[Transient atrioventricular conduction disorder: a potential cause of sudden death in myocarditis due to varicella. A case report].

The case of a patient with varicella skin lesions presenting with heart failure at 4 years of age is described. A transitory atrioventricular conduction disturbance due to myocardial impairment was documented during hospital stay. Despite the clinical improvement with conventional therapy, the patient died from respiratory failure due to a lung infection but with an almost normal electrocardiogram. Necropsy showed myocardial lesions compatible with acute myocarditis. A possible viral specific affinity for the conduction system of the heart is suggested and judged to be a potential cause of death in this disease. Since the actual incidence of varicella myocarditis associated to an atrioventricular conduction disturbance is unknown it seems prudent that every patient with varicella infection should have a cardiac examination during the acute phase of the disease. As the diagnosis of subclinical myocarditis depends essentially on an electrocardiogram, we believe this method should be employed routinely during the acute phase in order to assess myocardial involvement in this disease, which may be a cause of sudden death.