Atrioventricular block in childhood caused by mesothelioma.

The case of a girl who was first seen at 3.5 years of age with longstanding asymptomatic heart block is reported. Electrophysiological study disclosed a block proximal to the His bundle. She grew up normally until the age of 11.5 years, when a syncopal attack occurred. Before a pacemaker could be inserted, she suffered a second fatal attack. Necropsy revealed a tumor of the atrioventricular node diagnosed as mesothelioma. Our findings are compared to the 38 cases already described in the literature.