[Effects of diltiazem on hemodynamics, plasma catecholamine and renin activity during exercise in hypertension].

The effects of diltiazem on hemodynamics, plasma catecholamine and plasma renin activity were studied during treadmill exercise test in 9 cases with moderate essential hypertension. Diltiazem of 120 mg/day was orally administered for 4 weeks. At maximum exercise, significant decrease in systolic blood pressure (-32 mmHg), heart rate (-16/min), pressure-rate product (-7,883 mmHg/min), plasma norepinephrine (-195 ng/L) and plasma epinephrine (-11 ng/L) were observed; while, diastolic blood pressure, ST depression and plasma renin activity showed no significant change. Also, a significant correlation between systolic blood pressure and plasma norepinephrine (r = 0.57, p < 0.001), especially after diltiazem therapy (r = 0.68, p < 0.001), was observed. These findings indicated that diltiazem can reduce the secretion of catecholamine from the sympathetic nerves during exercise in patients with essential hypertension.