Supramitral valve obstruction from hypertrophied native atrial tissue as a complication of orthotopic heart transplantation.

An acquired form of cor triatriatum, resulting in significant supramitral valve obstruction, complicating a pediatric orthotopic heart transplantation was diagnosed by transesophageal echocardiography. Surgical resection of the hypertrophied atrial septum and atrial wall corrected the anatomic obstruction and improved the hemodynamics.