease in 15 patients (19%). About 51% of patients had hypertension, 40% diabetes and 23% dyslipidaemia. There was no relationship between individual segmental RWMA and SR. Mean regional SR, but not peak strain, correlated with culprit lesion branch: left anterior descending – LAD (r = 0·35, P = 0·005), circumflex LCx (r = 0·32, P = 0·03) and right coronary RCA (r = 0·37, P = 0·01). Only ECG changes in the LAD territory (r = 0·26, P = 0·04) correlated with the culprit lesion. SR of LAD territories ≤−0·74 was 71% sensitive and 70% specific (AUC = 0·70, CI = 0·67–0·93, P = 0·01), SR of LCx territories of ≤−0·67 was 75% sensitive and 63% specific (AUC = 0·72, CI = 0·58–0·87, P = 0·02) and SR of RCA territories ≤−0·83 was 73% sensitive and 71% specific (AUC = 0·80, CI = 0·66–0·93, P = 0·001) in predicting significant stenosis. SR was more accurate than all other techniques in predicting the culprit lesion.

    Conclusion: In ACS, mean regional speckle tracking SR is more sensitive than peak strain, TDI, ECG changes and wall motion abnormalities in detecting significant coronary artery stenosis.

  • 18. Svedenhag, Jan
    et al.
    Larsson, Thomas P.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Olsson, Arne
    Rythen Alder, Eva
    Individual reference values for 2D echocardiographic measurements. The Stockholm - Umeå Study2015In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 35, no 4, p. 275-282Article in journal (Refereed)
    Abstract [en]

    Objectives: Improved reference values for 2D echocardiographic measurements are required, even when more recent echocardiographic technology is employed. In addition, it may be preferable to individualize reference values from age, gender and body characteristics of any subject. Design: A material of 180 healthy subjects was collected and investigated, aiming for an even distribution of sex and age (from 20 to 80years of age; the Stockholm material). For atrial areas, material from another 216 healthy subjects with similar sex and age distribution was added (the Umea material). The 2D measures determined were the left and right ventricular diameters in diastole, the left ventricular diameter in systole, the thickness of septum and posterior wall, the diameters of the aortic root (sinotubular junction) and the left atrium (all in parasternal view), together with the left and right ventricular diameters in diastole and left and right atrial areas in end-systole (apical four-chamber view). The width of the inferior vena cava (from subcostal view) was also determined. Results: Confidence intervals for females and males are presented for each of these measures. Multiple linear regression analyses with age, sex and measures of body characteristics as predictors were also performed, and for eight of the 12 measurements, such equations are presented. Conclusions: It is possible to obtain more highly individualized reference values for these cardiac dimensions, which may clinically be a better way of distinguishing pathological states from normal states.

  • 19.
    van den Berg, Johannes
    et al.
    Umeå University, Faculty of Medicine, Public Health and Clinical Medicine.
    Neely, Gregory
    Wiklund, Urban
    Umeå University, Faculty of Medicine, Radiation Sciences.
    Landström, Ulf
    Heart rate variability during sedentary work and sleep in normal and sleep-deprived states2005In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 25, no 1, p. 51-57Article in journal (Refereed)
    Abstract [en]

    The possibility of using heart rate variability (HRV) as an indicator of sleepiness was investigated by analysing heart rate (HR) activity and electroencephalography (EEG) recordings from 10 individuals who performed a monotonous attention task for 120 min in both sleep-deprived and rested states. In both conditions, measurements were collected during 60 min of sleep immediately following a 120 min of non-sleep (awake phase). Although HR decreased significantly in both the rested and the sleep-deprived states during the awake phase, HR significantly changed sooner when subjects were sleep-deprived than when they were rested. No significant changes in HRV were found during the awake phase; however, HRV correlated significantly with alpha and theta power densities when rested but not when sleep-deprived. During the sleep phase, the total HRV and very low and low frequency HRV components significantly decreased approximately 40 min after sleeping in the sleep-deprived condition. These HRV components were also significantly and negatively correlated with delta power densities. HRV does not seem to be a viable indicator of sleepiness; however, HRV may be useful for determining sleep stages.

  • 20.
    Waldenström, Anders
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Ronquist, Gunnar
    Åberg, Anna-Maja
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Ahlstrom, Katarina
    Hauck, Philip
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Abrahamsson, Pernilla
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Biber, Björn
    Haney, Michael F.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Ischaemic preconditioning reduces myocardial calcium overload in coronary-occluded pig hearts shown by continuous in vivo assessment using microdialysis2012In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 32, no 2, p. 133-138Article in journal (Refereed)
    Abstract [en]

    During ischaemia, ATP depletion leads to insufficient fuelling for Na+/K+ ATPase, decreased electrochemical potential and increased influx of calcium ions. This study demonstrated a means to assess the effects of ischaemic preconditioning (IP) on the free intracellular Ca2+ pool during prolonged ischaemia. In a porcine myocardial ischaemia model, microdialysis (MD) was used for sampling of metabolic and injury markers in IP and non-IP (control) groups. 45Ca2+ was delivered in microperfusate locally to ischaemic myocardium, with distribution and uptake assessed by 45Ca2+ recovery in microdialysate. Cardiomyocytes in vitro were exposed to a Ca2+ ionophore and tested for 45Ca2+ uptake. An accentuated myocardial calcium ion influx (observed as an increased microdialysate 45Ca2+ recovery in the extracellular milieu) was noted in control pigs compared with IP pigs during ischaemia. Suspended cardiomyocytes preincubated with a Ca2+ ionophore to increase the intracellular calcium ion pool and subsequently incubated with 45Ca2+, displayed lower 45Ca2+ uptake in cells compared with control cells not exposed to the ionophore, corroborating the idea of a strong relationship between degree of intracellular calcium overload and microdialysate 45Ca2+ recovery. The ischaemic insult was differentially verified by metabolic and injury markers. We introduce an in vivo method for serial assessment of myocardial calcium overload during ischaemia, using a MD technique and 45Ca2+ inclusion. IP leads to relatively less calcium overload as assessed by this new method, and we interpret this to mean that reduction in calcium overload is an important part of the IP protective effect.

  • 21.
    Wiklund, Urban
    et al.
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Karlsson, Marcus
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Radiation Physics.
    Öström, Mats
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Surgery. Umeå University, Faculty of Medicine, Department of Community Medicine and Rehabilitation, Forensic Medicine.
    Messner, Torbjörn
    Influence of energy drinks and alcohol on post-exercise heart rate recovery and heart rate variability2009In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 29, no 1, p. 74-80Article in journal (Refereed)
    Abstract [sv]

    Background: Media have anecdotally reported that drinking energy drinks in combination with alcohol and exercise could cause sudden cardiac death. This study investigated changes in the electrocardiogram (ECG) and heart rate variability after intake of an energy drink, taken in combination with alcohol and exercise.

    Methods: Ten healthy volunteers (five men and five women aged 19–30) performed maximal bicycle ergometer exercise for 30 min after: (i) intake of 0·75 l of an energy drink mixed with alcohol; (ii) intake of energy drink; and, (iii) no intake of any drink. ECG was continuously recorded for analysis of heart rate variability and heart rate recovery.

    Results: No subject developed any clinically significant arrhythmias. Post-exercise recovery in heart rate and heart rate variability was slower after the subjects consumed energy drink and alcohol before exercise, than after exercise alone.

    Conclusion: The healthy subjects developed blunted cardiac autonomic modulation after exercising when they had consumed energy drinks mixed with alcohol. Although they did not develop any significant arrhythmia, individuals predisposed to arrhythmia by congenital or other rhythm disorders could have an increased risk for malignant cardiac arrhythmia in similar situations.

  • 22. Winter, Reidar
    et al.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Sheehan, Florence H
    Test of simulator-based assessment of psychomotor skill in transthoracic echo2018In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 38, no 6, p. 994-999Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: We developed a transthoracic echo simulator that measures technical skill in image acquisition in terms of the deviation angle between an acquired image and the anatomically correct plane for that view. We studied whether this metric reflects the clinical experience of providers.

    METHODS: Attendees at an echo course or at the annual meeting of the Swedish Heart Association were invited to test themselves on the simulator by scanning a mannequin and acquiring four views in 15 min: parasternal long axis (pLAX) in patient 1, apical four chamber and apical long axis (aLAX) in patient 2 and pLAX in patient 3. Their experience with echo was assessed from duration in years and procedure volume in the past year. Image acquisition error was assessed from the deviation angle.

    RESULTS: , P<0·001); both had similar duration of experience (9 ± 8 versus 12 ± 11 years, P = NS). The deviation angle for aLAX (55 ± 37 degrees) was higher than for any other view (P<0·00001). aLAX was the only view whose deviation angle correlated significantly with experience and only with procedure volume (r = -0·357, P = 0·008).

    CONCLUSIONS: These results demonstrate that deviation angle, a novel metric of technical skill in image acquisition, reflects clinical experience. Simulator-based testing provides objective and quantitative assessment that may be of value in the certification of trainees and for maintenance of certification.

1 - 22 of 22
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf