Comparison of Multidirectional Myocardial Deformation Result From Pressure and Volume Overload in Compensatory Stage

Abstract

Aortic stenosis (AS) and aortic regurgitation (AR) were two types of aortic valve defects which had different hemodynamic characteristics. Ultimately, chronic pressure and volume overloads result in different geometrical and functional patterns. The expectation of our study was to compare the impacts of two different types of loading conditions on myocardial deformation in asymptomatic patients with normal ejection fraction in compensatory stage using three-dimensional speckle tracking echocardiography (3D-STE). Among severe aortic valve disease, 36 patients with AR, and 32 patients with AS were enrolled. All subjects underwent conventional two-dimensional echocardiography and 3D-STE. Clinical and echocardiography characteristics were compared between the groups. Compared with control group, left ventricular twist was increased, along with decreased longitudinal, radial, and circumferential strain in the AS group. And AR patients were characterized by a spherical expansion of ventricle, and reduced myocardial longitudinal and radial strain, along with a preserved rotational motion. In univariate linear regression analysis, age, diastolic blood pressure, e’, sphericity index, end-diastolic volume index, stoke volume index, ejection fraction, and left ventricular mass index were independently associated with global longitudinal strain (GLS) in the AR group and relative wall thickness, stroke volume index (SVI), LV mass index, and peak velocity were independently associated with GLS in the AS group. In addition, multiple stepwise regression analysis showed that sphericity index, SVI, and left ventricular ejection fraction (LVEF) were independently associated with GLS in the AR group. And LVEF, peak velocity, and left atrial dimension were independently associated with GLS in the AS group. The affected myocardial layers of AS patients were worse than AR patients, but increased twist was the compensatory mechanism to maintain the effective stroke volume. Multidirectional myocardial damages alert clinicians to be aware that these patients need closer attention.