Echocardiography assessment of right ventricular-pulmonary artery coupling: Validation of surrogates and clinical utilities

Right ventricular-pulmonary artery (RV-PA) coupling indicates efficiency of energy transfer from the right ventricle to the pulmonary circulation. The gold standard measurement, end-systolic elastance/arterial elastance ratio (Ees/Ea), is derived from invasive pressure-volume loop, which is technically demanding, expensive and limited in clinical practice. Recent studies have proposed various non-invasive surrogates of Ees/Ea based on echocardiography assessment, of which TAPSE/PASP ratio is an easily-obtained and validated parameter in severe pulmonary hypertension and rapidly applicated in the diagnosis and risk evaluation of various diseases and cardiac intervention. In this review, we summarized principles and validations of echocardiographic surrogates, and their clinical utilities and also limitations. The goal is to systematically review the research advances of echocardiography assessment of RV-PA coupling and help to guide clinical practice.