[The influence of mexiletin on ventricular arrhythmias during ergometric exercise (author's transl)]

Wireless telemetric ECG observations and suitably-graded ergometric loads to reach an age-dependent maximum heart rate of about 130/min. are suited for the critical examination of released ventricular arrhythmias requiring therapeutic aid. In the recovery period after ergometric exercise the incidence of ventricular arrhythmias is twice as great as at rest or during normal physical activity. Even in the recovery period distinct ST depressions were observed. The hypothesis that myocardial ischaemia predisposes to ventricular arrhythmias as a result of electrophysiological instability is apparently supported by these findings. Mexitil--a potent class I antiarrhythmic drug--significantly reduced the incidence of ventricular arrhythmias at rest, normal physical activity and after ergometric loading during initial intravenous therapy followed by continuous oral administration over a three-week period at a daily dosage of 600 to 800 mg. No significant haemodynamic effects were observed, especially with respect to the pump function of the heart during oral or intravenous therapeutic administration.