Right ventricle and venous system: bridging physiology and clinical practice. A narrative review

The cardiovascular system primarily delivers oxygen and nutrients to tissues. Oxygen delivery depends on cardiac output and arterial oxygen content. While left ventricular function is often emphasized, broader cardiovascular changes, including peripheral vascular function and right ventricular performance, are crucial, especially during shock or cardiopulmonary interactions with mechanical ventilation or fluid challenges. Indeed, the primary role of the left ventricle is to maintain a high central arterial pressure with a minimal filling pressure and to do so efficiently with every beat. Cardiac output is driven by tissue metabolic demand, as feeding arterioles adjust their vasomotor tone to autoregulate blood flow. These adjustments are reflected in proportional changes in venous return to the right ventricle. Right ventricular dysfunction reduces cardiac output primarily by causing systemic venous hypertension, a condition the cardiovascular system is poorly adapted to. Understanding these principles is vital for managing the optimization phase of shock resuscitation. In this narrative review, we aim to provide a comprehensive discussion of the physiological determinants of hemodynamics of circulatory function in shock. This structured yet flexible approach offers an integrative perspective on right ventricular and venous function, highlighting their complexity in hemodynamic regulation.