Left ventricular dyssynchrony in patients with heart failure and preserved ejection fraction

Mechanical dyssynchrony has been postulated to play a pathophysiologic role in heart failure with preserved ejection fraction (HFpEF). We quantified left ventricular (LV) systolic dyssynchrony in 130 HFpEF patients with NYHA class II-IV symptoms, ejection fraction (EF) ≥45%, and NT-proBNP levels >400 pg/mL enrolled in the PARAMOUNT trial, and compared them to 40 healthy controls of similar age and gender. Dyssynchrony was assessed by 2D speckle tracking as standard deviation (SD) of time to peak longitudinal systolic strain in 12 ventricular segments and related to measures of systolic and diastolic function. Heart failure with preserved ejection fraction patients (62% women, mean age of 71 ± 9 years, body mass index of 30.2 ± 5.9 kg/m(2), systolic blood pressure 139 ± 15 mmHg) demonstrated significantly greater dyssynchrony than controls (SD of time to peak longitudinal strain; 90.6 ± 50.9 vs. 56.4 ± 33.5 ms, P < 0.001), even in the subset of patients (n = 63) with LVEF ≥55% and narrow QRS (≤100 ms). Among HFpEF patients, dyssynchrony was related to wider QRS interval, higher LV mass, and lower early diastolic tissue Doppler myocardial velocity (E'). Greater dyssynchrony remained significantly associated with worse diastolic function even after restricting the analysis to patients with EF≥55% and adjusting for age, gender, systolic blood pressure, LV mass index, and LVEF. Heart failure with preserved EF is associated with greater mechanical dyssynchrony compared with healthy controls of similar age and gender. Within an HFpEF population, the severity of dyssynchrony is related to the width of QRS complex, LV hypertrophy, and diastolic dysfunction.