Evaluation of the antiarrhythmic efficacy of mexiletine in patients with chronic ventricular arrhythmias.

For the evaluation of arrhythmias and the assessment of antiarrhythmic therapy prolonged periods of recording, as provided by the Holter system, are needed. The 12 lead electrocardiogram and rhythm strips are unsuitable for these purposes. However an exercise test may provide useful additional information. In two trials mexiletine was compared with other antiarrhythmic drugs (atenolol, disopyramide, lorcainide) and placebo. In both trials mexiletine was shown to have a good antiarrhythmic efficacy on chronic ventricular premature beats. The high incidence of side-effects was probably due to the high dosage used.