We describe an infant with complex congenital heart disease, including double orifice of the mitral valve associated with complex subaortic stenosis. Transthoracic and intraoperative transesophageal echocardiography were used to define three distinct anatomic abnormalities, all potentially contributing to the subaortic obstruction. Stepwise surgical repair with transesophageal echocardiographic monitoring of hemodynamic function ensured optimal initial surgical results. Overwhelming postoperative complications ensued, however, and the patient died. Postmortem findings are also presented.
