Frequency of inter- and intraventricular dyssynchrony in patients with heart failure according to QRS width

Abstract

A substantial proportion of patients with prolonged QRS (32.1%) did not exhibit inter- or intraventricular dyssynchrony, which may represent a limitation in identifying the ideal QRS interval for the selection of patients for CRT.

Radial dyssynchrony assessed by cardiovascular magnetic resonance in relation to left ventricular function, myocardial scarring and QRS duration in patients with heart failure

“…Similar findings have emerged from another tissue Doppler study using a six basal and six middle LV segment model. [18] In the present study, however, 99% of patients with heart failure, in NYHA class III or IV, an LVEF<35% and a QRS>120 ms had dyssynchrony. With respect to patients with heart failure and a QRS<120 ms, tissue Doppler imaging studies have shown that dyssynchrony is present in 36% to 65% of patients, [5,6,19] depending on the particular method employed.…”

Role of echocardiographic dyssynchrony parameters in predicting response to cardiac resynchronization therapy

“…3 One of the various reasons is that electrical dyssynchrony, as documented by QRS prolongation on a 12-lead ECG, is not synonymous with mechanical dyssynchrony; in fact, left ventricular mechanical dyssynchrony can occur in patients with normal QRS duration and vice versa. 4 In the search for better selection criteria for CRT, it has been shown that an echocardiographic assessment of left ventricular dyssynchrony is predictive for response to CRT, 5 despite large trials such as Prospect and RethinQ have failed to identify a single and accurate parameter predictor of response to therapy. 6,7 For several years, tissue Doppler imaging (TDI) was the standard and predominant echocardiographic technique for quantification of mechanical dyssynchrony.…”

TDI Is a Better Choice than M-Mode and 2D Echocardiography

“…A study of Fahmy Elnoamany et al [2] showed that patients with acute MI may have LV systolic asynchrony even in the absence of QRS widening or bundle branch block. In contrast, according to another report by Emkanjoo et al [3] , about 32.1% of patients with prolonged QRS do not exhibit interor intraventricular asynchrony. So we think it is not a very rigorous approach to assume that post-MI patients with IVCD have myocardial asynchrony and those without IVCD represent the normal contrast.…”