Verapamil acutely reduces ventricular-vascular stiffening and improves aerobic exercise performance in elderly individuals

OBJECTIVES We tested the hypothesis that acute intravenous verapamil acutely enhances aerobic exercise performance in healthy older individuals in association with a combined reduction of ventricular systolic and arterial vascular stiffnesses. BACKGROUND Age-related vascular stiffening coupled with systolic ventricular stiffening may limit cardiovascular reserve and, thus, exercise performance in aged individuals. METHODS Nineteen healthy volunteers with mean age 70 +/- 10 years underwent maximal-effort upright ergometry tests on two separate days after receiving either 0.15 mg/kg i.v. verapamil or 0.5 N saline in a double-blind, randomized, crossover study. RESULTS Baseline vascular stiffness, indexed by arterial pulse-wave velocity (Doppler) and augmentation index (carotid tonometry) declined with verapamil (-5.9 +/- 2.1% and -31.7 +/- 12.8%, respectively, both p < 0.05), Preload-adjusted maximal ventricular power, a surrogate for ventricular end-systolic stiffness, also declined by -9.5 +/- 3.6%. Peripheral resistance and peak filling rate were unchanged, With verapamil, exercise duration prior to the anaerobic threshold (AT) increased by nearly 50% (260 +/- 129 to 387 +/- 176 s) with a corresponding 13.4 +/- 4.7% rise in oxygen consumption ((V) over dot O-2) at that time (both P < 0.01). Total exercise duration prolonged by +6 +/- 2.7% (p < 0.05) with no change in maximal (V) over dot O-2. Baseline cardiodepression from verapamil reversed by peak exercise with net increases in stroke volume and cardiac output (p < 0.05), CONCLUSIONS Acute intravenous verapamil reduces ventriculovascular stiffening and improves aerobic exercise performance in healthy aged individuals. This highlights a role for heart-arterial coupling in modulating exertional capacity in the elderly, suggesting a potentially therapeutic target for aged individuals with exertional limitations. (C) 1999 by the American College of Cardiology.