Acquired Left Atrial-to-Right Ventricular Shunt with Mitral Valve Incompetence: A Rare Sequela after Repair of Atrioventricular Septal Defect

Acquired left ventricular-to-right atrial communication is encountered periodically. This condition is chiefly attributable to surgical mishaps, trauma, endocarditis, or endomyocardial biopsy. In a few instances, a Gerbode-like defect develops after the repair of an atrioventricular septal defect. Our search of the worldwide medical literature revealed just 1 report of a “mirror” occurrence of a Gerbode-like defect: a shunt between the left atrium and the right ventricle. Herein, we present the case of a 22-year-old woman who had severe mitral valve incompetence accompanying an acquired shunt between the left atrium and the right ventricle—a late sequela of the earlier repair of an atrioventricular septal defect. After surgical correction of the shunt and the associated mitral incompetence, the patient experienced a good outcome. Echocardiographic and intraoperative findings are presented, along with a plausible explanation for the mechanism and presentation of the condition in our patient. To our knowledge, this is only the 2nd report of an acquired shunt between the left atrium and the right ventricle, and the 1st such case to be accompanied by severe mitral valve incompetence.