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Gustafsson, Ulf
Publications (8 of 8) Show all publications
A'Roch, R., Gustafsson, U., Johansson, G., Poelaert, J. & Haney, M. (2012). Left ventricular strain and peak systolic velocity: responses to controlled changes in load and contractility, explored in a porcine model. Cardiovascular Ultrasound, 10(22)
Open this publication in new window or tab >>Left ventricular strain and peak systolic velocity: responses to controlled changes in load and contractility, explored in a porcine model
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2012 (English)In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 10, no 22Article in journal (Refereed) Published
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.

Keywords
Tissue velocities echocardiography; Ventricular function; Load
National Category
Physiology
Identifiers
urn:nbn:se:umu:diva-59415 (URN)10.1186/1476-7120-10-22 (DOI)1476-7120 (Electronic) 1476-7120 (Linking) (ISBN)
Note

A'roch, Roman Gustafsson, Ulf Johansson, Goran Poelaert, Jan Haney, Michael Journal article Cardiovascular ultrasound Cardiovasc Ultrasound. 2012 May 28;10(1):22.

Available from: 2012-09-13 Created: 2012-09-13 Last updated: 2018-06-08Bibliographically approved
A'Roch, R., Gustafsson, U., Poelaert, J., Johansson, G. & Haney, M. (2012). Left ventricular twist is load-dependent as shown in a large animal model with controlled cardiac load. Cardiovascular Ultrasound, 10(26)
Open this publication in new window or tab >>Left ventricular twist is load-dependent as shown in a large animal model with controlled cardiac load
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2012 (English)In: Cardiovascular Ultrasound, ISSN 1476-7120, E-ISSN 1476-7120, Vol. 10, no 26Article in journal (Refereed) Published
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.

Keywords
Echocardiography; Ventricular function; Rotation; Torsion; Load
National Category
Physiology
Identifiers
urn:nbn:se:umu:diva-59414 (URN)10.1186/1476-7120-10-26 (DOI)1476-7120 (Electronic) 1476-7120 (Linking) (ISBN)
Note

A'roch, Roman Gustafsson, Ulf Poelaert, Jan Johansson, Goran Haney, Michael Journal article Cardiovascular ultrasound Cardiovasc Ultrasound. 2012 Jun 25;10(1):26.

Available from: 2012-09-13 Created: 2012-09-13 Last updated: 2018-06-08Bibliographically approved
Gustafsson, U. (2010). Ventricular rotation and the rotation axis: a new concept in cardiac function. (Doctoral dissertation). Umeå: Umeå university
Open this publication in new window or tab >>Ventricular rotation and the rotation axis: a new concept in cardiac function
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Background: The twisting motion of the left ventricle (LV), with clockwise rotation at the base and counter clockwise rotation at the apex during systole, is a vital part of LV function. Even though LV rotation has been studied for decades, the rotation pattern has not been described in detail. By the introduction of speckle tracking echocardiography measuring rotation has become easy of access. However, the axis around which the LV rotates has never before been assessed. The aims of this thesis were to describe the rotation pattern of the LV in detail (study I), to assess RV apical rotation (study II), develop a method to assess the rotation axis (study III) and finally to study the effect of regional ischemia to the rotation pattern of the LV (study IV).

Methods: Healthy humans were examined in study I-III and the final study populations were 40 (60±14 years), 14 (62±11 years) and 39 (57±16 years) subjects, respectively. In study IV six young pigs (32-40kg) were studied. Standard echocardiographic examinations were performed. In study IV the images were recorded before and 4 minutes after occlusion of left anterior descending coronary artery (LAD). Rotation was measured in short axis images by using a speckle tracking software. By development of custom software, the rotation axis of the LV was calculated at different levels in every image frame throughout the cardiac cycle.

Results: Study I showed significant difference in rotation between basal and apical rotations, as well as significant differences between segments at basal and mid ventricular levels. The rotation pattern of the LV was associated with different phases of the cardiac cycle. Study II found significant difference in rotation between the LV and the RV. RV rotation was heterogeneous and bi-directional, creating a ´tightening belt action´ to reduce it circumference. Study III indicated that the new method could assess the rotation axis of the LV. The motion of the rotation axes in healthy humans displayed a physiological and consistent pattern. Study IV found a significant difference in the rotation pattern, between baseline and after LAD occlusion, by measuring the rotation axes, but not by conventional measurements of rotation. AV-plane displacement and wall motion score (WMS) were also significantly changed after inducing regional ischemia.

Conclusion: There are normally large regional differences in LV rotation, which can be associated anatomy, activation pattern and cardiac phases, indicating its importance to LV function. In difference to the LV, the RV did not show any functional rotation. However, its heterogeneous circumferential motion could still be of importance to RV function and may in part be the result of ventricular interaction. The rotation axis of the LV can now be assessed by development of a new method, which gives a unique view of the rotation pattern. The quality measurements and results in healthy humans indicate that it has a potential clinical implication in identifying pathological rotation. This was supported by the experimental study showing that the rotation axis was more sensitive than traditional measurements of rotation and as sensitive as AV-plane displacement and WMS in detecting regional myocardial dysfunction.

Place, publisher, year, edition, pages
Umeå: Umeå university, 2010. p. 57
Series
Umeå University medical dissertations, ISSN 0346-6612 ; 1378
Keywords
Left ventricular function, right ventricular function, rotation, twist, rotation axis, transition plane, ischemia, speckle tracking echocardiography
National Category
Cardiac and Cardiovascular Systems
Research subject
Cardiology
Identifiers
urn:nbn:se:umu:diva-37187 (URN)978-91-7459-096-8 (ISBN)
Public defence
2010-11-12, Sal B, Unod t 9, NUS, Umeå, 13:00 (English)
Opponent
Supervisors
Available from: 2010-10-23 Created: 2010-10-21 Last updated: 2018-06-08Bibliographically approved
Gustafsson, U., Lindqvist, P., Mörner, S. & Waldenström, A. (2009). Assessment of regional rotation patterns improves the understanding of the systolic and diastolic left ventricular function: an echocardiographic speckle-tracking study in healthy individuals. European Journal of Echocardiography (10), 56-61
Open this publication in new window or tab >>Assessment of regional rotation patterns improves the understanding of the systolic and diastolic left ventricular function: an echocardiographic speckle-tracking study in healthy individuals
2009 (English)In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, no 10, p. 56-61Article in journal (Refereed) Published
Abstract [en]

AIM To elucidate the complexity of left ventricular motion throughout the cardiac cycle, we studied regional rotation in detail. METHODS AND RESULTS: Regional rotation in six subdivisions of the circumference at three levels was studied by using speckle-tracking echocardiography in 40 healthy subjects. At the basal level the inferoseptal segments rotated significantly more clockwise during systole than the opposing anterolateral segments. At the papillary level the inferoseptal segments differed significantly from the anterolateral segments, where the inferoseptal segments rotated clockwise and the anterolateral segments rotated counter-clockwise. The apical level showed significant difference in regional rotation only at aortic valve opening. In early systole, untwist before the main systolic twist was seen at the basal and apical levels; however, the duration of the basal untwist was much longer than that of the apical. The diastolic phases of rotation at the basal and apical levels matched the different filling phases. CONCLUSION: Large regional differences in rotation are present at the basal and papillary levels in healthy subjects. The diastolic untwist matches the phases of both the E-wave and A-wave and seems to be related with intraventricular pressure differences, indicating that untwist plays an important role in the filling of the ventricle.

Keywords
Regional rotation; Left ventricular systolic function; Left ventricular diastolic function; Speckle-tracking echocardiography; Diastolic suction; Healthy humans
National Category
Cardiac and Cardiovascular Systems
Research subject
Cardiology
Identifiers
urn:nbn:se:umu:diva-37183 (URN)10.1093/ejechocard/jen141 (DOI)18490292 (PubMedID)
Available from: 2010-10-21 Created: 2010-10-21 Last updated: 2018-06-08Bibliographically approved
Lindqvist, P., Borgström, E., Gustafsson, U., Mörner, S. & Henein, M. Y. (2009). Asynchronous normal regional left ventricular function assessed by speckle tracking echocardiography: appearances can be deceptive. International Journal of Cardiology, 134(2), 195-200
Open this publication in new window or tab >>Asynchronous normal regional left ventricular function assessed by speckle tracking echocardiography: appearances can be deceptive
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2009 (English)In: International Journal of Cardiology, ISSN 0167-5273, E-ISSN 1874-1754, Vol. 134, no 2, p. 195-200Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Speckle tracking echocardiography (STE) is an angle independent method with high temporal resolution, which offers quantification of regional left ventricular (LV) wall motion. We studied radial and longitudinal LV wall motion by STE in healthy subjects with normal wall motion analysis (WMA) by eye-balling. MATERIALS AND METHODS: Eighteen healthy subjects were studied. We acquired parasternal short and apical long axis projections to determine the basal, mid and apical radial and longitudinal functions. At each level we measured; (I) radial and longitudinal peak displacement and displacement at aortic valve closure (AVC) and (II) the time interval from the Q-wave to the AVC and peak displacement. RESULTS: WMA indicated normal wall motion in all subjects. The mean peak radial displacement varied in different segments (range 3.9-9.8 mm) with highest values in the mid-level (6.9+/-1.5 mm), compared to basal level (5.9+/-1.0 mm, p<0.01) and apical level (5.4+/-1.0 mm, p<0.001). The time from Q-wave to AVC was 393 ms and in 89% of the analysed segments peak radial displacement occurred after AVC, thus mean peak radial displacement occurred 60 ms after AVC. The peak longitudinal amplitude was more synchronous with respect to AVC and with the highest amplitudes found in the two basal segments. CONCLUSIONS: In normal LV function, significant differences in peak displacement exist between segments at various LV levels using STE. In addition, in early diastole, significant discrepancy occurs between radial and longitudinal time of peak displacement, suggesting a shape change. Finally, while radial displacement was highest at mid-cavity level longitudinal displacement was highest at basal level.

Place, publisher, year, edition, pages
Elsevier, 2009
National Category
Cardiac and Cardiovascular Systems
Identifiers
urn:nbn:se:umu:diva-22853 (URN)10.1016/j.ijcard.2008.01.045 (DOI)18508139 (PubMedID)
Available from: 2009-05-19 Created: 2009-05-19 Last updated: 2018-06-08Bibliographically approved
Gustafsson, U., Lindqvist, P. & Waldenström, A. (2008). Apical circumferential motion of the right and the left ventricles in healthy subjects described with speckle tracking. Journal of the American Society of Echocardiography, 21(12), 1326-1330
Open this publication in new window or tab >>Apical circumferential motion of the right and the left ventricles in healthy subjects described with speckle tracking
2008 (English)In: Journal of the American Society of Echocardiography, ISSN 0894-7317, E-ISSN 1097-6795, Vol. 21, no 12, p. 1326-1330Article in journal (Refereed) Published
Abstract [en]

Background

The aim of this study was to determine whether right ventricular (RV) apical rotation could be of importance in RV function and compare this with left ventricular (LV) apical rotation.

Methods

Short-axis images at the apical level of both ventricles were simultaneously recorded in 14 healthy subjects (mean age, 62 ± 11 years).

Results

There was a significant difference in mean rotation between the two ventricles in the time interval between 50% of ejection and aortic valve closure (P < .05). At aortic valve closure, LV rotation was 10.9 ± 4.8° counterclockwise, and RV rotation was 1.1 ± 5.8° clockwise. The anterior and inferior parts of the right ventricle rotated in opposite directions toward the septum. The septal segments of both ventricles rotated inferiorly, thus likely reducing interventricular stress.

Conclusion

This study showed clear differences in apical rotation between the two ventricles. Whereas the left ventricle displayed uniform rotation, the right ventricle showed heterogeneous rotation, resulting overall in almost no rotation but in a “tightening belt” motion.

Keywords
Right ventricular function, Left ventricular function, Apical rotation, Speckle tracking, Ventricular interaction
National Category
Cardiac and Cardiovascular Systems
Research subject
Cardiology
Identifiers
urn:nbn:se:umu:diva-37184 (URN)10.1016/j.echo.2008.09.014 (DOI)19041576 (PubMedID)
Available from: 2010-10-21 Created: 2010-10-21 Last updated: 2018-06-08Bibliographically approved
Gustafsson, U., Larsson, M., Bjällmark, A., Lindqvist, P., Aroch, R., Haney, M. & Waldenström, A.The effect of acute myocardial ischemia on the rotation axis of the left ventricle.
Open this publication in new window or tab >>The effect of acute myocardial ischemia on the rotation axis of the left ventricle
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(English)Manuscript (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.

National Category
Cardiac and Cardiovascular Systems
Research subject
Cardiology
Identifiers
urn:nbn:se:umu:diva-37186 (URN)
Available from: 2010-10-21 Created: 2010-10-21 Last updated: 2018-06-08Bibliographically approved
Gustafsson, U., Larsson, M., Bjällmark, A., Lindqvist, P., Brodin, L. & Waldenström, A.The rotation axis of the left ventricle: a new concept derived from ultrasound data in healthy individuals.
Open this publication in new window or tab >>The rotation axis of the left ventricle: a new concept derived from ultrasound data in healthy individuals
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(English)Manuscript (preprint) (Other academic)
Abstract [en]

Introduction: The axis around which the left ventricle (LV) rotates has never previously been described. The aim was to develop a method to calculate the spatial motion of the rotation axis throughout the cardiac cycle.

Method: By constructing a model of the LV, based on dimensions and rotation values at the basal, mid ventricular and apical levels, a rotation axis could be calculated at each level in 39 healthy subjects. The transition plane, defined as the level without rotation, where basal and apical rotation meet was also calculated.

Results: The rotation axis was not congruent to the longitudinal axis of the LV at any time point. A significant and specific mean direction for each of the rotation axes for the majority of the tested time points displayed a physiological pattern.

Conclusion: This new method introduces a new concept in cardiac function and provides further insight into the complexity of LV mechanics.

National Category
Cardiac and Cardiovascular Systems
Research subject
Cardiology
Identifiers
urn:nbn:se:umu:diva-37185 (URN)
Available from: 2010-10-21 Created: 2010-10-21 Last updated: 2018-06-08Bibliographically approved
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