Supravalvar Mitral Ring with Complete Atrioventricular Septal Defect: A Case Report and Three-Dimensional Echocardiography Evaluation

Supravalvar mitral ring (SVMR) is a rare cause of congenital mitral stenosis. It can occur in isolation but often coexists with other cardiac anomalies, such as a ventricular septal defect or left-sided obstructive lesions. Conversely, a complete atrioventricular septal defect (AVSD) is a much more common anomaly. An AVSD may be associated with other major cardiac defects, such as tetralogy of Fallot, transposition of the great arteries, or double-outlet right ventricle. The authors describe what they believe is the first case of SVMR and complete AVSD occurring together; the SVMR was diagnosed by two-dimensional echocardiography, and its morphology could be more accurately delineate using three-dimensional echocardiography.