EFFECTS OF HIGH-DOSES OF ORAL VERAPAMIL ON SYSTOLIC AND DIASTOLIC CARDIAC-FUNCTION IN NON-CARDIOLOGIC PATIENTS, WITH REVIEW OF THE LITERATURE

We studied the effects of high doses of oral verapamil (480 mg daily) in a group of 28 patients undergoing intravenous drug therapy for terminal digestive tumor. One additional patient was prematurely withdrawn from the study due to the occurrence of second degree atrioventricular block, which regressed after the interruption of verapamil. Gated radionuclide angiocardiography was performed before and after treatment (mean duration 2 days). Verapamil induced a significant reduction of blood pressure and heart rate (132 +/- 19 mm Hg vs 124 +/- 18 mm Hg, p = 0.005 for systolic blood pressure, 80 +/- 13 mm Hg vs 76 +/- 9 mm Hg, p = 0.04 for diastolic blood pressure and 81 +/- 17 bpm vs 77 +/- 13 bpm, p = 0.02 for heart rate). Left ventricular ejection fraction and peak filling rate were not impaired (65 +/- 7% vs 64 +/- 7%, p = NS and 2.52 +/- 0.65 EDV/s vs 2.42 +/- 0.51 EDV/s, p = NS), while peak ejection rate decreased slightly (2.96 +/- 0.72 EDV/s vs 2.72 +/- 0.50 EDV/s, p = 0.01). Conversely, there was significant alteration of right ventricular systolic indexes (50 +/- 7% vs 46 +/- 7%, p = 0.01 for the ejection fraction and 2.06 +/- 0.53 EDV/s vs 1.88 +/- 0.44 EDV/s, p = 0.008 for the peak ejection rate), without change in the peak filling rate (1.54 +/- 0.46 EDV/s vs 1.46 +/- 0.46 EDV/s, p = NS). We conclude that it is possible to prescribe high doses of oral verapamil (480 mg daily) in patients without serious left ventricular function impairment, subject to electrocardiographic supervision when initiating treatment to detect the possible occurrence of atrioventricular conduction abnormalities.