Effects of exercise on postexercise ventricular-arterial coupling and pulsatile efficiency in patients with systolic dysfunction

Abstract

Background A suboptimal ventricular-arterial (VA) interaction may have a prolonged depressing effect on the failing heart after functional reserves forced to their limits under stress conditions such as exercise. The continuation of excessive load in the postexercise period may be more important than the load during exercise, because the sum of postexercise periods generally exceeds exercise time itself. We sought that exercise-induced changes in postexercise VA coupling and pulsatile efficiency in patients with heart failure (HF). Methods Thirty consecutive HF with reduced ejection fraction (EF) and thirty age-, sex- and peak VO2-matched subjects with preserved EF were enrolled. Pre- and postexercise echocardiographic and tonometric measurements were taken to calculate left ventricular and arterial elastances, arterial compliance and wave reflections, and steady and pulsatile power. Results VA coupling significantly deteriorated in HF group (from 1.50 +/- 0.47 to 2.00 +/- 0.75 mmHg/mL, P < 0.01), but control group maintained basal favourable coupling status after exercise (from 1.04 +/- 0.29 to 1.03 +/- 0.24 mmHg/mL, P = 0.77). Pulsatile percentage of total power significantly increased with exercise in HF group, whereas it showed a significant decrease in control group. The change in pulsatile power fraction was correlated with the change in augmentation pressure (r = 0.41, ss = 3.00, P < 0.01) and inversely correlated with the change in total arterial compliance (r =.0.29, ss =.8.52, P = 0.02). Conclusion Our data indicate that exercise-induced VA decoupling and pulsatile inefficiency extend into postexercise phase in patients with systolic dysfunction. The exact duration of these derangements requires further studies.