Effect of intravenous calcium antagonists on left ventricular diastolic function in hypertension: assessed by pulsed-Doppler echocardiogram

OBJECTIVE: To investigate the acute effects of the calcium antagonists nicardipine and diltiazem on blood pressure and left ventricular diastolic filling in hypertensive patients. DESIGN: Transmitral flow velocities were measured by pulsed-Doppler echocardiography before and during infusion of nicardipine (1, 2 and 3 micrograms/kg per min) and diltiazem (5, 10 and 15 micrograms/kg per min) in seven patients with essential hypertension. Arterial pressure was measured directly, and other haemodynamic indices were obtained using a right-sided heart catheter. RESULTS: The calcium antagonists significantly decreased blood pressure and total peripheral resistance. Changes in mean blood pressure correlated with those in total peripheral resistance. Heart rate was significantly increased by nicardipine but decreased by diltiazem. Nicardipine and diltiazem both increased significantly the peak early filling velocity and the peak velocities of early: late filling ratio. The changes in the ratio correlated inversely with those in total peripheral resistance. CONCLUSION: Intravenous infusion of nicardipine or diltiazem causes a fall in blood pressure by decreasing total peripheral resistance, with beneficial effects on left ventricular diastolic filling that are independent of changes in heart rate in patients with hypertension.