Imaging in Pulmonary Vascular Disease-Understanding Right Ventricle-pulmonary Artery Coupling

The right ventricle (RV) and pulmonary arterial (PA) tree are inextricably linked, continually transferring energy back and forth in a process known as RV-PA coupling. Healthy organisms maintain this relationship in optimal balance by modulating RV contractility, pulmonary vascular resistance, and compliance to sustain RV-PA coupling through life's many physiologic challenges. Early in states of adaptation to cardiovascular disease-for example, in diastolic heart failure-RV-PA coupling is maintained via a multitude of cellular and mechanical transformations. However, with disease progression, these compensatory mechanisms fail and become maladaptive, leading to the often-fatal state of uncoupling. Noninvasive imaging modalities, including echocardiography, magnetic resonance imaging, and computed tomography, allow us deeper insight into the state of coupling for an individual patient, providing for prognostication and potential intervention before uncoupling occurs. In this review, we discuss the physiologic foundations of RV-PA coupling, elaborate on the imaging techniques to qualify and quantify it, and correlate these fundamental principles with clinical scenarios in health and disease. (c) 2022 American Physiological Society. Compr Physiol 12:3705-3730, 2022.

Automated summary

The right ventricle and pulmonary arterial tree are closely connected in RV-PA coupling, which involves the transfer of energy. A balance of RV contractility, pulmonary vascular resistance, and compliance is necessary to maintain this relationship. Disease progression can disrupt this balance and lead to harmful consequences. Noninvasive imaging techniques provide insights into coupling status and allow for prognostication and intervention.