RESUMEN
The present study evaluated the prevalence of mechanical inter- and intraventricular dyssynchrony in patients with heart failure and preserved left ventricular (LV) ejection fraction (LVEF). We studied 138 patients with heart failure (age 67+/-11 years; 76% men); 60 patients had preserved LVEF (>40%). Using conventional Doppler echocardiography, an interventricular mechanical delay>or=40 ms was defined as interventricular dyssynchrony. Using pulse-wave tissue Doppler imaging, the time from the beginning of the QRS complex to onset of systolic motion was measured in 4 basal LV segments. A dispersion of >or=60 ms was defined as intraventricular dyssynchrony. The prevalence of inter- and intraventricular dyssynchrony was lower in patients with preserved LVEF than in those with reduced LVEF (17% vs 41%, p<0.01 for interventricular dyssynchrony, 18% vs 36%, p<0.01 for intraventricular dyssynchrony). However, patients with preserved LVEF and a QRS width>or=120 ms had higher values for the parameters for inter- and intraventricular dyssynchrony than patients with a QRS width<120 ms (interventricular mechanical delay 33+/-20 vs 20+/-16 ms, p<0.05; tissue Doppler imaging dispersion 42+/-26 vs 33+/-22 ms, p<0.05). In patients with a QRS width>or=120 ms, the prevalence of inter- and intraventricular dyssynchrony was comparable for patients with preserved and reduced LVEF (42% vs 55%, p=NS for interventricular dyssynchrony and 45% vs 46%, p=NS for intraventricular dyssynchrony). In conclusion, the prevalence of inter- and intraventricular dyssynchrony was low (17% and 18%, respectively) in patients with heart failure and preserved LVEF. However, in the presence of a QRS width of >or=120 ms, this prevalence increased to almost 50%, comparable to that for patients with heart failure and reduced LVEF and a QRS width of >or=120 ms.