Physiopathology of right heart failure

Abstract

The physiopathology of the right heart failure is tightly linked to the particular features of the right ventricle (RV). Its small dimension along with the specific geometry ensures the compliance of the RV which is able to accommodate extreme variations in venous return. Myocardial dysfunction, pressure overload, volume overload, and preload reduction are the main mechanisms of right heart failure. Due to its particular pattern of contraction, the RV better adapts to volume overload than to pressure overload. There are several aspects underlying the relative resistance of the RV to ischemia: its lower oxygen demand, dual coronary supply, and perfusion during both systole and diastole. Another key role in the pathophysiology of RV dysfunction is the ventricular interdependence. In case of acute pressure or volume overload, the RV dilates shifting the interventricular septum to the left, which along with the increased pericardial constraint determines low cardiac output. As the filling pressures rise, the auto aggravation of the low cardiac output state becomes an irreversible vicious cycle.