Haemodynamic effects of beta-adrenergic blockade.

Abstract

Five healthy subjects and 8 patients with coronary heart disease, verified by coronary angiography, were studied at rest and during exercise which induced angina pectoris, before and after beta-adrenergic blockade. The relief of pain during work after blockade in all patients could be explained by a significant 20% decrease in left ventricular work. This decrease was related to the fall in heart rate, as stroke volume and systemic arterial pressure were unchanged. The abnormally high filling pressures for the ventricles during work decreased slightly after blockade. Left ventricular work was reduced by 25 per cent in healthy subjects but the diastolic filling pressures increased during submaximal exercise after blockade. The acid-base balance and the respiratory quotient were unchanged indicating no metabolic disturbances during work of short duration.