Effects of nifedipine versus hydralazine on sympathetic activity and cardiac function in patients with hypertension persisting on diuretic plus beta-blocker therapy

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Abstract
In patients with hypertension persisting on combined diuretic and beta-blocker therapy, the effects of an additional 9-week therapy with a calcium antagonist (nifedipine) versus a classical arterial vasodilator (hydralazine) were compared for changes in blood pressure (BP), plasma catecholamines (n=15), and left ventricular (LV) systolic and diastolic function (n=6). Both drugs lowered BP, but nifedipine was significantly more effective in lowering systolic BP. Hydralazine increased both supine and standing plasma norepinephrine, nifedipine increased them only in the standing position and to a lesser extent. Patients on beta1-selective (n=5) versus nonselective (n=10) blockade showed similar responses. Left ventricular systolic function was not affected by hydralazine, whereas nifedipine increased the rate of ejection. In contrast, LV diastolic function was not affected by nifedipine, whereas hydralazine improved the peak filling rate. We conclude that arterial vasodilation by a calcium antagonist causes less sympathetic activation than caused by a classical arterial vasodilator. However, during short-term therapy in patients already on a diuretic and a beta blocker, nifedipine appears not to improve decreased LV diastolic function.