Changes In Left Ventricular Shape Research Articles

Timing of Surgery for Asymptomatic Primary Mitral Regurgitation: Possible Value of Early, Serial Measurements of Left Ventricular Sphericity.

Asymptomatic primary mitral regurgitation due to myxomatous degeneration of the mitral valve leaflets may remain so for long periods, even as left ventricular function progresses to a decompensated stage. During the early compensated stage, the ventricle's initial response to the volume overload is an asymmetric increase in the diastolic short axis dimension, accomplished by a diastolic shift of the interventricular septum into the right ventricular cavity, creating a more spherical left ventricular diastolic shape, increasing diastolic filling and stroke volume. Early valve repair is recommended to reduce postoperative left ventricular dysfunction. Early serial measurements of left ventricular sphericity index [LV-Si]. during the compensated stage of mitral regurgitation might identify subtle changes in left ventricular shape and assist in determining the optimal earliest timing for surgical intervention.

Changes in left ventricular shape and morphology in the presence of heart failure: a four-dimensional quantitative and qualitative analysis.

The presence and progression of heart failure (HF) are associated with cardiac remodelling, defined as cellular, molecular and interstitial changes which occur after injury and manifest as changes in left ventricular (LV) size, mass, geometry and function. This research study was designed to investigate the changes to LV morphology and shape which occur in the presence of heart failure using three-dimensional (3D) modelling and analysis of cardiac-gated CT scans from both healthy individuals and patients classified with HF. A number of quantitative and qualitative strategies were applied to cardiac CT scans of HF patients and healthy controls (n = 7) in order to analyse changes to LV size, shape and structure and to examine LV remodelling in the different classes of HF. Three-dimensional wireframe representations of endocardial and epicardial borders were created, three-dimensional computer stereolithography models of the inner LV cavity and myocardial wall segments were generated and three-dimensionally printed and a number of clinical LV dimension and shape indices were measured. All data were analysed using one-way ANOVA with post hoc Tukey method for multiple comparisons for significant variables. Results of most significance included abnormalities in LV mass and end-systolic dimensions and significantly increased septal wall thickness among mid-range ejection fraction cases. Also of importance were significant increases in both dimension-based and volumetric sphericity index measures in all HF cases. Three-dimensional printed models provided qualitative information as to changes in inner LV cavity and myocardial wall morphology across the cardiac cycle for healthy and HF cases and validated quantitative findings. Findings from this study can successfully be applied to motivate the research and development of new HF treatment strategies and devices as well as for the development of a realistic cardiac simulator system.

Characterisation of Left Ventricular Shape Change as Defined by Sphericity Index in Patients with Acute Phase Takotsubo Cardiomyopathy and Anterior STEMI Patients

Background: Left ventricle (LV) shape changes have been proposed to be predictive of cardiovascular outcomes. Extreme sphericity has been shown to be a strong predictor of heart failure and atrial fibrillation. Sphericity index (SI) is a measure that may be used to quantify LV shape changes. The aim of our study was to characterise LV shape changes using SI between patients with acute phase Takotsubo's cardiomyopathy (TTC) and acute anterior transmural infarction (AMI). Methods: Consecutive TTC (n = 49) and AMI (n = 51) patients with a comprehensive transthoracic echocardiogram during index admission were examined. Standard measures of LV size and systolic function were compared between groups. Mean SI was calculated as an average of the ratio of the short-axis length to the long-axis length in 4- and 2-chamber apical views in both end-diastole (ED) and end-systole (ES). Both groups were also compared to healthy controls (n = 50) and dilated cardiomyopathy (DCM) controls (n = 39). Results: TTC and AMI patients had significantly worse LVEF and greater SI compared to normal controls suggesting LV shape change but not to the degree of DCM patients. Interestingly, there was no significant difference in LVEF between TTC (51 ± 12%) and AMI (53 ± 13%) [p = 0.52] but there was a significant difference in mean SI for TTC (0.60 ± 0.06) vs AMI (0.52 ± 0.07) [p < 0.0005] reflecting a more spherical shaped ventricle in the TTC group. Conclusions: Our results demonstrate differences in LV shape between different cardiac pathologies. Characterisation of these LV geometric changes may provide mechanistic insights into these underlying cardiac pathologies and guide management strategies.

Usefulness of three-dimensional spherical index to assess different types of left ventricular remodeling: A meta-analysis.

Background:Left ventricular (LV) remodeling after myocardial injury, volume or pressure overload is characterized by a change in LV shape from an ellipse to more of a sphere. The usefulness of 3-dimensional (3D) sphericity index (SpI) for accurate evaluation of LV remodeling remains uncertain despite extensive research.Methods:We searched Pubmed, Embase, Web of Science, and Cochrane databases to identify relevant studies from January 1, 1990 to August 1, 2016. The quality of each study was evaluated using the Newcastle-Ottawa Scale. Meta regression and sensitivity and subgroup analyses based on patterns of LV remodeling were performed.Results:Thirteen studies with a total of 1064 patients were included in this meta-analysis. There was evidence of obvious heterogeneity (I2 = 82.4%; P < .001), which was mainly accounted for by the pattern of remodeling according to meta-regression. The result of subgroup meta-analyses suggested that SpI in patients with eccentric remodeling was significantly higher compared with control group (95% confidence interval [CI], 0.78–1.10). No statistic difference was found in LV SpI between healthy controls and patients with concentric hypertrophy (95% CI, −0.89 to 0.16) or myocardial injury (95% CI, −0.13 to 0.41).Conclusion:3D SpI can be widely used to assess LV remodeling in patients with eccentric remodeling, but has limitations in predicting concentric hypertrophy and regional or chronic myocardial injury.

Effects of Surgical Ventricular Restoration on Left Ventricular Shape, Size, and Function for Left Ventricular Anterior Aneurysm.

Background:Surgical ventricular restoration (SVR) has been performed to treat left ventricular (LV) aneurysm. However, there is limited analysis of changes in LV shape. This study aimed to evaluate the changes in LV shape induced by SVR and the effects of SVR on LV size and function for LV aneurysm.Methods:Between April 2006 and March 2015, 18 patients with dyskinetic (dyskinetic group) and 12 patients with akinetic (akinetic group) postinfarction LV anterior aneurysm receiving SVR with the Dor procedure at Chinese People's Liberation Army General Hospital were enrolled in this study. A retrospective analysis was carried out using data from the echocardiography database. LV shape was analyzed by calculating the apical conicity index (ACI). LV end-diastolic volume index, end-systolic volume index, and ejection fraction (EF) were measured. One-way analysis of variance was used to compare means at different time points within each group.Results:Within one week after SVR, LV shape became more conical in the two groups (ACI decreased from 0.84 ± 0.13 to 0.69 ± 0.11 [t = 5.155, P = 0.000] in dyskinetic group and from 0.73 ± 0.07 to 0.60 ± 0.11 [t = 2.701, P = 0.026] in akinetic group; LV volumes were decreased significantly and became closer to normal values and EF was improved significantly in the two groups). On follow-up at least one year, LV shape remained unchanged in dyskinetic group (ACI increased from 0.69 ± 0.11 to 0.74 ± 0.12, t = −1.109, P = 0.294), but became more spherical in akinetic group (ACI significantly increased from 0.60 ± 0.11 to 0.75 ± 0.11, t = −1.880, P = 0.047); LV volumes remained unchanged in dyskinetic group, but increased significantly in akinetic group and EF remained unchanged in the two groups.Conclusions:SVR could reshape LV to a more conical shape and a more normal size and improve LV function significantly early after the procedure in patients with dyskinetic or akinetic postinfarction LV anterior aneurysm. However, LV tends to be more spherical and enlarged in the akinetic group on at least 1-year follow-up.

Invited Commentary

Undersizing mitral annuloplasty (UMA) has emerged as a mitral repair technique of choice to correct ischemic mitral regurgitation (IMR). Despite the unphysiological leaflet coaptation that results from this repair and the potential deleterious impact that restricting mitral annular dynamics and basal myocardial contraction may have on left ventricular function, extensive surgical experience with UMA and its procedural ease makes this a procedure of choice. However, to achieve better long-term patient outcomes after UMA, the adverse impact of UMA on the valve and the ventricle needs to be better understood. In this study, Pantoja and colleagues [1Pantoja J.L. Morgan A.E. Grossi E.A. et al.Undersized mitral annuloplasty increases strain in the proximal lateral left ventricular wall.Ann Thorac Surg. 2017; 103: 820-827Abstract Full Text Full Text PDF PubMed Scopus (5) Google Scholar] use a finite element model of an IMR-like left ventricle to demonstrate that UMA impacts basal myocardial mechanics and acutely alters left ventricular shape. Specifically, the end-diastolic longitudinal strain in the lateral left ventricular wall was elevated when compared with the preoperative configuration, but the fiber strain in the same region was decreased. The authors conclude that UMA induced changes in left ventricular shape and that mechanics can trigger continued remodeling of the ventricle and result in recurrent IMR and poor ventricular function. This is a nicely done computational study, albeit with some limitations, which follow:1.Preannuloplasty annular size and shape—in the clinical scenario, the mitral annular sizes, shapes, and extent of dilatation differs significantly between patients, and the effect of an annuloplasty ring on each annulus may be variable. Despite using 5 sheep-specific models in this study, the variability in annular geometry and its impact on postannuloplasty strains were not investigated.2.Impact of IMR correction—Annuloplasty acutely abolishes IMR and thus reduces. Reduced end-diastolic strain may reduce the impact that the ring may have on the ventricular shape and mechanics. The computational model does not consider the physiological effects of the ring on the ventricle.3.The distinction of the myocardium into layers is only hypothetical and not ultrastructure driven in this model. Specifically, the infarcted myocardium is thinned, lacks distinct layers, and is often stiffened from fibrosis. The computational model did not seem to consider these regional structural features, which may have an impact on the reported strains. Notwithstanding these limitations, this study provides some preliminary insights into the deleterious impact that undersizing annuloplasty may have on the left ventricle. However, whether it causes continued left ventricular remodeling or impairs systolic function remains speculative at best and needs careful experimental validation. In 2012, Shudo and coworkers [2Shudo Y. Nakatani S. Sakaguchi T. et al.Left ventricular mechanics following restrictive mitral annuloplasty for functional mitral regurgitation: two dimensional speckle tracking echocardiographic study.Echocardiography. 2012; 29: 445-450Crossref PubMed Scopus (4) Google Scholar] investigated left ventricular mechanics at 4 weeks after UMA in patients with IMR and reported that ejection fraction and longitudinal strains were largely unaltered. Radial and longitudinal strains were improved at the mid and apical levels but were unaltered at the base of the ventricle. Left ventricular twist was significantly elevated in these patients after UMA, compared with their preoperative measurements. The discrepancy between such improved left ventricular mechanics in patients who underwent UMA and the adverse impact suggested in this simplified computational model will need to be explained for clinical translation of these findings. Undersized Mitral Annuloplasty Increases Strain in the Proximal Lateral Left Ventricular WallThe Annals of Thoracic SurgeryVol. 103Issue 3PreviewRecurrence of mitral regurgitation (MR) after undersized mitral annuloplasty (MA) for ischemic MR is as high as 60%, with the recurrence rate likely due to continued dilation of the left ventricle (LV). To better understand the causes of recurrent MR, we studied the effect of undersized MA on strain in the LV wall. We hypothesize that the acute change in ventricular shape induced by MA will cause increased strain in regions nearest the mitral valve. Full-Text PDF

Depleted Leukocyte Mitochondrial DNA Copy Number Correlates With Unfavorable Left Ventricular Volumetric and Spherical Shape Remodeling in Acute Myocardial Infarction After Primary Angioplasty.

Left ventricular (LV) shape influences LV systolic function. It is possible to assess LV shape using 3-D echocardiography sphericity index (SI). Maintaining mitochondrial DNA copy number (MCN) is important for preserving mitochondrial function and LV systolic function after acute myocardial infarction (AMI). Information is limited, however, regarding the relationship between leukocyte MCN and the subsequent change in LV shape after AMI.Methods and Results:Fifty-five AMI patients undergoing primary angioplasty were recruited. Plasma MCN was measured before primary angioplasty using quantitative polymerase chain reaction. 3-D echocardiography measurement of SI was performed at baseline, and at 1-, 3-, and 6-month follow-up. AMI subjects with MCN lower than the median had a higher 6-month SI and LV volume compared with those with higher MCN. Baseline echocardiographic parameters were similar between the 2 groups. MCN was negatively correlated with 3- and 6-month SI, and 3- and 6-month LV volume. On multiple linear regression analysis, baseline plasma MCN could predict LV SI and LV volume at 6 months after primary angioplasty for AMI, even after adjusting for traditional prognostic factors. In AMI patients, higher plasma leukocyte MCN at baseline was associated with favorable LV shape and remodeling at 6-month follow-up. Plasma leukocyte MCN may provide a novel prognostic biomarker for LV remodeling after AMI.

Information maximizing component analysis of left ventricular remodeling due to myocardial infarction.

BackgroundAlthough adverse left ventricular shape changes (remodeling) after myocardial infarction (MI) are predictive of morbidity and mortality, current clinical assessment is limited to simple mass and volume measures, or dimension ratios such as length to width ratio. We hypothesized that information maximizing component analysis (IMCA), a supervised feature extraction method, can provide more efficient and sensitive indices of overall remodeling.MethodsIMCA was compared to linear discriminant analysis (LDA), both supervised methods, to extract the most discriminatory global shape changes associated with remodeling after MI. Finite element shape models from 300 patients with myocardial infarction from the DETERMINE study (age 31–86, mean age 63, 20 % women) were compared with 1991 asymptomatic cases from the MESA study (age 44–84, mean age 62, 52 % women) available from the Cardiac Atlas Project. IMCA and LDA were each used to identify a single mode of global remodeling best discriminating the two groups. Logistic regression was employed to determine the association between the remodeling index and MI. Goodness-of-fit results were compared against a baseline logistic model comprising standard clinical indices.ResultsA single IMCA mode simultaneously describing end-diastolic and end-systolic shapes achieved best results (lowest Deviance, Akaike information criterion and Bayesian information criterion, and the largest area under the receiver-operating-characteristic curve). This mode provided a continuous scale where remodeling can be quantified and visualized, showing that MI patients tend to present larger size and more spherical shape, more bulging of the apex, and thinner wall thickness.ConclusionsIMCA enables better characterization of global remodeling than LDA, and can be used to quantify progression of disease and the effect of treatment. These data and results are available from the Cardiac Atlas Project (http://www.cardiacatlas.org).

A New 4D Trajectory-Based Approach Unveils Abnormal LV Revolution Dynamics in Hypertrophic Cardiomyopathy

The assessment of left ventricular shape changes during cardiac revolution may be a new step in clinical cardiology to ease early diagnosis and treatment. To quantify these changes, only point registration was adopted and neither Generalized Procrustes Analysis nor Principal Component Analysis were applied as we did previously to study a group of healthy subjects. Here, we extend to patients affected by hypertrophic cardiomyopathy the original approach and preliminarily include genotype positive/phenotype negative individuals to explore the potential that incumbent pathology might also be detected. Using 3D Speckle Tracking Echocardiography, we recorded left ventricular shape of 48 healthy subjects, 24 patients affected by hypertrophic cardiomyopathy and 3 genotype positive/phenotype negative individuals. We then applied Generalized Procrustes Analysis and Principal Component Analysis and inter-individual differences were cleaned by Parallel Transport performed on the tangent space, along the horizontal geodesic, between the per-subject consensuses and the grand mean. Endocardial and epicardial layers were evaluated separately, different from many ecocardiographic applications. Under a common Principal Component Analysis, we then evaluated left ventricle morphological changes (at both layers) explained by first Principal Component scores. Trajectories’ shape and orientation were investigated and contrasted. Logistic regression and Receiver Operating Characteristic curves were used to compare these morphometric indicators with traditional 3D Speckle Tracking Echocardiography global parameters. Geometric morphometrics indicators performed better than 3D Speckle Tracking Echocardiography global parameters in recognizing pathology both in systole and diastole. Genotype positive/phenotype negative individuals clustered with patients affected by hypertrophic cardiomyopathy during diastole, suggesting that incumbent pathology may indeed be foreseen by these methods. Left ventricle deformation in patients affected by hypertrophic cardiomyopathy compared to healthy subjects may be assessed by modern shape analysis better than by traditional 3D Speckle Tracking Echocardiography global parameters. Hypertrophic cardiomyopathy pathophysiology was unveiled in a new manner whereby also diastolic phase abnormalities are evident which is more difficult to investigate by traditional ecocardiographic techniques.

Abstract 17790: Can 3D Echocardiography Play a Role in Left Ventricular Assist Device Optimization?

Introduction: Left ventricular (LV) assist device (LVAD) has emerged as a valuable option for patients with severe congestive heart failure both as bridge to transplantation or destination therapy. Speed optimization of LVAD is currently based on the position of the inter-ventricular septum, mitral regurgitation severity and aortic valve opening. Hypothesis: We hypothesized that 3D transthoracic echocardiography (3DE) would provide additional information on left and right ventricular (RV) volumes and shape, which could be valuable in determining optimal LVAD speed. Our aim was to assess the feasibility of combined 3D LV and RV analysis during an incremental RAMP study. Methods: Six consecutive patients undergoing a RAMP test were studied. Device speed was increased from 8000 to 12000 rpm in 400-rpm increments for axial-flow pumps (n=2) and from 2300 to 3200 rpm in 100 rpm increments for centrifugal-flow pumps (n=4). Transthoracic 3DE apical full-volume datasets of the LV and the RV were acquired (Philips) at every other step. RV and LV endocardial surfaces were reconstructed using commercial software (TomTec) and used to calculate ventricular volumes. Custom software was used to calculate LV shape indices of sphericity and conicity (a perfectly spherical/conical ventricle would result in 1.0 value). Results: Data acquisition and post-processing was feasible in 5/6 patients. In axial pumps (Figure), increments in LVAD speed were associated with gradually decreasing LV volume, while RV volume initially decreased to a minimum and then increased at higher speeds. These volumetric changes were associated with alterations in LV shape, with the LV becoming less spherical and more conical at higher speeds. With centrifugal pumps, increased speed was associated with similar changes in LV shape but with minimal changes in volumes. Conclusions: Acquisition of 3D datasets during RAMP studies is feasible and could become a valuable aid in optimizing LVAD pump speed.

Recurrent Ischaemic Mitral Regurgitation Post Mitral Annuloplasty due to Suture Dehiscence Evaluated Using Real Time Three Dimensional Transoesophageal Echocardiography

Ischaemic mitral regurgitation after myocardial infarction results from geometric changes in left ventricular shape and displacement of papillary muscles with resultant tethering and incomplete leaflet coaptation of mitral leaflets. Post mitral valve repair, both valve apparatus related factors such as persistent leaflet tethering and progressive left ventricular adverse remodelling and procedure related factors such as ring dehiscence are important causes of recurrent mitral regurgitation after initial undersized mitral ring annuloplasty. Three-dimensional echocardiography is a novel clinical tool that has the potential to provide additional anatomical and functional information regarding the mechanism of recurrent mitral regurgitation post mitral valve repair that is complementary to standard two dimensional transoesophageal echocardiography thus helping guide the most appropriate subsequent therapeutic intervention.

Implications of Acute Left Ventricular Remodeling during Squatting Stress Echocardiography

We previously demonstrated that squatting induces left ventricular (LV) wall motion abnormalities (WMA) in areas subtended by stenotic coronary arteries. In addition, it was observed that some subjects developed acute changes in LV shape (acute left ventricular remodeling [ALVRM]) during squatting. This study tested the hypothesis that patients with ALVRM during squatting echocardiography have higher incidences of severe coronary artery disease (CAD). Echocardiography was performed in all standard views during standing and squatting. End-systolic frames in the apical four-chamber view were analyzed. The subjects were divided into three groups. Group 1 consisted of 12 subjects who developed squatting-induced ALVRM with apical and distal posterior septal akinesis, dilation of the apex and marked LV shape change at end-systole. Group 2 consisted of 20 subjects with distal posterior septal and apical akinesis without ALVRM, during squatting. Group 3 consisted of 64 subjects who developed WMA in areas other than the apex (n = 49), or normal wall motion (n = 15) during squatting. Coronary angiography in group 1 revealed that 6 subjects had left main coronary artery stenosis (LMCAS ≥ 50%), two had severe three vessel disease (≥ 90% stenosis), and one had 100% left anterior descending coronary artery occlusion. Severe CAD was defined for purpose of this study as the presence of LMCAS, or severe three vessel disease (≥ 90% stenosis). Six subjects in group 2 had LMCAS and none had severe three vessel disease (P < 0.05 vs. group 1 for LMCAS and/or three vessel disease). In group 3, eight had LMCAS and none had severe three vessel disease (P < 0.0001 vs. group 1). Patients with ALVRM have severe CAD. Therefore, patients who develop ALVRM during squatting require urgent evaluation for revascularization therapy.

Marathon Rat

Cardiac adaptation to intensive exercise has long intrigued cardiologists and physiologists, particularly in relation to the notion that different types of exercise drive divergent remodeling. On the basis of a meta-analysis of 59 echocardiographic studies (including 1451 male athletes 18 to 40 years of age), Pluim et al1 concluded that endurance-trained runners, who are known to develop eccentric cardiac hypertrophy, demonstrated a more pronounced left ventricular (LV) wall thickening than expected. Strength-trained sportsmen showed an unanticipated increase in LV internal diameter besides concentric cardiac hypertrophy. These adaptations accounted for a higher LV mass, whereas no differences were found between athletes and nonathletes regarding LV ejection fraction, fractional shortening, and early and late ventricular filling velocity ratio. Recently, Pelliccia and colleagues2 reported on a longitudinal assessment in young Olympic athletes engaged in rowing, canoeing, cycling, middle- and long-distance running, cross-country skiing, swimming, or participating in triathlons. The investigators concluded that extreme endurance training over long stretches of time (4 to 17 years) was not associated with significant changes in LV shape and function or the occurrence of cardiovascular symptoms and events. However, this unique study has been criticized for including only athletes who had undergone mandatory cardiovascular screening before enrollment, so those already having exercise-induced cardiac abnormalities would have been excluded.3 A second criticism was that no analysis of the right ventricle (RV) was performed, although extreme exercise can cause RV dysfunction and arrhythmias.3 Generally, the risk of primary cardiac arrest is increased among men with infrequent vigorous exercise, whereas, for those exercising habitually, the overall risk is decreased. There is a striking male predominance of sudden death among athletes. Article see p 13 What happens with the RV and the atria during long-term intensive sports training? Previous data indicated disproportional changes in the RV and LV …

Serial Changes in Left Ventricular Shape Following Early Mitral Valve Repair

Mitral valve (MV) repair has become the preferred treatment for mitral regurgitation associated with degenerative MV disease. Although the functional benefits of early MV repair are known, the associated alterations in left ventricular (LV) shape have not been studied. The aim of this study was to evaluate serial changes in LV performance and 3-dimensional (3D) shape after MV repair using a new analytic technique. Fifty patients (mean age 59 +/- 12 years) with severe asymptomatic mitral regurgitation and ejection fractions >55% who underwent MV repair were enrolled. Transthoracic real-time 3D echocardiography was performed the day before and 6 and 12 months after MV repair. An age-matched control group of 50 normal subjects was studied for comparison. Endocardial surfaces were extracted to compute 3D shape indexes of sphericity and conicity, which were compared in patients between different time points and versus the normal group. Postoperatively, LV volumes were decreased compared to presurgical values. Ejection fractions were slightly decreased 6 months after surgery but had restored by 12 months. These changes were associated with modifications in end-diastolic LV shape: before surgery, compared to normal controls, sphericity was augmented and conicity was decreased; at 6 months, these shape changes were reversed, with no further improvements at 12 months. In conclusion, patients with asymptomatic mitral regurgitation and preserved LV function already exhibit changes in LV shape. Early MV repair leads to near normal morphology after surgery, indicating the benefits of this procedure. Real-time 3D echocardiography and novel 3D shape analysis allow detailed serial examination of the complex relation between LV performance and shape.

Three-dimensional echocardiographic assessments of exercise-induced changes in left ventricular shape and dyssynchrony in patients with dynamic functional mitral regurgitation

Left ventricular (LV) shape and LV dyssynchrony are two cofactors associated with functional mitral regurgitation (MR) in patients with heart failure. Both can be accurately examined by real-time three-dimensional echocardiography (3DE). We examined the relationship between dynamic MR and exercise-induced changes in LV shape and synchronicity using 3DE. Fifty patients with systolic LV dysfunction underwent 2D and 3D quantitative assessment of LV function, shape, and synchronicity at rest and during symptom-limited exercise test. According to the magnitude of change in MR, patients were divided into EMR group (15 patients, 30%), if the degree of MR increased during test, and NEMR group. During exercise, the changes in LV volumes and ejection fraction were similar in both groups, whereas changes in mitral valvular deformation parameters, in LV sphericity index, and in the extent of LV dyssynchrony were more pronounced in the EMR group. At rest, only the 3D sphericity index could distinguish the two groups. By stepwise multiple regression model, dynamic changes in the systolic dyssynchrony index, sphericity index, and coaptation distance were associated with dynamic MR (r(2) = 0.45, P = 0.012). Dynamic MR during exercise is related to the 3D changes in LV shape and in LV synchronicity.

Normal asynchrony of left ventricular long and short axes: Their relationship with aortic hemodynamics

Background The relationship between left ventricular (LV) long and short axes, aortic pressure ( P), flow velocity ( U) and wave intensity is not well established. Methods Eleven dogs were anaesthetized and mechanically ventilated and LV long and minor axes shortening velocities were calculated using ultrasound crystals. P and U were measured in the ascending aorta using a high fidelity pressure catheter and ultrasonic flow transducer. Results Pre-ejection: The LV minor axis began to shorten as the long axis lengthened creating LV shape change. Early ejection: The aortic valve opened 83 ± 20 ms after the ECG Q-wave. Aortic P and U simultaneously increased; peak aortic velocity and maximum minor axis shortening velocity ( M max) occurred at 152 + 24 and 147 + 24 ms, respectively; p = 0.66, intra-class correlation ICC 0.93). M max also corresponded to the time when the reflected compression wave arrived back to the heart (ICC 0.75). Late ejection: LV long axis reached its peak shortening velocity 28 + 21 ms later than the minor axis at 175 ± 33 ms, coinciding with peak LV pressure (187 + 25 ms; p = 0.77, ICC 0.65) and onset of the forward expansion wave (177 + 28 ms, p = 0.88, ICC 0.89). Both axes then continued to slow until 210 ± 30 ms when an increased rate of decline of shortening velocity corresponded with peak aortic pressure. Conclusion Long axis peak shortening velocity lagged consistently behind the minor axis, representing a degree of normal asynchrony. The arrival of the reflected wave appears to bring about the slowing down of the minor axis.

Letter by Sengupta et al Regarding Article, “Mechanisms of Preejection and Postejection Velocity Spikes in Left Ventricular Myocardium: Interaction Between Wall Deformation and Valve Events”

To the Editor: We read with great interest the article by Remme et al.1 Although the study implies a strong association between the preejection and postejection phases and velocity spikes, we believe there are several aspects of heterogeneity in myocardial mechanics that merit further discussion. In the experiments, the creation of acute mitral regurgitation reduced the preejection spike. However, left ventricular (LV) pressure was also reduced (eg, from >80 mm Hg to about <40 mm Hg, as shown in Figure 1 of the article by Remme et al). Therefore, the marked reduction in the preejection velocity spike may reflect reduction in preejection pressure …

Real-Time 3-Dimensional Echocardiography

One of the most significant developments of the last decade in ultrasound imaging of the heart was the evolution of 3-dimensional (3D) imaging from slow and labor-intense offline reconstruction to real-time volumetric imaging. This imaging modality provides valuable clinical information that empowers echocardiographers with new levels of confidence in the diagnosis of heart disease. We have previously described the technological milestones in the development of real-time 3D echocardiographic (RT3DE) imaging and its major advantages over conventional 2-dimensional echocardiography (2DE) and reviewed the published literature that supported the use of this new methodology in clinical practice.1 Since 2006, the growing availability of RT3DE technology, its ease of use, and its multiple attractive features have sparked significant interest in the research community, resulting in a large number of publications, most of which have endorsed RT3DE imaging for clinical use by demonstrating its unique capabilities in different scenarios. In parallel, the clinical acceptance of this new tool has broadened significantly. The most recent clinically significant addition is matrix-array transesophageal echocardiography (TEE), which provides images of unprecedented quality that aid surgeons and interventional cardiologists in planning and guiding procedures and evaluating their outcomes. The purpose of the present article is to review the most recent RT3DE literature and provide readers with an update on the latest developments and the current status of this noninvasive imaging tool. Because different potential applications of RT3DE imaging have been explored to various extents, they are described here separately, and each is discussed with an emphasis on the scientifically established facts, along with the known stumbling blocks and difficulties. A firmly established advantage of 3D imaging over cross-sectional slices of the heart is the improvement in the accuracy of the evaluation of left ventricular (LV) volumes and ejection fraction (EF) by eliminating the need for geometric modeling, which …

P7: The Coapsys ® device produces a reduction in mitral regurgitation and positive left ventricular remodeling

Background: The management of patients with heart failure generally focuses on reversing the effects of deleterious left ventricular (LV) remodeling. The Coapsys device is surgically implanted and is designed to treat functional mitral regurgitation (MR) by changing the shape of the mitral annulus and LV. The purpose of this evaluation is to determine if these acute changes in LV shape produce evidence of positive chronic LV remodeling in addition to reductions in the degree of MR from annular modification.

Ventricular Remodeling in Children With Left Ventricular Dysfunction Secondary to Various Cardiomyopathies

The ventricular remodeling that occurs in adults with left ventricular (LV) dysfunction is characterized by a change in LV shape from an ellipse to more of a sphere and is associated with increased functional mitral regurgitation (MR), decreased exercise tolerance, and poor outcome. There are limited data on the occurrence and importance of LV remodeling in children with LV dysfunction. The purposes of this study were to evaluate in children with LV dysfunction (1) LV shape, (2) changes in LV shape as LV function improves, and (3) the relation between LV shape and functional MR. Children with LV dysfunction were identified and compared with controls. Patient demographics, treatment, and outcomes were noted. Echocardiograms were reviewed for LV function and shape (sphericity index). The echos of a subset of children whose LV ejection fractions (LVEFs) increased by >10% over a follow-up of >6 months were analyzed for changes in sphericity, mitral annulus size, and the degree of MR. Twenty-five children with LV dysfunction were compared with 37 age-matched controls. LV remodeling to a more spherical shape was inversely related to LVEF but was not associated with clinical outcome. In a subset of patients (n = 17) whose LVEFs improved, the reversal of remodeling (decrease in sphericity index) was associated with a decrease in MR and mitral annulus size. In conclusion, LV remodeling occurs in children with LV dysfunction. The reversal of this remodeling with a decrease in the degree of MR and the size of the mitral annulus occurs as systolic function improves.