The structure and function of the helical heart and its buttress wrapping. VII. Critical importance of septum for right ventricular function.

The macroscopic structure of the right ventricle includes a transverse basal loop for the free wall, and oblique septal components, originating from the descending and ascending segments of the apical loop. Data is presented that determines why right ventricular function is related principally to intraventricular septal function, and why right ventricular failure is magnified by septal stunning caused by poor myocardial protection. The background of this architectural/functional change can explain normal right ventricular function, the relationship of right ventricular performance to pulmonary vascular resistance, experimental studies that characterize right ventricular performance after architectural free wall ablation, right ventricular disconnection, right coronary occlusion, and free wall replacement. These basic science studies are related to perioperative right ventricular performance, involving methods of myocardial protection, protamine reaction, right coronary occlusion and reperfusion, right ventricular dyskinesia, chronic aortic and mitral valve replacement (MVR) replacement, congenital heart disease, right and left ventricular assist devices (LVADs), and transplantation. The predominant focus is related to the septum and how it can be evaluated perioperatively. Septal evaluation by echocardiogram should become an essential feature during intraoperative management.