Does short-term verapamil administration alter systemic and brachial artery hemodynamics in normal humans?
Short-term verapamil administration in normal humans produces systemic and brachial artery vasodilatation with a reflex increase in stroke volume, contrasting with the hemodynamic effects of atenolol.
To clarify the hemodynamic effects of verapamil, we investigated in normal volunteers the effects of 4-day treatment with verapamil (240 mg/day) on left ventricular function and on systemic and brachial artery haemodynamics, in comparison with the effects of placebo and atenolol (100 mg/day). Left ventricular structure and function was evaluated by echocardiography, systemic hemodynamics were assessed by pulsed Doppler velocimetry of the ascending aorta, and brachial artery hemodynamics were assessed pulsed Doppler velocimetry of the brachial artery. Verapamil decreased systemic and brachial artery vascular resistance (p less than 0.05), increased cardiac output (CO, p less than 0.01) and brachial flow (p = 0.054), and did not affect blood pressure (BP) and heart rate (HR). In contrast, atenolol decreased BP, HR, and CO (p less than 0.001) but did not significantly affect brachial flow and systemic and brachial artery vascular resistance. We conclude that short-term administration of verapamil in normal humans produces systemic and brachial artery vasodilatation, with a reflex increase of stroke volume but not of HR.
Vanhees et al. (1989) studied this question.