[The influence of antiarrhythmic drugs on the exercise-ecg (author's transl)].

The influence of five most common antiarrhythmic drugs on exercise-electrocadiogram was investigated: prajmaliumbitartrat, quinidinbisulfate, diphenylhydantoine, propranolol, and verapamil. All exercise-tests were performed in eight healthy males. During exercise and the subsequent resting period, the changes in the following parameters were analysed: blood pressure, heart rate, P-Q-time, Q-T-time, and the formal course of the Ecg as well as individual reactions. None of the drugs produced a pathological ECG. As for the analysed parameters, diphenylhydantoine was entirely neutral, whereas propranolol caused the most significant changes. Propranolol lowered heart rate by more than 20% and blood pressure by 10%. Verapamil had a less pronounced effect on diastolic blood pressure and heart rate. Prajmaliumbitartrat and quinidine had no definite effect during exercise and resting period.