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  • 1.
    A'roch, Roman
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Left ventricular function's relation to load, experimental studies in a porcine model2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Background: Loading conditions are recognized to influence ventricular function according to the Starling relationship for length/stretch and force.  Many modern echocardiographic parameters which have been announced as describing ventricular function and contractile status, may be confounded by uncontrolled and unmeasured load.  These studies aimed to measure the relation between four differ­ent types of assessments of ventricular dysfunction and degrees of load.  Study examined the ‘myo­cardial performance index’ (MPI).  Study II examined long axis segmental mechanical dyssynchrony.  Study III examined tissue velocities, and Study IV examined ventricular twist.  All studies aimed to describe the relation of these parameters both to load and to inotropic changes.

    Methods:  In anesthetized juvenile pigs, left ventricular (LV) pressure and volume were measured continuously and their relationship (LVPVR) was analysed.  Preload alterations were brought about by inflation of a balloon tipped catheter in the inferior vena cava (IVCBO).  Inotropic interventions were brought about by either an overdose of anesthetic (combine intravenous pentobarbital and inhaled isoflurane, Study I), or beta blocker and calcium channel blocker given in combination (Stud­ies III and IV).  In one study (II), global myocardial injury and dysfunction was induced by endotoxin infusion.  MPI measurements were derived from LVPVR heart cycle intervals for isovolumic contrac­tion and relaxation as well as ejection time.  Long axis segmental dyssynchrony was derived by ana­lyzing for internal flow and time with segmental dyssynchronous segment volume change during systole, hourly before and during 3 hours of endotoxin infusion.  Myocardial tissue velocities were measured during IVCBO at control, during positive and then later negative inotropic interventions.  The same for apical and base circumferential rotational velocities by speckle tracking.  Load markers (including end-diastolic volume) were identified for each beat, and the test parameters were analysed together with load for a relation.  The test parameters were also tested during single apneic beats for a relation to inotropic interventions.

    Results: MPI demonstrated a strong and linear relationship to both preload and after-load, and this was due to changes in ejection time, and not the isovolumic intervals.  Long axis segmental dyssyn­chrony increased during each hour of endotoxin infusion and global myocardial injury.  This dysyn­chrony parameter was independent of load when tested by IVCBO. Peak systolic velocities were strongly load-independent, though not in all the inotropic situations and by all measurement axes.  Peak systolic strain was load-dependent, and not strongly related to inotropic conditions.  Peak sys­tolic LV twist and untwist were strongly load-dependent.

    Conclusions: MPI is strongly load-dependent, and can vary widely in value for the same contractile status if the load is varied.  Mechanical dyssynchrony measures are load-independen in health and also in early global endotoxin myocardial injury and dysfunction.  Peak sytole velocities are a clinically robust parameter of LV regional and global performance under changing load, though peak systolic strain seems to be load-dependent.  Left ventricular twist and untwist are load-dependent in this pig model.

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  • 2.
    A'Roch, Roman
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gustafsson, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Poelaert, Jan
    Anesthesiology, University of Brussels, Belgium.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Left ventricular strain and peak systolic velocity: responses to controlled changes in load and contractility, explored in a porcine model2012In: Cardiovascular Ultrasound, E-ISSN 1476-7120, Vol. 10, no 1, article id 22Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Tissue velocity echocardiography is increasingly used to evaluate global and regional cardiac function. Previous studies have suggested that the quantitative measurements obtained during ejection are reliable indices of contractility, though their load-sensitivity has been studied in different settings, but still remains a matter of controversy. We sought to characterize the effects of acute load change (both preload and afterload) and change in inotropic state on peak systolic velocity and strain as a measure of LV contractility.

    METHODS: Thirteen anesthetized juvenile pigs were studied, using direct measurement of left ventricular pressure and volume and transthoracic echocardiography. Transient inflation of a vena cava balloon catheter produced controlled load alterations. At least eight consecutive beats in the sequence were analyzed with tissue velocity echocardiography during the load alteration and analyzed for change in peak systolic velocities and strain during same contractile status with a controlled load alteration. Two pharmacological inotropic interventions were also included to generate several myocardial contractile conditions in each animal.

    RESULTS: Peak systolic velocities reflected the drug-induced changes in contractility in both radial and longitudinal axis. During the acute load change, the peak systolic velocities remain stable when derived from signal in the longitudinal axis and from the radial axis. The peak systolic velocity parameter demonstrated no strong relation to either load or inotropic intervention, that is, it remained unchanged when load was systematically and progressively varied (peak systolic velocity, longitudinal axis, control group beat 1- 5.72 +/- 1.36 with beat 8- 6.49 +/- 1.28 cm/sec, 95% confidence interval), with the single exception of the negative inotropic intervention group where peak systolic velocity decreased a small amount during load reduction (beat 1- 3.98 +/- 0.92 with beat 8- 2.72 +/- 0.89 cm/sec). Systolic strain, however, showed a clear degree of load-dependence.

    CONCLUSIONS: Peak systolic velocity appears to be load-independent as tested by beat-to-beat load reduction, while peak systolic strain appears to be load-dependent in this model. Peak systolic velocity, in a controlled experimental model where successive beats during load alteration are assessed, has a strong relation to contractility. Peak systolic velocity, but not peak strain rate, is largely independent of load, in this model. More study is needed to confirm this finding in the clinical setting.

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  • 3.
    A'roch, Roman
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gustafsson, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Johansson, Göran
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Poelaert, Jan
    Dept of Anesthesiology and Perioperative Medicine, University hospital of Brussels. Belgium.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Strain and peak systolic velocities: relation to load in a porcine modelManuscript (preprint) (Other academic)
    Abstract [en]

    Background:  Tissue velocity echocardiography is increasingly used to evaluate global and regional cardiac function.  Previous studies have suggested that the quantitative measurements obtained during ejection are reliable indices of contractility.  Their load-sensitivity has been studied in different settings, but still remains a matter of controversy.  We sought to characterize the effects of acute load change and change in inotropic state on peak systolic velocity and strain as a measure of LV contractility, and particularly to determine if these parameters were load-dependent.

    Methods: Thirteen anesthetised juvenile pigs were studied, using direct measurement of left ventricular (LV) pressure and volume and transthoracic echocardiography. Transient inflation of a vena cava balloon catheter produced controlled preload alterations.  At least eight consecutive beats in the preload alteration sequence were analysed with tissue velocity echocardiography (TVE) during the preload alteration and analysed for change in peak systolic velocities (PSV) and strain (e) during same contractile status with a controlled preload alteration.  Two pharmacological inotropic interventions were also included to generate several myocardial contractile conditions in each animal.

    Results: PSV reflected the drug-induced changes in contractility in both radial and longitudinal axis.  During the acute load change, the PSV remain stable when derived from signal in the longitudinal axis and from the radial axis.  The peak systolic velocity parameter demonstrated no strong relation to either load or inotropic intervention, that is, it remained unchanged when load was systematically and progressively varied.  Peak systolic strain, however, showed a clear degree of load-dependence.

    Conclusion:  Peak systolic velocity appears to be load-independent as tested by beat to beat load reduction, while peak systolic strain appears to be load-dependent in this model.  Peak systolic velocity has a strong relation to contractility, independent of load, in serial measures, in this model.  More study is needed to confirm this in the clinical setting.

  • 4.
    A'roch, Roman
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gustafsson, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Poelaert, Jan
    Dept of Anesthesiology and Perioperative Medicine, University hospital of Brussels. Belgium.
    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.
    Left ventricular twist is load-dependentManuscript (preprint) (Other academic)
    Abstract [en]

    Background: Left ventricular rotation and twist can be assessed noninvasively by speckle tracking echocardiography. We sought to characterize the effects of acute load change and change in inotropic state on rotation parameters as a measure of LV contractility.

    Methods: Seven anesthetised juvenile pigs were studied, using direct measurement of left ventricular (LV) pressure and volume and simultaneous transthoracic echocardiography. Transient inflation of an inferior vena cava balloon catheter (IVCBO) produced controlled load reduction.  First and last beats in the sequence of eight were analysed with speckle tracking (STE) during the load alteration and analysed for change in rotation/twist during controlled load alteration at same contractile status.  Two pharmacological inotropic interventions were also included to examine the same hypothesis in additionally conditions of increased and decreased myocardial contractility in each animal.

    Results: The IVCBO load change compared for first to last beat resulted in LV twist increase (11.67° ±2.65° vs. 16.17° ±3.56° respectively, p < 0.004) during the load alteration and under adrenaline stimulation LV twist increase 12.56° ±5.1° vs. 16.57° ±4.6° (p < 0.013), and though increased, didn’t reach significance in nega­tive inotropic condition.  Untwisting rate increased significantly at baseline from    -41.7°/sec ±41.6°/sec vs. -122.6°/sec ±55.8°/sec (P < 0.039) and under adrenaline stimulation untwisting rate increased  (-55.3°/sec ±3.8°/sec vs.  -111.4°/sec ±24.0°/sec (p<0.05), but did not systematically changed in negative inotropic condition.

    Conclusions: Peak systolic LV twist and peak early diastolic untwisting rate are load dependent.  Changes in LV load should be considered when interpreting  LV rotation/ twist.

  • 5.
    A'Roch, Roman
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Gustafsson, Ulf
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Cardiology.
    Poelaert, Jan
    Anesthesiology, University of Brussels, Belgium.
    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.
    Left ventricular twist is load-dependent as shown in a large animal model with controlled cardiac load2012In: Cardiovascular Ultrasound, E-ISSN 1476-7120, Vol. 10, article id 26Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Left ventricular rotation and twist can be assessed noninvasively by speckle tracking echocardiography. We sought to characterize the effects of acute load change and change in inotropic state on rotation parameters as a measure of left ventricular (LV) contractility.

    METHODS: Seven anesthetised juvenile pigs were studied, using direct measurement of left ventricular pressure and volume and simultaneous transthoracic echocardiography. Transient inflation of an inferior vena cava balloon (IVCB) catheter produced controlled load reduction. First and last beats in the sequence of eight were analysed with speckle tracking (STE) during the load alteration and analysed for change in rotation/twist during controlled load alteration at same contractile status. Two pharmacological inotropic interventions were also included to examine the same hypothesis in additionally conditions of increased and decreased myocardial contractility in each animal. Paired comparisons were made for different load states using the Wilcoxon's Signed Rank test.

    RESULTS: The inferior vena cava balloon occlusion (IVCBO) load change compared for first to last beat resulted in LV twist increase (11.67degrees +/-2.65degrees vs. 16.17degrees +/-3.56degrees respectively, p < 0.004) during the load alteration and under adrenaline stimulation LV twist increase 12.56degrees +/-5.1degrees vs. 16.57degrees +/-4.6degrees (p < 0.013), and though increased, didn't reach significance in negative inotropic condition. Untwisting rate increased significantly at baseline from 41.7degrees/s +/-41.6degrees/s vs.122.6degrees/s +/-55.8degrees/s (P < 0.039) and under adrenaline stimulation untwisting rate increased (55.3degrees/s +/-3.8degrees/s vs.111.4degrees/s +/-24.0degrees/s (p < 0.05), but did not systematically changed in negative inotropic condition.

    CONCLUSIONS: Peak systolic LV twist and peak early diastolic untwisting rate are load dependent. Differences in LV load should be included in the interpretation when serial measures of twist are compared.

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  • 6.
    A'Roch, Roman
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Steendijk, Paul
    Oldner, Anders
    Weitzberg, Eddie
    Konrad, David
    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.
    Left ventricular mechanical dyssynchrony is load independent at rest and during endotoxaemia in a porcine model2009In: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 196, no 4, p. 375-383Article in journal (Refereed)
    Abstract [en]

    AIM: In diseased or injured states, the left ventricle displays higher degrees of mechanical dyssynchrony. We aimed at assessing mechanical dyssynchrony ranges in health related to variation in load as well as during acute endotoxin-induced ventricular injury.

    METHODS: In 16 juvenile anaesthetized pigs, a five-segment conductance catheter was placed in the left ventricle as well as a balloon-tipped catheter in the inferior vena cava. Mechanical dyssynchrony during systole, including dyssynchrony time in per cent during systole and internal flow fraction during systole, were measured at rest and during controlled pre-load reduction sequences, as well as during 3 h of endotoxin infusion (0.25 microg kg(-)1 h(-1)).

    RESULTS: Systolic dyssynchrony and internal flow fraction did not change during the course of acute beat-to-beat pre-load alteration. Endotoxin-produced acute pulmonary hypertension by left ventricular dyssynchrony measures was not changed during the early peak of pulmonary hypertension. Endotoxin ventricular injury led to progressive increases in systolic mechanical segmental dyssynchrony (7.9 +/- 1.2-13.0 +/- 1.3%) and ventricular systolic internal flow fraction (7.1 +/- 2.4-16.6 +/- 2.8%), respectively for baseline and then at hour 3. There was no localization of dyssynchrony changes to segment or region in the ventricular long axis during endotoxin infusion.

    CONCLUSION: These results suggest that systolic mechanical dyssynchrony measures may be load independent in health and during acute global ventricular injury by endotoxin. More study is needed to validate ranges in health and disease for parameters of mechanical dyssynchrony.

  • 7.
    Gottfridsson, Peter
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Aroch, Roman
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Law, Lucy
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Aroch, Alexander
    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.
    Myrberg, Tomi
    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.
    Global longitudinal strain: effects by load and autonomic nervous system expression2018Conference paper (Other academic)
    Abstract [en]

    Background: Intrathoracic pressure related to breathing or positive pressure ventilatory support has effects on venous return to the heart and transmyocardial pressures. In addition, autonomic nerve system activity affects cardiac inotropy, chronotropy, and loading. Knowledge of these physiological interactions is relevant when interpreting atrial and ventricular strain results as part of heart function assessment by echocardiography in patients with ventilatory support. 

    Purpose: We aimed to assess 2-D global longitudinal strain (GLS%) for all four heart chambers (atria and ventricles) during controlled changes in intrathoracic pressure, as well as sympathetic nerve system activation. We hypothesized that GLS% is affected by both load and sympathetic tone. 

    Methods: With ethical approval and participant consent, 20 healthy volunteers (medical students) performed a controlled Valsalva manoeuvre, a mask positive pressure inspiration (CPAP) manoeuvre (25 cm H2O) and a Hand Grip manoeuvre (squeezing a rolled towel with 75% of maximum force with one hand for 2 minutes). We monitored continuous blood pressure and heart rate (using a Finapres) during the manoeuvres to make sure that the manoeuvres caused the desired physiologic effects.

    GLS% of the individual chambers were measured before and during these manoeuvres using commercially available post- processing software, from the 4-chamber view. 2 different operators measured independently the GLS% for every manoeuvre.  Paired measurement comparisons were performed (paired t test). 

    Results: Both the Valsalva maneuverer and CPAP caused reductions in GLS % in all four chambers. The Hand Grip manoeuvre did not cause any change in GLS % in any chamber.

    Conclusion: Since both CPAP and late Valsalva causes a reduction in preload, we assume that a decrease in preload causes a reduction in GLS% in the heart chambers. Both Valsalva and Handgrip manoeuvres causes a raised sympathicus tone which does not seem to affect GLS% in any chamber. (In the Hand Grip manoeuvre there was a rise in blood pressure and pulse during the manoeuvre, as a sign of increased sympathetic tone.)

    From these preliminary findings, we conclude that for healthy young individuals GLS% appears to decrease in all chambers during Valsalva and CPAP, while no change in GLS% is caused by the Hand Grip manoeuvre.

  • 8.
    Gottfridsson, Peter
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    A’Roch, Roman
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Law, Lucy
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Myrberg, Tomi
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Hultin, Magnus
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    A'Roch, Alexander
    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.
    Left atrial contraction strain and controlled preload alterations, a study in healthy individuals2022In: Cardiovascular Ultrasound, E-ISSN 1476-7120, Vol. 20, no 1, article id 8Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: In order to assess left atrial contractile function in disturbed circulatory conditions, it is necessary to have a clear understanding of how it behaves in a normal resting state with changes in loading conditions. However, currently the understanding of this relationship is incomplete. We hypothesize that in healthy individuals, left atrial contraction strain and its peak strain rate are increased or decreased by increasing or decreasing preload, respectively.

    METHODS: Controlled maneuvers used to change preload included continuous positive airway pressure by mask (CPAP 20 cmH2O) for preload decrease, and passive leg raise (15 degrees angle) for preload increase. Cardiac ultrasound 4-chamber views of the left atria and left ventricle were acquired at baseline and during maneuver. Acquired images were post processed and analyzed offline. Comparisons were made using paired t-test and means with 95% confidence interval.

    RESULTS: There were 38 participants, complete results were obtained from 23 in the CPAP maneuver and 27 in the passive leg raise maneuver. For the CPAP group, left atrial contraction strain was 11.6% (10.1 to 13.1) at baseline and 12.8% (11.0 to 14.6) during the maneuver (p = 0.16). Left atrial contraction peak strain rate was - 1.7 s- 1 (- 1.8 to - 1.5) at baseline and - 1.8 s- 1 (- 2.0 to - 1.6) during the maneuver (p = 0.29). For the passive leg raise-group, left atrial contraction strain was 10.1% (9.0 to 11.2) at baseline and 10.8% (9.4 to 12.3) during the maneuver (p = 0.28). Left atrial contraction peak strain rate was - 1.5 s- 1 (- 1.6 to - 1.4) at baseline and - 1.6 s- 1 (- 1.8 to - 1.5) during the maneuver (p = 0.29). Left atrial area, an indicator of preload, increased significantly during passive leg raise and decreased during CPAP.

    CONCLUSION: In healthy individuals, left atrial contraction strain and its peak strain rate seem to be preload-independent.

    TRIAL REGISTRATION: The study was 2018-02-19 registered at clinicaltrials.gov ( NCT03436030 ).

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  • 9.
    Gottfridsson, Peter
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Law, Lucy
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Aroch, Roman
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Myrberg, Tomi
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Hultin, Magnus
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Haney, Michael
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Left atrial contraction strain during a Valsalva manoeuvre: A study in healthy humans2023In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 43, no 3, p. 165-169Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Cardiac mechanics are influenced by loading conditions as well as sympathetic tone. Left atrial (LA) contractile function assessed by two-dimensional (2D) strain has been described in the setting of controlled preload alterations; however, studies show conflicting findings about change or direction of change. We hypothesized that the controlled preload reduction and the sympathetic nervous system activation that occurs during a standardized Valsalva manoeuvre would bring about a change in LA contraction strain.a

    METHODS: Healthy young adults of both sexes were recruited. Transthoracic echocardiographic ultrasound images were collected before and during a Valsalva manoeuvre. Standard imaging windows for LA strain assessment were used and the images were copied and stored for later offline analysis. These were assessed for adequate atrial wall visualization in 2D strain assessment. Paired comparisons were carried out using Student's T test.

    RESULT: Thirty-eight participants were included and there were 22 complete studies with paired pre- and during Valsalva manoeuvre. LA contraction strain at baseline was 10.5 ± 2.8% (standard deviation) and during the Valsalva manoeuvre 10.6 ± 4.6%, p = 0.86.

    CONCLUSION: The Valsalva manoeuvre, a combination of preload reduction and sympathetic nervous system activation, seems not to be associated with a change in LA contraction strain in healthy young individuals. LA contraction strain should be interpreted in the context of both atrial loading conditions and prevailing autonomic nervous system activity.

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  • 10. Grenander, A.
    et al.
    Bredbacka, S.
    Rydvall, A.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Aroch, R.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Edner, G.
    Koskinen, Lars-Owe D.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Olivecrona, M.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Antithrombin treatment in patients with traumatic brain injury: a pilot study2001In: J Neurosurg Anesthesiol, Vol. 13, no 1, p. 49-56Article in journal (Refereed)
    Abstract [en]

    This study will determine if early administration of antithrombin concentrate to patients with traumatic brain injury (TBI) can inhibit or significantly shorten the time of coagulopathy. The progress of brain injury monitored by computed tomographic scan (CT) was also assessed, as was the time needed for intensive care and outcome related to Glasgow outcome scale (GOS). Twenty-eight patients with isolated brain trauma verified with CT were included in either of two parallel groups. The Glasgow coma score (GCS) was mean 7.5, and median 7.0; signifying a moderate to severe traumatic brain injury but with a mortality of only 3.5%. The patients randomized to antithrombin treatment received a total of 100 U/kg BW during 24 hours. To measure hypercoagulability, soluble fibrin (SF), D-dimer (D-d), and thrombin-antithrombin complex (TAT) were assessed together with antithrombin (AT) and routine coagulation tests. Before treatment, SF, D-d, and TAT were markedly increased in both groups. Soluble fibrin and D-dimer (measured after treatment began) appeared to decrease faster in the AT group, and there was a statistically significant difference between the groups at 36 hours for SF and at 36 hours, 48 hours, and at Day 3 for D-d. Thrombin-antithrombin complex levels were very high in both groups but, surprisingly, showed no significant difference between the groups. The authors conclude that antithrombin concentrate administered to patients with severe TBI resulted in a marginal reduction of hypercoagulation. We could not detect any obvious influence by antithrombin on brain injury progress, on CT, or on outcome or time needed for intensive care.

  • 11.
    Gustafsson, Ulf
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Larsson, M
    School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden.
    Bjällmark, A
    School of Technology and Health, Royal Institute of Technology, Stockholm, Sweden.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    Aroch, Roman
    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.
    Waldenström, Anders
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Medicine.
    The effect of acute myocardial ischemia on the rotation axis of the left ventricleManuscript (preprint) (Other academic)
    Abstract [en]

    Introduction: We have developed a method to assess the axis around which the left ventricle (LV) rotates. The aim was to assess the effect of acute regional ischemia on the otation axis.

    Method: Mid‐LAD occlusion was induced in six anesthetised pigs and echocardiographic images were recorded at baseline and after LAD occlusion. The rotation axis was calculated at three different levels of the LV throughout the cardiac cycle. Results: The direction of the rotation axis was significantly changed (p<0.01) after LAD occlusion, being directed towards the ischemic area. AV‐plane displacement was significantly reduced (p<0.05) during ischemia. No significant difference in twist or otation amplitudes was found.

    Conclusion: This new method of assessing rotational function seems as sensitive as AV‐plane displacement and superior to traditional rotation and twist parameters in detecting dysfunction in acute ischemic myocardium. The rotation axis method has the advantage of potentially identifying areas with dysfunction.

  • 12.
    Haney, Michael
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    A'Roch, Roman
    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.
    Poelaert, Jan
    Biber, Björn
    Beat-to-beat change in myocardial performance index related to load2007In: Acta Anaesthesiologica Scandinavica, ISSN 0001-5172, E-ISSN 1399-6576, Vol. 51, no 5, p. 545-552Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: This study was designed to assess the relationship of the "myocardial performance index" (MPI) to the beat-by-beat change in pre-load with static or unchanged contractile status.

    METHODS: Eight anesthetized juvenile pigs were studied using direct measurement of the left ventricular pressure and volume. Transient inflation of a vena cava balloon catheter produced controlled pre-load alterations. Consecutive beats were analyzed, grouped for first, second, third, etc. during the pre-load alteration, and evaluated for the change in MPI during the same contractile status with a controlled pre-load alteration. Two pharmacologic inotropic interventions were also included to generate several myocardial conditions in each animal.

    RESULTS: MPI demonstrated a strong linear relationship to the pre-load and after-load. MPI increased progressively during decreasing end-diastolic volume, mostly related to changes in ejection time. MPI was observed at the same level for three different myocardial function conditions (all eight animals), with a different relationship between MPI and pre-load noted for each observation.

    CONCLUSIONS: MPI is strongly load dependent, and can vary widely in value for the same contractile status if the load is varied. The use of this index in critically ill patients should be limited in this respect. Further work is needed to establish the relationship of MPI to load and contractile status.

  • 13.
    Henein, Michael Y.
    et al.
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Tossavainen, Erik
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    Aroch, Roman
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Söderberg, Stefan
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Lindqvist, Per
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine. Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Clinical Physiology.
    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.

  • 14.
    Pösö, Tomi
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Kesek, Doris
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Aroch, Roman
    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.
    Morbid obesity and optimization of preoperative fluid therapy2013In: Obesity Surgery, ISSN 0960-8923, E-ISSN 1708-0428, Vol. 23, no 11, p. 1799-1805Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Preoperative venous return (VR) optimization and adequate blood volume is essential in management of morbidly obese patients (MO) in order to avoid perioperative circulatory instability. In this study, all subjects underwent a preoperative 3-week preparation by rapid-weight-loss-diet (RWL) as part of their treatment program for bariatric surgery.

    METHODS: This is a prospective, observational study of 34 morbidly obese patients consecutively scheduled for bariatric surgery at Sunderby County Hospital, Lulea, Sweden. Preoperative transthoracic echocardiography (TTE) was performed in the awake state before and after intravascular volume challenge (VC) of 6 ml colloids/kg ideal body weight (IBW). Effects of standardized VC were evaluated by TTE. Dynamic and non-dynamic echocardiographic indices for VC were studied. Volume responsiveness and level of VR before and after VC were assessed by TTE. An increase of stroke volume >/=13 % was considered as a volume responder.

    RESULTS: Twenty-nine out of 34 patients were volume responders. After VC, a majority of patients (23/34) were euvolemic, and only 2/34 were hypovolemic. Post-VC hypervolemia was observed in 9/34 of patients.

    CONCLUSIONS: The IBW-based volume challenge regime was found to be suitable for preoperative rehydration of RWL-prepared MO. Most of the patients were volume responders. Preoperative state of VR was not associated with volume responsiveness. IBW estimates and appropriate monitoring avoids potential hyperhydration in MO. For VC assessment, conventional Doppler indices were found to be more suitable compared to tissue Doppler, giving sufficient information on pressure-volume correlation of the left ventricle in morbidly obese.

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  • 15.
    Pösö, Tomi
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences.
    Kesek, Doris
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Aroch, Roman
    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.
    Rapid weight loss is associated with preoperative hypovolemia in morbidly obese patients2013In: Obesity Surgery, ISSN 0960-8923, E-ISSN 1708-0428, Vol. 23, no 3, p. 306-313Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: In morbidly obese patients (MO), adequate levels of venous return (VR) and left ventricular filling pressures (LVFP) are crucial in order to augment perioperative safety. Rapid weight loss (RWL) preparation with very low calorie diet is commonly used aiming to facilitate bariatric surgery. However, the impact of RWL on VR and LVFP is poorly studied.

    METHODS: In this prospective, controlled, single-center study, we hypothesized that RWL-prepared MO prior to bariatric surgery can be hypovolemic (i.e., low VR) and compared MO to lean controls with conventional overnight fasting. Twenty-eight morbidly obese patients were scheduled consecutively for bariatric surgery and 19 lean individuals (control group, CG) for elective general surgery. Preoperative assessment of VR, LVFP, and biventricular heart function was performed by a transthoracic echocardiography (TTE) protocol to all patients in the awake state. Assessment of VR and LVFP was made by inferior vena cava maximal diameter (IVCmax) and inferior vena cava collapsibility index- (IVCCI) derived right atrial pressure estimations.

    RESULTS: A majority of MO (71.4 %) were hypovolemic vs. 15.8 % of lean controls (p < 0.001, odds ratio = 13.3). IVCmax was shorter in MO than in CG (p < 0.001). IVCCI was higher in MO (62.1 +/- 23 %) vs. controls (42.6 +/- 20.8; p < 0.001). Even left atrium anterior-posterior diameter was shorter in MO compared to CG.

    CONCLUSIONS: Preoperative RWL may induce hypovolemia in morbidly obese patients. Hypovolemia in MO was more common vs. lean controls. TTE is a rapid and feasible tool for assessment of preload even in morbid obesity.

  • 16.
    Pösö, Tomi
    et al.
    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.
    Aroch, Roman
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Kesek, Doris
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Perioperative fluid guidance with transthoracic echocardiography and pulse-contour device in morbidly obese patients2014In: Obesity Surgery, ISSN 0960-8923, E-ISSN 1708-0428, Vol. 24, no 12, p. 2117-2125Article in journal (Refereed)
    Abstract [en]

    Background

    In bariatric surgery, non-or mini-invasive modalities for cardiovascular monitoring are addressed to meet individual variability in hydration needs. The aim of the study was to compare conventional monitoring to an individualized goal-directed therapy (IGDT) regarding the need of perioperative fluids and cardiovascular stability. 

    Methods

    Fifty morbidly obese patients were consecutively scheduled for laparoscopic bariatric surgery (ClinicalTrials.gov Identifier: NCT01873183). The intervention group (IG, n=30) was investigated preoperatively with transthoracic echocardiography (TTE) and rehydrated with colloid fluids if a low level of venous return was detected. During surgery, IGDT was continued with a pulse-contour device (FloTrac (TM)). In the control group (CG, n=20), conventional monitoring was conducted. The type and amount of perioperative fluids infused, vasoactive/inotropic drugs administered, and blood pressure levels were registered. 

    Results

    In the IG, 213 +/- 204 mL colloid fluids were administered as preoperative rehydration vs. no preoperative fluids in the CG (p<0.001). During surgery, there was no difference in the fluids administered between the groups. Mean arterial blood pressures were higher in the IG vs. the CG both after induction of anesthesia and during surgery (p=0.001 and p=0.001). 

    Conclusions

    In morbidly obese patients suspected of being hypovolemic, increased cardiovascular stability may be reached by preoperative rehydration. The management of rehydration should be individualized. Additional invasive monitoring does not appear to have any effect on outcomes in obesity surgery.

  • 17.
    Stenberg, Ylva
    et al.
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Rhodin, Ylva
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Lindberg, Anne
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine, Section of Medicine.
    Aroch, Roman
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Hultin, Magnus
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Wallden, Jakob
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology.
    Myrberg, Tomi
    Umeå University, Faculty of Medicine, Department of Surgical and Perioperative Sciences, Anaesthesiology. Department of Anaesthesiology and Critical Care, Sunderby Hospital, Luleå, Sweden.
    Pre-operative point-of-care assessment of left ventricular diastolic dysfunction, an observational study2022In: BMC Anesthesiology, ISSN 1471-2253, E-ISSN 1471-2253, Vol. 22, no 1, article id 96Article in journal (Refereed)
    Abstract [en]

    Background: Left ventricular (LV) diastolic dysfunction is an acknowledged peri-operative risk factor that should be identified before surgery. This study aimed to evaluate a simplified echocardiographic method using e’ and E/e’ for identification and grading of diastolic dysfunction pre-operatively.

    Methods: Ninety six ambulatory surgical patients were consecutively included to this prospective observational study. Pre-operative transthoracic echocardiography was conducted prior to surgery, and diagnosis of LV diastolic dysfunction was established by comprehensive and simplified assessment, and the results were compared. The accuracy of e’-velocities in order to discriminate patients with diastolic dysfunction was established by calculating accuracy, efficiency, positive (PPV) and negative predictive (NPV) values, and area under the receiver operating characteristic curve (AUROC).

    Results: Comprehensive assessment established diastolic dysfunction in 77% (74/96) of patients. Of these, 22/74 was categorized as mild dysfunction, 43/74 as moderate dysfunction and 9/74 as severe dysfunction. Using the simplified method with e’ and E/e’, diastolic dysfunction was established in 70.8% (68/96) of patients. Of these, 8/68 was categorized as mild dysfunction, 36/68 as moderate dysfunction and 24/68 as severe dysfunction. To discriminate diastolic dysfunction of any grade, e’-velocities (mean < 9 cm s− 1) had an AUROC of 0.901 (95%CI 0.840–0.962), with a PPV of 55.2%, a NPV of 90.9% and a test efficiency of 0.78.

    Conclusions: The results of this study indicate that a simplified approach with tissue Doppler e’-velocities may be used to rule out patients with diastolic dysfunction pre-operatively, but together with E/e’ ratio the severity of diastolic dysfunction may be overestimated.

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