Figure 51-4 Intraoperative pre-cardiopulmonary bypass epicardial echocardiogram in the long-axis view. Note the insertion of the papillary muscle of the tricuspid valve on the interventricular septum. Based on this view, the surgeon decided that ventricular septal defect (VSD) closure was possible in a child thought preoperatively to be only a candidate for palliation. LA, left atrium; LV, left ventricle; RV, right ventricle.