Abstract: | Acquired nonsurgical complete atrioventricular block is uncommon in children. We report an 11-year-old asymptomatic girl with endocardial cushion defect who gradually developed progressive conduction abnormality and complete atrioventricular block prior to open heart surgery. To our knowledge, a gradual progressive, nonsurgical, acquired atrioventricular block in endocardial cushion defect has not been described before. This report discusses the possible pathogenesis of acquired nonsurgical complete atrioventricular block in endocardial cushion defect and reviews the literature. |