Right Ventricular Physiology and Pathophysiology in Acute Pulmonary Embolism

Right ventricular (RV) dysfunction is related to adverse clinical outcomes in acute pulmonary embolism (PE); however, in contrast to the left ventricle, the RV has historically received less attention. This high-volume, low-pressure pump is exquisitely sensitive to abrupt increases in pulmonary vascular resistance. In cases of acute PE, several compensatory mechanisms may become overwhelmed progressing into a vicious cycle of autoaggravation leading to obstructive shock. An understanding of RV physiology is a requisite to the management of the patient with intermediate- or high-risk PE. Physiologic considerations inform on strategies spanning from preload modification, perfusion pressure maintenance, contractility augmentation, and afterload reduction. The interactions between the respiratory system and the RV can be particularly deleterious and demand understanding when faced with the critically ill patient with acute PE. In this chapter, we review the physiology of the RV, describe the impact of acute PE on the cardiovascular system, and offer physiologic insights into the management of acute RV dysfunction.