Varicella myocarditis presenting with unusual ventricular arrhythmias.

A 10-year-old boy with varicella developed syncopal episodes caused by runs of self-terminating ventricular tachycardia and ventricular fibrillation. These arrhythmias were thought to be caused by varicella myocarditis and were resistant to most common antiarrhythmic agents. Continuous electrocardiographic recording and analysis proved extremely useful in the management of this case. Mexiletine, a new antiarrhythmic drug, was finally effective in controlling recurrent attacks of ventricular tachycardia.