Congenital heart block with fatal Adams-Stokes attacks in childhood

Congenital heart block may be associated with Adams-Stokes attacks in children with slow heart rates and QRS complexes of prolonged duration. The attacks are almost always associated with upper respiratory infections. The mechanism in two of three cases was ventricular tachycardia, or ventricular tachycardia followed by ventricular arrest. At autopsy, moderate endocardial fibrosis was found in two cases. A small atrial septal defect was present in one. These and other reported fatal cases of congenital heart block in infancy and childhood suggest that the clinical course is not as benign as previously suggested.