Exercise testing for evaluating right ventricular (RV) function in pulmonary hypertension - A review

The purpose of this narrative review is to synthesize and discuss the various exercise testing modalities used to assess right ventricular (RV) function in pulmonary hypertension (PH), given that accurate and prompt assessment of RV function is crucial for both diagnosing the disease and predicting patient prognosis. A comprehensive literature search was conducted using electronic databases, including PubMed and Google Scholar. Keywords used included "pulmonary hypertension," "right ventricular function," "exercise testing," "cardiopulmonary exercise testing," "CPET," "RV dysfunction," "hemodynamic assessment," "right heart failure," and "exercise limitation". The review identified that RV dysfunction in PH results from complex pathophysiological mechanisms, including hemodynamic stress that leads to maladaptive remodeling, characterized by eccentric hypertrophy and compromised systolic and diastolic function. Exercise testing reveals multiple parameters reflecting RV dysfunction, including reduced VO 2 max, altered O 2 pulse, and decreased RV stroke volume during exercise. Ventilatory abnormalities such as elevated VE/VCO2 slope and reduced petCO 2 serve as important markers of impaired RV output and gas exchange. The concept of RV-arterial coupling (Ees/Ea ratio) provides valuable insights into the efficiency of RV-pulmonary artery collaboration. Exercise-induced changes in pulmonary artery systolic pressure (PASP) demonstrated prognostic significance, with lower survival rates associated with reduced PASP increases following physical activity. Exercise testing provides a comprehensive evaluation of RV function in PH patients, offering both diagnostic and prognostic value. The integration of hemodynamic, functional, and ventilatory parameters during exercise stress testing enables clinicians to better assess RV reserve capacity and guide therapeutic decision-making in pulmonary hypertension management.