Comparison of eight echocardiographic methods for determining the prevalence of mechanical dyssynchrony and site of latest mechanical contraction in patients scheduled for cardiac resynchronization therapy.

Prevalence of echocardiographically assessed mechanical dyssynchrony and consistency in detection of the latest mechanical left ventricular (LV) contracting region when different echocardiographic methods are used in the same patient remains ill-defined. The objectives of this study were to evaluate (1) the prevalence of intraventricular mechanical dyssynchrony and (2) consistency of latest mechanical LV contraction using a multiparametric approach derived from tissue Doppler imaging (TDI), 3-dimensional (3D) echocardiography, and speckle tracking in patients scheduled for cardiac resynchronization therapy (CRT). In 63 patients with heart failure scheduled for CRT, 2D echocardiography, TDI, 3D echocardiography, and speckle tracking were prospectively collected and analyzed. Prevalence of dyssynchrony was low for some tissue-velocity derived indexes (11%, 13%, and 43%) but was >or=80% for strain derived by TDI, for systolic dyssynchrony index by 3D echocardiography, and for longitudinal and radial strains by speckle tracking. Prevalence of dyssynchrony was 69% for maximum delay between anteroseptal and posterolateral walls by radial strain. Agreement among dyssynchrony indexes was generally low (kappa -0.02). Agreement of each of these echocardiographic indexes in determining, in the same patient with heart failure, the latest LV mechanical contraction site was also low (no site agreement in 77%). In conclusion, in a typical CRT population there is considerable variability among various techniques that assess prevalence of mechanical dyssynchrony and in identification of the latest mechanical LV contracting region.