In patients with pulmonary hypertension (PH) and normal left ventricular function, differences in right ventricular (RV) morphology have been shown to be strongly predictive of increased afterload and thus the hemodynamic nature of PH. A retrospective review of clinical data from patients with PH published in Echocardiography sought to assess whether a particular RV morphology might help provide insight into the hemodynamic profiles of individuals with PH.

The investigators reviewed clinical, 2-dimensional (2D) echocardiographic, and hemodynamic data from 100 patients with PH. The participants were divided into 3 groups: PH from pulmonary vascular disease (PH_PVD; n=34), with pulmonary vascular resistance (PVR) >3 mm Hg/L/min (Wood unit [WU]) and pulmonary artery wedge pressure (PAWP) ≤15 mm Hg; pulmonary venous hypertension (PVH; n=33), with PVR <3 WU and PAWP >15 mm Hg; and PH of mixed physiology (PH_MIXED; n=33), with PVR >3 WU and PAWP >15 mm Hg. A number of 2D parameters of right heart morphology and function were analyzed, including the degree of tapering of the RV diameter from base to apex in the apical 4-chamber view (P <.05).

Baseline characteristics of the participants were similar in the 3 groups. The average age was 62±14.4 years, 69% of the participants were women, and 57% were white. The hemodynamics and 2D echocardiographic data in the PH_PVD vs PVH vs PH_MIXED arms were as follows: PVR: 13±6 WU vs 2±1 WU vs 7±2 WU, respectively; mean pulmonary artery pressure: 53±14 mm Hg vs 34±8 mm Hg vs 49±8 mm Hg, respectively; and cardiac index: 2.0±0.5 L/m² vs 2.8±0.7 L/m² vs 2.2±0.7 L/m², respectively.

In addition, RV base/apex ratio during systole (sRV_b/a) was 1.3±0.2 vs 2.6±0.5 vs 1.5±0.3, respectively. Therefore, sRV_b/a was 2-fold higher in the pressure-matched PVH cohort vs the pressure-matched PH_PVD cohort (2.8±1.9 vs 1.4±0.3, respectively; P =.007).

Based on their findings, the researchers concluded that sRV_b/a ratio is a simple 2D index of RV shape that is a strong predictor of PVR >3 WU and provides powerful insight into the presence or absence of PVD among a diverse population of patients with PH.

Reference

Raza F, Dillane C, Mirza A, et al. Differences in right ventricular morphology, not function, indicate the nature of increased afterload in pulmonary hypertensive subjects with normal left ventricular function [published online September 24, 2017]. Echocardiography. doi: 10.1111/echo.13699