Complete atrioventricular block following myocarditis in children

Complete atrioventricular block (CAVB) can be either congenital or acquired in children. Acquired CAVB is occasionally seen in myocarditis patients. To determine the etiology, natural history, and outcome of children with acquired nonsurgical CAVB, we retrospectively reviewed nine children who had suffered CAVB caused by suspected infectious myocarditis. All of them had CAVB with a wide QRS escape ventricular rhythm on admission. Three of them had ventricular tachycardia in addition to CAVB. Seven of them had a preceding upper respiratory tract infection. All of them had congestive heart failure. Five of them had Stokes-Adams seizures. Three etiologies were identified in four of the children. All patients received inotropic agents and emergency temporary pacing. In all except one case, the cardiac rhythm returned to sinus rhythm within 10 days. During a follow-up period of 9 to 96 months, all were asymptomatic and drug-free. Electrocardiograms showed that four patients were completely normal, there was complete RBBB in four and left anterior fascicular block in one patient. We conclude that although CAVB associated with myocarditis can be life-threatening, the long-term prognosis is good if patients are diagnosed early and proper management is employed.