[Effects of antihypertensive drugs with different mechanism of action on cardiac hemodynamics in patients with artificial pacemaker].

Cardiohemodynamic effects of obsidan, nifedipin, captopril and prasosine were compared when the drugs were given in a 4-week course regarding circulation type and stimulation regime to 74 patients with artificial pacemaker suffering from mild or moderate essential hypertension. A peculiar action of obsidan, nifedipin and prasosine in cardiac pacing found at echocardiography is explained by the absence of frequency-dependent (chronotropic) cardiohemodynamic effects. Obsidan lowered blood pressure most effectively in hyperkinetic circulation. Nifedipine, captopril and prasosine were more potent in eu- and hypokinetic circulation. Reduction of arterial pressure by the above peripheral vasodilators in patients with hyperkinetic circulation results from a fall of total peripheral vascular resistance initially elevated by 16.5%, on the average. In isolated ventricular stimulation (regime VVI) vs atrial one (AAI regime) hypotensive action of the above drugs was more potent, but side effects were more frequent.