Late outcome after repair of mitral valve rupture during balloon atrial septostomy in a neonate.

Balloon atrial septostomy is ordinarily a safe palliative procedure for cyanotic congenital heart disease; however, if echocardiographic guidance is unavailable and fluoroscopy is used, distortions in the cardiac anatomy can invalidate the usual landmarks. Herein, we report iatrogenic mitral papillary muscle rupture during balloon atrial septostomy in a 4-day-old male neonate with total anomalous connection of the pulmonary veins. The anomalous connection and severe mitral regurgitation were emergently corrected, and the patient grew and developed normally. At age 24 years, he had only mild residual mitral regurgitation and was in New York Heart Association functional class I.In addition to describing the surgical treatment and positive late outcome of a rare complication, we highlight the importance of accurately evaluating balloon catheter location during atrial septostomy, especially in patients with a small left atrium.