[Effect of beta receptor blockaders on exercise induced extrasystoles].

The effect of a beta-receptor-blocking drug (200 mg Acebutolol pr os) on exercise-stimulated extrabeats (ES) by an ergometrical test was studied in 56 subjects. A reduction of the frequency of premature beats to minimally 50% was considered to be a positive result, which was found in 32 subjects. The best result could be observed in old people, in supraventricular and in the case of a fairly low number of ES. On the other hand the effect was smaller in young people, in ventricular and in frequent extra beats. In three cases polytopic extrasystoles and sinus arrhytmia appeared, which were not observed before. The results give some therapeutical hints. Further they stress the necessity to test the effect of an antiarrhythmical treatment in the individual case.