Influence of physical training after a myocardial infarction on left ventricular contraction mechanics

BACKGROUND: Physical exercise adds benefits improving evolution of the ischemic heart disease, enhancing individual functional capacity and preventing ventricular remodeling. In this study we investigated the impact of a program of physical training started after an uncomplicated post-acute myocardial infarction (AMI) on the mechanics of left ventricle (LV) contraction. METHODS: A total of 53 patients were included, 27 of whom were randomized to a supervised training program (TRAINING group), and 26 to a CONTROL group, who received usual orientations for physical exercise after AMI. All patients underwent cardiopulmonary stress testing and an echocardiogram with speckle tracking technique to measure several parameters of LV contraction mechanics at 1 month and 5 months after AMI. RESULTS: No significant difference in the analysis of LV longitudinal, radial and circumferential strain parameters between groups after the training period was found. After the training program, analysis of torsional mechanics demonstrated a reduction in the LV basal rotation of the TRAINING group in comparison to the CONTROL group (TRAINING, -5.9±2.3 vs CONTROL, -7.5±2.9 ; P=0.03), and in the basal rotational velocity ​​( TRAINING, -53.6±18.4 vs CONTROL, -68.8±22.1 º/s; P=0.01), twist velocity (TRAINING, 127.4±32.2 vs CONTROL, 149.9±35.9 vs º/s; P=0.02) and torsion (TRAINING, 2.4±0.4 vs CONTROL, 2.8±0.8 vs º/cm; P=0.02). CONCLUSIONS: Physical activity did not cause a significant improvement in LV longitudinal, radial and circumferential deformation parameters. However, the exercise had a significant impact on the LV torsional mechanics, composed particularly of a reduction in basal rotation, twist velocity, torsion and torsional velocity which can be interpreted as a ventricular “torsion reserve” in this population.

Left Ventricular Systolic Motion Pattern Differs Among Patients With Left Bundle Branch Block Patterns

Purpose:The study aimed to investigate left ventricular (LV) motion pattern in patients with LBBB patterns including patients with pacemaker rhythm (PM), type B Wolff-Parkinson-White syndrome (B-WPW), premature ventricular complexes originating from the right ventricular outflow tract (RVOT-PVC), and complete left bundle branch block (CLBBB).Methods: Two-dimensional speckle tracking was used to evaluate peak value and time to peak value of the LV twist, LV apex rotation, and LV base rotation in patients with PM, B-WPW, RVOT-PVC, and CLBBB with normal LV ejection fraction, and in age-matched control subjects.Results: The LV motion patterns were altered in all patients compared to the control groups. Patients with PM and CLBBB had a similar LV motion pattern with a reduced peak value of LV apex rotation and LV twist. Patients with B-WPW demonstrated the opposite trend in the reduction of LV rotation peak value, which was more dominant in the basal layer. The most impairment in the LV twist/rotation peak value was identified in patients with RVOT-PVC. Compared to the control group, the apical-basal rotation delay was prolonged in patients with CLBBB, followed by those with B-WPW, RVAP, and RVOT-PVC.Conclusion: The LV motion patterns were different among patients with different patterns of LBBB. CLBBB and PM demonstrated a reduction in LV twist/rotation that was pronounced in the apical layer, B-WPW showed a reduction in the basal layer, and RVOT-PVC in both layers. CLBBB had the most pronounced LV apical-basal rotation dyssynchrony.

Key role of left ventricular untwisting in endurance cyclists at onset of exercise

The rise in oxygen consumption during the transition from rest to exercise is faster in those who are endurance-trained than those who have sedentary lifestyles, partly due to a more efficient cardiac response. However, data regarding this acute cardiac response in trained individuals are limited to heart rate (HR), stroke volume and cardiac output. Considering this, we compared cardiac kinetics, including left ventricular (LV) strains and twist/untwist mechanics, between endurance-trained cyclists and their sedentary counterparts. Twenty young, male, trained cyclists and 23 untrained participants aged 18-25 years performed five similar constant workload exercises on a cyclo-ergometer (target HR: 130 bpm). During each session, LV myocardial diastolic and systolic linear strains, as well as torsional mechanics, were assessed using speckle-tracking echocardiography. Cardiac function was evaluated every 15s during the first minute and every 30s thereafter, until 240s. Stroke volume increased during the first 30-45s in both groups, but to a significantly greater extent in trained cyclists (31% vs 24%). Systolic parameters were similar in both groups. Transmitral peak filling velocity and peak filling rate responded faster to exercise and with greater amplitude in trained cyclists. Left ventricular filling pressure was lower in the former, while LV relaxation was greater, but only at the base of the left ventricle. Basal rotation and peak untwisting rate responded faster and to a greater extent in the cyclists. This study provides new mechanical insights into the key role of LV untwisting in the more efficient acute cardiac response of endurance-trained athletes at onset of exercise.

Left ventricular rotational mechanics in elite athletes with high dynamic component of their training - a three-dimensional speckle-tracking echocardiographic study

Funding Acknowledgements Type of funding sources: None. Introduction. In normal circumstances left ventricular (LV) apex and base rotate different directions during cardiac cycle, while LV apex rotates counterclocwise, LV base has a clockwise movement at the same time. This sort of towel-wringing-like movement is called LV twist. Three-dimensional speckle-tracking echocardiography (3DSTE) is a new, promising, easy-to-perform and reproducible modality for the evaluation of LV apical and basal rotations. Although cardiac adaptation is a known feature seen in highly trained athletes, there are conflicting results according to sport activity-related changes in LV rotational mechanics. The present study was designed to test whether differences in LV rotational mechanics could be detected in elite athletes with high dynamic, but different grade of static components of their training by 3DSTE. Methods. The subjects group comprised 80 elite sportmen, which group of athletes was further divided according to the task force classification of the American College of Cardiology considering dynamic and static components of their training. The following groups were created regarding to their physical activity: Group C1 (high dynamic/low static)(n = 13, mean age: 24.0 ± 5.1 years, Group C2 (high dynamic/moderate static)(n = 23, mean age: 24.6 ± 7.7 years) and Group C3 (high dynamic/high static)(n = 34, mean age: 22.8 ± 6.0 years). Their results were compared to 67 age- and gender-matched non-athletic healthy controls (mean age: 24.0 ± 5.1 years, 33 men). 3DSTE was used for the evaluation of LV rotational abnormalities. Results. Increased LV end-diastolic and end-systolic volumes could be detected in Groups C2 and C3 subjects as compared to controls. No changes in LV volumes and rotational mechanics could be detected in Group C1 cases. Reduced LV basal rotation was seen in Group C2 and C3 subjects compared to that of controls (-3.17 ± 2.81 degree and -2.88 ± 1.88 degree vs. -4.31 ± 1.82 degree, p < 0.05 and p < 0.05, respectively). It was accompanied with LV twist reduction in Groups C2 and C3 subjects compared to that of controls (11.3 ± 4.3 degree and 11.5 ± 4.1 degree vs. 14.0 ± 3.4 degree, p < 0.05 and p < 0.05, respectively). None of elite athletes showed absence of LV twist called as LV ‘rigid body rotation’ (LV-RBR). Conclusions. Significant LV basal rotation and twist reduction could be detected in elite athletes with high dynamic and moderate/high static components of their training.

Comparison of left ventricular rotational mechanics between term and extremely premature infants over the first week of age

ObjectiveLeft ventricle (LV) rotational mechanics is an emerging tool to characterise LV function, but warrants further evaluation in neonates. The aim of this study was to compare LV rotational mechanics between term and extremely preterm babies over the first week of age.MethodsIn this prospective study, we serially assessed LV rotational parameters in 50 term infants and compared them with a historical dataset of 50 preterm infants born <29 weeks gestation. LV basal and apical rotation, LV twist, LV twist/untwist rate and torsion were derived using two-dimensional speckle tracking echocardiography at three time points over the first week of age.ResultsThere was no change in LV twist, LV torsion, basal rotation or apical rotation in term infants over the study period (all p>0.05). LV twist and torsion were higher in preterm infants, and increased over time. In preterm infants, basal rotation evolved from anticlockwise to clockwise rotation. Apical rotation remained anticlockwise in both groups (all p>0.05). LV twist rate (LVTR) and untwist rate was higher in preterm infants and increased over the three time points (all p>0.05). There was a strong positive correlation between LV torsion and LV untwist rate (LVUTR) in the entire cohort during the third scan.ConclusionTerm infants exhibit minimal LV twist which remains unchanged over the first week of age. This is in contrast to premature infants who demonstrate increasing indices of twist, torsion, LVTR and LVUTR over the first week, likely as a compensatory mechanism for reduced LV compliance.

P333 Left ventricular rotational abnormalities in hypereosinophilic syndrome as assessed by three-dimensional speckle-tracking echocardiography

Introduction Hypereosinophilic syndrome (HES) is a very heterogeneous group of disorders with varied etiologies characterized by peripheral eosinophilia and eosinophilic tissue/end-organ damage. In the present study, the ability of a novel non-invasive clinical tool, three-dimensional speckle-tracking echocardiography (3DSTE) was investigated to reveal any change in left ventricular (LV) rotational mechanics in clinically asymptomatic HES patients without manifest organ damage as determined by conventional diagnostic methods. Methods The present study comprised 13 patients established diagnosis of HES. However, one patient with idiopathic HES has been excluded due to insufficient image quality. The remaining patient population contained 11 cases with idiopathic HES and one patient with acute T-lymphoma associated HES (mean age: 59.7 ± 13.7 years, 8 males). The control group consisted of 36 healthy volunteers (mean age: 52.9 ± 8.3 years, 23 males). All HES patients and controls underwent complete two-dimensional Doppler echocardiography and 3DSTE. Results Both LV apical rotation (4.86 ± 1.92 degree vs. 10.07 ± 3.92 degree, p &lt; 0.0001) and LV twist (8.52 ± 2.79 degree vs. 14.41 ± 4.26 degree, p &lt; 0.0001) showed significant deteriotations in most of HES patients. In 2 subjects absence of LV twist called as LV „rigid body rotation’ (RBR) was detected. One patient had 1.77 degree counterclockwise (abnormally directed) LV basal rotation and 14.29 degree counterclockwise (normally directed) LV apical rotation resulting in 12.59 degree LV apico-basal gradient. The other patient had normally directed -2.09 degree LV basal rotation and almost zero (-0.27 degree) LV apical rotation resulting in 1.82 degree LV apico-basal gradient. Conclusions Reduced LV apical rotation and twist could be demonstrated in HES. LV-RBR could be detected in some HES patients.

Determinants of myocardial function characterized by CMR-derived strain parameters in left ventricular non-compaction cardiomyopathy

Clinical presentation of left ventricular non-compaction cardiomyopathy (LVNC) can be heterogeneous from asymptomatic expression to congestive heart failure. Deformation indices assessed by cardiovascular magnetic resonance (CMR) can determine subclinical alterations of myocardial function and have been reported to be more sensitive to functional changes than ejection fraction. The objective of the present study was to investigate the determinants of myocardial deformation indices in patients with LVNC. Twenty patients with LVNC (44.7 ± 14.0 years) and twenty age- and gender-matched controls (49.1 ± 12.4 years) underwent functional CMR imaging using an ECG-triggered steady state-free-precession sequence (SSFP). Deformation indices derived with a feature tracking algorithm were calculated including end-systolic global longitudinal strain (GLS), circumferential strain (GCS), longitudinal and circumferential strain rate (SRll and SRcc). Twist and rotation were determined using an in-house developed post-processing pipeline. Global deformation indices (GLS, GCS, SRll and SRcc) were significantly lower in patients with LVNC compared to healthy controls (all, p < 0.01), especially for midventricular and apical regions. Apical rotation and twist were impaired for LVNC (p = 0.007 and p = 0.012), but basal rotation was preserved. Deformation indices of strain, strain rate and twist correlated well with parameters of the non-compacted myocardium, but not with the total myocardial mass or the thinning of the compacted myocardium, e.g. r = 0.595 between GLS and the non-compacted mass (p < 0.001). In conclusion, CMR deformation indices are reduced in patients with LVNC especially in affected midventricular and apical slices. The impairment of all strain and twist parameters correlates well with the extent of non-compacted myocardium.

Dissecting Myocardial Mechanics in Patients With Severe Aortic Stenosis: 2-Dimensional vs 3-Dimensional–Speckle Tracking Echocardiography

Background: Aortic valve stenosis (AS) commonly causes left ventricular (LV) pressure overload; thus, identifying patients with adverse remodeling/early LV dysfunction is critical. We compared 2-dimensional (2D) to 3-dimensional (3D) echocardiographic measures of LV myocardial deformation in patients with severe AS and studied the relation of LV preload and afterload (Zva) to myocardial deformation. Methods: We prospectively included 168 symptomatic patients (72±12 years) with severe AS and ejection fractions ≥50%. Strain parameters from those patients were compared with normal values found in the literature. 3D full-volume and 2D images were analyzed for global longitudinal strain (GLS), global radial strain (GRS), global circumferential strain (GCS), systolic strain rate (SRs), basal rotation (Rotmax-B), apical rotation (Rotmax-A), and peak systolic twist (Twistmax). Results: 2D–GLS and 2D–GCS decreased significantly compared with normal values (P˂.001 and P=.02, respectively); 2D Rotmax-B and Twistmax increased (P˂.001 vs normal values). Agreement between 2D–GLS and 3D–GLS by concordance correlation coefficient was 0.49 (95% CI, 0.39-0.57) in patients with AS. Both 2D– and 3D–GLS correlated with valvulo-arterial impedance (Zva) (r=0.34, P<.001; and r=0.23, P=.003, respectively). Conclusion: In patients with severe AS, GLS and GCS decreased, and basal rotation and twist increased to maintain LV ejection fraction. 2D– and 3D–GLS had a relatively fair agreement. Both 2D– and 3D–GLS correlated modestly with Zva.

Left Ventricular Systolic Function Assessed by Speckle Tracking Echocardiography in Athletes with and without Left Ventricle Hypertrophy

The aim of this study was to evaluate selected parameters of strain and rotation of the left ventricle (the basal rotation (BR) index, the basal circumferential strain (BCS) index, and the global longitudinal strain (GLS) of the left ventricle) in male athletes with physiological cardiac hypertrophy (LVH group), and athletes (non-LVH group) and non-athletes without hypertrophy (control group, CG). They were evaluated using transthoracic echocardiography and speckle tracking echocardiography before and after an incremental exercise test. The LVH group demonstrated lower BR at rest than the non-LVH group (p < 0.05) and the CG (p < 0.05). Physical effort had no effect on BR, nor was this effect different between groups (p > 0.05). There was a combined influence of LVH and physical effort on BR (F = 5.70; p < 0.05) and BCS (F = 4.97; p < 0.05), but no significant differences in BCS and GLS at rest between the groups. A higher BCS and lower GLS after exercise in the LVH group were demonstrated in comparison with the CG (p < 0.05). Left ventricular basal rotation as well as longitudinal and circumferential strains showed less of a difference between rest and after physical effort in subjects with significant myocardial hypertrophy. In conclusion, the obtained results may suggest that echocardiographic assessment of basal rotation and circumferential strain of the left ventricular can be important in predicting cardiac disorders caused by physical effort in individuals with physiological and pathological heart hypertrophy.

Impact of 24 weeks of supervised endurance versus resistance exercise training on left ventricular mechanics in healthy untrained humans

In addition to the well-known cardiac structural adaptation to exercise training, little work has examined changes in left ventricle (LV) mechanics. With new regional and global indexes available we sought to determine the effect of 24-wk endurance versus resistance training on LV mechanics. Twenty-three male subjects were randomly allocated to a 24-wk endurance or resistance training program. Pre- and posttraining two-dimensional echocardiographic images were acquired. Global LV mechanics [strain (ε)] were recorded in longitudinal, circumferential, and radial planes. Rotation was assessed at apical and basal levels. In addition, longitudinal ε-volume loops, across the cardiac cycle, were constructed from simultaneous LV ε (longitudinal and transverse strain) and volume measurements across the cardiac cycle as a novel measure of LV mechanics. Marginal differences in ε and rotation data were found between groups. After training, we found no change in global peak ε data. Peak basal rotation significantly increased after training, with changes in the endurance group (−2.2 ± 1.9° to −4.5 ± 3.3°) and the resistance group (−2.9 ± 3.0° to −3.4 ± 2.9°). LV ε-volume loops revealed a modest rightward shift in both groups. Although most global and regional indexes of LV mechanics were not significantly altered, 24 wk of intense supervised exercise training increased basal rotation. Further studies that assess LV mechanics in larger cohorts of subjects and those with cardiovascular disease and risk factors may reveal important training impacts. NEW & NOTEWORTHY This study builds on previous work by our group and presents a comprehensive assessment of cardiac mechanics after dichotomous exercise training programs. We highlight novel findings in addition to the inclusion of strain-volume loops, which shed light on subtle differences in longitudinal and transverse contribution to volume change throughout the cardiac cycle. Our findings suggest that training has an impact on basal rotation and possibly strain-volume loops.