Villarraga, Hector R.

Abstract 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.

ObjectiveTo evaluate whether global peak systolic strain (PSS) and peak systolic strain rate (PSSR) derived from velocity vector imaging (VVI) allow early recognition of regional and global right ventricular (RV) dysfunction and the impact of this on left ventricular (LV) function in patients with pulmonary hypertension (PHT).BackgroundRV function is an important determinant of prognosis in patients with heart failure, pulmonary hypertension, heart transplant, and congenital heart diseases. However, evaluation of the right ventricle is often limited by its complex geometry and inadequate visualization of RV free wall. Furthermore, the impact of RV dysfunction on the LV function is not well elucidated.MethodsNinety‐nine participants, 35 control patients with normal RV systolic pressure (RVSP) (<30 mm Hg) and 64 patients with PHT (25 with mild‐to‐moderate increase in RVSP [≥36 and <60 mm Hg] and 39 with severe increase in RVSP [≥60 mm Hg]), underwent comprehensive echo‐Doppler assessment and velocity vector imaging (VVI) for strain rate analysis. RV regional peak systolic and diastolic tangential velocity, strain, and strain rate were obtained from the basal, mid and apical segments of the RV free wall and interventricular septum (IVS) from apical 4‐chamber view at end‐expiration. Similar data were obtained from eighteen LV segments from apical 4‐chamber, 2‐chamber, and long‐axis views.ResultsPeak systolic strain, strain rate, and tangential velocity at all segments in the RV free wall and IVS were decreased compared to controls in patients with PHT (P < 0.001). Significant correlation (r > 0.60; P < 0.001) was noted between RVSP and systolic and diastolic strain and strain rate at basal segment in IVS and global RV function. Peak early diastolic strain rate at all segments was also decreased in PHT patients compared with control patients (P < 0.01). Furthermore, RV systolic and diastolic strain and strain rate were lower in group 2 with mild‐to‐moderate hypertension while the conventional echo parameters were normal. Except for IVS segments, other LV segments had no statistical differences in systolic and diastolic velocity, strain, and strain rate compared to controls. However, they were lower than the published normal range.ConclusionsStrain and strain rate derived from VVI demonstrates early recognition of systolic and diastolic RV dysfunction in patients with PHT compared to controls. PHT is associated with global and regional RV systolic and diastolic dysfunction. Systolic and diastolic strain and strain rate from LV was lower compared to controls but were not statistically significant. This may indicate subclinical LV dysfunction in these patients, suggesting that conventional LV function parameters may not be sensitive to recognize subclinical LV dysfunction.

The recent introduction of novel anticancer therapies, including bevacizumab (BVZ) and sunitinib (SNT), is associated with an increased risk of cardiotoxicity. However, early identification of left ventricular (LV) systolic dysfunction may facilitate dose modification and avoid the development of advanced heart failure. Using a murine model of BVZ- and SNT-mediated cardiotoxicity, we investigated whether cardiac biomarkers and/or tissue velocity imaging (TVI) using echocardiography can detect early changes in cardiac function, before a decrease in LV ejection fraction is identified. A total of 75 wild-type C57Bl/6 male mice were treated with either 0.9% saline, BVZ, or SNT. Serial monitoring of blood pressure, high-sensitivity troponin I, and echocardiographic indexes were performed over a 14-day study period, after which the mice were euthanized for histological and biochemical analyses. Mice treated with either BVZ or SNT developed systemic hypertension as early as day 7, which increased by day 14. Cardiac biomarkers, specifically high-sensitivity troponin I, were not predictive of early LV systolic dysfunction. Although conventional LV ejection fraction values decreased at day 13 in mice treated with either BVZ or SNT, TVI confirmed early LV systolic dysfunction at day 8. Histological and biochemical analysis demonstrated loss of cellular integrity, increased oxidative stress, and increased cardiac apoptosis in mice treated with BVZ or SNT therapy at day 14. In a murine model of BVZ- or SNT-mediated cardiomyopathy, noninvasive assessment by TVI detected early LV systolic dysfunction before alterations in conventional echocardiographic indexes.

Background— Obstructive sleep apnea is highly prevalent in patients with cardiovascular disease and has detrimental effects on systolic and diastolic function of the ventricles. In this research, the changes in strain (S) and strain rate (SR) during the performance of the Mueller maneuver (MM) in an effort to better understand how negative intrathoracic pressures affect ventricular mechanics. Methods and Results— The MM was performed to maintain a target intrathoracic pressure of −40 mm Hg. Echocardiography was used to measure various parameters of cardiac structure and function. Myocardial deformation measurements were performed using tissue speckle tracking. Twenty-four healthy subjects (9 women; mean age, 30�6 years) were studied. Global left ventricular longitudinal S in systole and SR in early filling were significantly decreased during the MM (S: baseline, −17.0�1.6%; MM, −14.5�2.2%; P <0.0001, SR: baseline, 1.09�0.20 s −1 ; MM, 0.92�0.21 s −1 ; P =0.01). Global right ventricular longitudinal S was also significantly decreased during the MM (baseline, −22.0�3.1%; MM, −17.2�2.5%; P <0.0001), as was global right ventricular longitudinal systolic SR (baseline, −1.34�0.35 s −1 ; MM, −1.02�0.21 s −1 ; P =0.0006). Conclusions— Left ventricular and right ventricular longitudinal deformation are significantly reduced during the MM. These results suggest that negative intrathoracic pressure during apnea may contribute to changes in myocardial mechanics. These results could help explain the observed changes in left ventricular and right ventricular mechanics in patients with obstructive sleep apnea.