Comparison of Echocardiographic Dyssynchrony Assessment by Tissue Velocity and Strain Imaging in Subjects With or Without Systolic Dysfunction and With or Without Left Bundle-Branch Block

Abstract

A substantial proportion of normal subjects have tissue velocity-derived dyssynchrony indexes higher than the cutoff value proposed for predicting beneficial effect of cardiac resynchronization therapy. Strain-derived timing index appears to be more specific for dyssynchrony in patients with systolic dysfunction and left bundle-branch block. Identifying an optimal tissue velocity- or strain-derived dyssynchrony index requires a large prospective clinical trial.