Shape of the right ventricular Doppler envelope predicts hemodynamics and right heart function in pulmonary hypertension.

Abstract

Systolic deceleration or "notching" of the right ventricular outflow tract Doppler flow velocity envelope (FVE(RVOT)) relates to pathologic wave reflection in the setting of elevated pulmonary artery impedance. We investigated whether simple visual assessment of FVE(RVOT) morphology aids in hemodynamic differentiation and detection of pulmonary vascular disease among a referral pulmonary hypertension (PH) cohort. We reviewed hemodynamics, echocardiography, and clinical data for 88 patients referred for PH and 32 subjects with systolic heart failure and PH. The FVE(RVOT) was categorized as normal (no notch [NN]); late systolic notch (LSN); or midsystolic notch (MSN). The pulmonary vascular resistance (PVR) was highest in the MSN group (9.2 ± 3.5 Wood's units [WU]; P < 0.001) versus the LSN (5.7 ± 3.1 WU) and NN (3.3 ± 2.4 WU) groups. The ratio of stroke volume to pulse pressure (compliance) also differed by FVE(RVOT) morphology (MSN = 1.2 ± 0.5; LSN = 1.7 ± 0.8; NN = 2.6 ± 1.7; P = 0.001 and 0.04, respectively, vs. NN). MSN was 96% specific and 71% sensitive for a PVR >5 WU (positive predictive value, 98%). The MSN group had severe right ventricular dysfunction (tricuspid annular plane systolic excursion 1.6 ± 0.5 cm) relative to the LSN and NN groups (tricuspid annular plane systolic excursion 1.9 ± 0.6 vs. 2.2 ± 0.6 cm; both P < 0.05). In the PH cohort, any FVE(RVOT) notching (MSN or LSN) was highly associated with PVR >3 WU (odds ratio, 22.3; 95% confidence interval, 5.2-96.4), whereas the NN pattern predicted a PVR less than or equal to 3WU and pulmonary artery wedge pressure greater than 15 mm Hg (odds ratio, 30.2; 95% confidence interval, 6.3-144.9). Visual inspection of the shape of the FVE(RVOT) provides insight into the hemodynamic basis of PH in a referral PH cohort. MSN is associated with the most severe pulmonary vascular disease and right heart dysfunction.