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.
Age-related vascular stiffening coupled with systolic ventricular stiffening may limit
cardiovascular reserve and, thus, exercise performance in aged individuals.
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.
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
(VO2) at that time (both p < 0.01). Total exercise duration prolonged by +6 +/- 2.7%
(p < 0.05) with no change in maximal VO2. Baseline cardiodepression from verapamil
reversed by peak exercise with net increases in stroke volume and cardiac output (p
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.