Physiology of the Failing Right Heart

The first description on the importance of right ventricular (RV) function comes from the English physician Sir William Harvey in 1616 in his seminal treatise, De Motu Cordis. He recognized that “the right ventricle may be said to be made for the sake of transmitting blood through the lungs, not for nourishing them” [1]. For almost four centuries, emphasis in physiology and cardiology was placed on left ventricular (LV) physiology, overshadowing the study of the RV, which could still be characterized as “the neglected ventricle” [2]. The intriguing hypothesis that systemic circulation could be adequately maintained without RV contractile function, as in total cavopulmonary connection, underestimated the role of the right heart [3]. During the last two decades, clinicians, mainly cardiologists and cardiac surgeons, as well as researchers, recognized the importance of right-sided function in left-sided heart failure, RV myocardial infarction, congenital heart disease (CHD), and pulmonary arterial hypertension (PAH). Advances in invasive and noninvasive imaging have dramatically improved our understanding on the anatomy and physiology of the right heart and the pulmonary circulation in both acquired and CHD. In this chapter, we describe, from a clinical perspective, the applied physiology of the normal RV, the adaptive and maladaptive pathophysiology that leads to the development of right heart failure under various conditions, and molecular aspects of RV remodeling and failure.