O1024: Notching of the Pulmonary Valve Doppler Signal Is Highly Associated with Pulmonary Hypertension

Background: Notching of the pulmonary valve (NPV) Doppler signal represents a reflected systolic pressure wave from the pulmonary vasculature often seen in those with pulmonary hypertension (PH). We hypothesize that NPV is associated with worse pulmonary vascular resistance (PVR) and pulmonary artery compliance (PAC).

Methods: This was a retrospective study of patients ≤ 21 years with a cardiac catheterization to assess suspected PH and an echocardiogram obtained ≤ 30 days prior. Those without a pulmonary valve were excluded. Echo measurements were made blinded to disease severity and catheterization data. Measurements included pulmonary ejection and acceleration time, peak velocity, velocity time integral, and tricuspid regurgitant velocity (TRV). NPV was defined as an indentation in the initial two-thirds of the systolic Doppler signal (Figure). PH was defined as PVR ≥ 3.0 Wu m2. PAC was calculated as the pulmonary stroke volume divided by pulmonary pulse pressure (mL/mmHg). Subgroups were compared using Wilcoxon rank sum or odds ratio where appropriate. Receiver operator characteristic curves were utilized to evaluate a continuous variable’s discriminatory ability for a diagnosis of PH.

Results: In total, 87 patients were included. There were 27 patients (31%) with NPV and 60 (69%) without (Table). There were no significant differences in demographics, history of congenital heart disease, pulmonary stroke volume, or ratio of pulmonary-to-systemic output.
NPV patients had higher PVR (p < 0.001) and TRV (p = 0.01), and lower PAC (p = 0.004). Presence of NPV had 94% specificity, and 96% positive predictive value for a diagnosis of PH. Sensitivity, however, was poor at 38%. TRV was as specific as NPV at high values (93% at 3.9 m/sec), though was accurately obtained or clinically applicable in only 51 total patients (59%). The NPV subgroup had decreased ejection time, acceleration time, peak velocity, and velocity time integral, all of which were poor discriminators for PH (area under curve = 0.34-0.47, p > 0.05). Seven of the 27 NPV patients had a hemodynamically significant VSD, for whom a TRV was not clinically meaningful.

Conclusion: NPV is an easily obtainable echocardiographic metric associated with worse PVR and PAC. When present, there is a very high likelihood of a catheterization-confirmed diagnosis of PH. NPV appears worthy of further investigation in patients with suspected PH.