The hemodynamic response to physical exercise has prognostic significance in pulmonary hypertension (PH), but the right ventricular (RV) behaviors underlying this signal are not precisely defined. We prospectively analyzed patients with PH and control patients with other diseases in whom PH was invasively ruled out. All underwent three dimensional echocardiography, pressure volume (PV) catheterization, and right heart catheterization (RHC) at rest and during stepwise semi supine exercise.

Patients were considered to show a homeometric response when exercise led to increased contractile reserve with preserved end systolic to arterial elastance (Ees/Ea) coupling. Those not fulfilling this criterion were assigned to a heterometric group, which tended to show volume recruitment and dilatation under load. The slope of mean pulmonary arterial pressure to cardiac output (mPAP/CO slope) did not differentiate between groups and was lower in controls. In contrast, a larger rise in systolic pulmonary arterial pressure (sPAP) combined with a higher peak cardiac index (CI) marked the homeometric response, while smaller changes identified the heterometric pattern.

Patients with heterometric adaptation were more likely to experience clinical deterioration and had higher mortality during follow up. Overall, exercise unmasks two functional strategies of the RV in PH, with the homeometric response reflecting preserved reserve, while the combined change in sPAP and peak CI provides a practical tool for classification and prognostication.

Find the full article here: https://onlinelibrary.wiley.com/doi/10.1002/ejhf.3802