Differences in right ventricular morphology, not function, indicate the nature of increased afterload in pulmonary hypertensive subjects with normal left ventricular function.

BACKGROUND: The aim of study was to assess whether a specific morphology of the right ventricle (RV) by 2D echo predicts the hemodynamic nature of pulmonary hypertension (PH).
METHODS: We reviewed clinical, 2D echo, and hemodynamic data of 100 patients with PH: divided into three groups: PH from pulmonary vascular disease (PHPVD ; 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 PHMIXED (n = 33) with PVR > 3 WU and PAWP > 15 mm Hg. We analyzed several two-dimensional parameters of right heart morphology and function, including the degree of tapering of the RV diameter from base (just above tricuspid annulus) to apex (level of moderator band) in the apical four-chamber view. P = <.05.
RESULTS: Baseline characteristics were similar in all three groups: age 62 ± 14.4 years, 69% females, 57% Caucasians. Hemodynamics and 2D echo data of PHPVD vs PVH vs PHMIXED were as follows: PVR 13 ± 6 vs 2 ± 1 vs 7 ± 2 WU, mean pulmonary artery pressure 53 ± 14 vs 34 ± 8 vs 49 ± 8 mm Hg and cardiac index 2.0 ± 0.5 vs 2.8 ± 0.7 vs 2.2 ± 0.7 L/m2 , RV base/apex ratio during systole (sRVb/a ) 1.3 ± 0.2 vs 2.6 ± 0.5 vs 1.5 ± 0.3. Thus, sRVb/a was twofold higher in the PVH vs PHPVD cohort. On ROC analysis, the AUC for sRVb/a for predicting PVR > 3 WU was 0.873, with optimal cutoff of 1.5.
CONCLUSION: Systolic RV base/apex ratio is a simple 2D index of RV shape that powerfully predicts a PVR > 3 WU and provides powerful discriminating ability between PVH and PHPVD .