Left-sided valve dysfunction with extreme giant left atrium and anomalous coronary sinus connection after atrioventricular septal defect repair

A 51-year-old woman who had undergone surgical repair for partial atrioventricular septal defect (AVSD) at age 2 years, presented with breathlessness on exertion that had been worsening since age 32 years. The primary surgical repair for the partial AVSD included atrial septal defect patch repair using a Gore-Tex (W. L. Gore & Associates) patch, intentionally leaving the coronary sinus connected to the left atrium (LA) to prevent aortic valve node injury, cleft closure of the anterior leaflet, and commisuroplasty of the posteromedial commissure of left-sided valve.