Improvement in left ventricular diastolic function in patients with stable angina after chronic treatment with verapamil and nicardipine

A placebo-controlled double-blind randomized crossover study was carried out to assess the effects of chronic therapy with two calcium antagonists on left ventricular diastolic function in patients with stable angina. Ventricular function was assessed using equilibrium radionuclide angiography and the data was analysed using an automated algorithm. The mean +/- SD ejection fraction on placebo was 59 +/- 10% and this remained unchanged on both verapamil (59 +/- 9%; P = NS) and nicardipine (58 +/- 7%; P = NS). Verapamil increased the peak filling rate index (P less than 0.001) and first one-third filling fraction (P less than 0.005). Nicardipine increased the peak filling rate index (P less than 0.005), but did not alter the other diastolic indices. Early filling rate index was not altered by either drug. Comparison of the effects of nicardipine and verapamil revealed no significant differences in ejection fraction, peak filling rate index or early filling rate index. However, verapamil showed a greater improvement in time to peak filling rate and first one-third filling fraction (P less than 0.01, P less than 0.01, respectively) compared with nicardipine. Heart rate (P less than 0.002) and systolic blood pressure (P less than 0.01) were also lower on verapamil than on nicardipine. These data suggest that left ventricular 'relaxation' abnormalities may be detected in patients with chronic angina pectoris before systolic dysfunction becomes apparent and that these abnormalities may be partially corrected by calcium antagonists.