Temporary decompression of the right ventricle to assess the right ventricle-dependent coronary circulation in pulmonary atresia with intact ventricular septum.

We repaired a case of pulmonary atresia with intact ventricular septum in which the blood supply to the left anterior descending coronary artery depended on the right ventricle. At the time of a bidirectional Glenn operation, total cardiopulmonary bypass with venous drainage from the right atrium was performed in order to evaluate the safety of right ventricular decompression required for a planned Fontan operation. We confirmed the dependence of the coronary perfusion on the right ventricle by demonstrating transient depression of the ST segment in the epicardial electrocardiogram during temporary decompression of the right ventricle. To prevent ischemic myocardial damage, we then performed an extracardiac Fontan operation with a temporary venous shunt and without cardiopulmonary bypass.