Rationale: 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.
Objectives: 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.
Methods: 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).
Measurements and main results: 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).
Conclusions: 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.