Isolated right ventricular hypoplasia: intraoperative balloon occlusion test.

A 42-year-old woman with isolated right ventricular hypoplasia underwent operation. To determine the optimal procedure, we temporarily occluded the atrial septal defect with a balloon catheter that was introduced through the right atrial appendage. The hemodynamics were stable throughout the occlusion test. Simple closure of the atrial septal defect was safely accomplished. Intraoperative occlusion test with the balloon catheter was a good alternative to preoperative occlusion test.