The Physiology of Ventricular Assist Devices

Temporary right and left ventricular assist devices (RVAD and LVAD respectively) are increasingly deployed in the management of cardiogenic shock. Contemporary VADs are continuous-flow devices and understanding the altered circulatory physiology is relevant for clinical management. Continuous-flow RVADs and LVADs produce parallel circulations from the heart to the pulmonary artery and the aorta respectively, and this VAD circulation interacts with the native right and left heart systems. This review will describe the functional anatomy and physiology of contemporary continuous-flow temporary VADs, the interaction between the heart and assist devices, and the interpretation of the cardiovascular physiology.