Mechanism of action of beta-blocking drugs in angina pectoris: a review.

The effect of beta-blockers in improving exercise tolerance in angina pectoris can be accounted for by the reduction in heart rate and arterial pressure than they produce. The failure of a few patients to respond despite reduction in heart rate and the failure of those who do respond to obtain the full expected benefit suggests that beta-blockade has some action that offsets in while or in part the advantage gained from reduction in heart rate and pressure. This action might include an increase in left ventricular size with consequent increase in work, or an increase in left ventricular diastolic pressure with resultant impairment of blood flow to the inner layers of the myocardium.