Coexistence and exercise exacerbation of intraleft ventricular contractile dyssynchrony in hypertensive patients with diastolic heart failure

Abstract

Background: Patients with heart failure (HF) and a normal left ventricular ejection fraction usually present with diastolic dysfunction (DD). Whether intraleft ventricular contractile dyssynchrony (IVCD) coexists with DD and contributes to the clinical manifestations of HF remains unclear. The study investigated the IVCD at rest and after exercise in hypertensive patients with diastolic HF (DHF).

Methods: Echocardiography was performed in 60 hypertensive patients with narrow QRS, left ventricular ejection fraction > or = 50%, and no active ischemia. Patients were grouped as having DD (mitral E/A < 1 plus E deceleration time > 200 milliseconds, or mitral annular early diastolic velocity < 8 cm/s; n = 26), DD plus HF symptoms/signs (DHF, n = 13), or as non-DD (n = 21).

Results: At rest, the IVCD index (SD of 12 left ventricular segmental electromechanical delays) was greater in the DHF and DD groups than that in the non-DD group (52.2 +/- 10.7 and 39.1 +/- 23.6 vs 23.1 +/- 19.9 milliseconds; P < .05 for both comparisons). Six-minute treadmill exercise induced exacerbation of dyssynchrony in the DHF group (67.0 +/- 12.9 vs 52.2 +/- 10.7 milliseconds; P < .001). Multivariate analysis revealed that the combination of IVCD index > or = 35 milliseconds at rest and > or = 50 milliseconds after exercise was independently associated with DHF (odds ratio = 20, 95% CI = 2-199, P = .009). Postexercise IVCD index correlated positively with plasma N-terminal pro-brain natriuretic peptide (r = 0.37, P = .004).

Conclusions: Exercise would aggravate intraventricular dyssynchrony in hypertensive patients with DHF, implicating a potential contribution of systolic dyssynchrony to clinical manifestations.