Chronic beta adrenergic blockade in arterial hypertension: Hemodynamic influences of dihydralazine and dynamic exercise and clinical effects of combined treatment

Two series of patients with essential hypertension were studied in order to elucidate hemodynamic and clinical effects of administration of a combination of a peripheral vasodilator and a beta adrenergic blocking agent. The acute vasodilating effects of intravenously administered dihydralazine and dynamic exercise on systemic hemodynamics were studied before and during chronic beta adrenergic blockade with orally administered alprenolol in 8 inpatients. The beta adrenergic blockade did not interfere with the acute blood pressure-reducing effect of dihydralazine, thus indicating that alprenolol does not antagonize the hypotensive action of hydralazines. Further, the increase in blood pressure during exercise was significantly smaller after chronic beta adrenergic blockade; the response of cardiac output was unchanged. Eleven men and 3 women were studied clinically. Two had stage 1 disease, 7 had stage 2 disease, and the remainder stage 3 disease, according to the World Health Organization classification. The main criterion for admission to the study was unsatisfactory adjustment of blood pressure with previous medication. With an oral combination of hydralazine and alprenolol, a marked reduction in blood pressure, in many cases down to or just above normal values, could be obtained without adverse effects. It is concluded that a combination of a peripheral vasodilator like hydralazine and a beta adrenergic blocking agent may have therapeutic advantages in the sustained treatment of arterial hypertension.