[Modification of resting and effort hemodynamics in essential arterial hypertension using antihypertensive agents]

The haemodynamic effects of piretanide, acebutolol and nifedipine were tested and compared at rest and on exercise in an open study of patients with essential hypertension, grade II (WHO). All three drugs lowered the blood pressure significantly, both at rest and on exercise. There was no significant difference between the three drugs in their effect on resting blood pressure, but nifedipine and acebutolol were significantly more effective than piretanide in lowering it on exercise. Piretanide lowered the blood pressure by reduction in cardiac output and peripheral resistance, nifedipine entirely through a reduction of peripheral resistance, and acebutolol entirely through a reduction in cardiac output. Mean pulmonary arterial pressure, taken as a measure of left-ventricular filling pressure, was significantly reduced by piretanide and nifedipine, while it rose significantly under acebutolol. Taking into account the haemodynamics of essential hypertension (raised peripheral resistance, decreased cardiac output, frequently increased left-ventricular filling pressure), nifedipine most nearly fulfilled the role of an "ideal" antihypertensive agent.