Tie a yellow ribbon around a papillary muscle.

An 8-year-old boy with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals status post complete repair including a fenestrated ventricular septal defect patch presented to the catheterization laboratory for fenestration closure. During the procedure, the catheterization wire was found to have an unusual intracardiac loop and was unable to be straightened within the heart. Three-dimensional transesophageal echocardiography revealed the wire was looped around a right ventricular papillary muscle. The wire was readjusted, and the fenestration was successfully closed. Three-dimensional imaging was essential in unambiguously defining the catheter course and assisting in fenestration closure.