Unraveling the RV Ejection Doppler Envelope: Insight Into Pulmonary Artery Hemodynamics and Disease Severity

Abstract

ObjectivesThe purpose of this study was to characterize the profiles of right ventricular outflow tract (RVOT) Doppler flow velocity envelopes in patients with pulmonary arterial hypertension (PAH) and to establish whether changes in the RVOT flow profile related to patient outcome. BackgroundThe RVOT systolic flow profile is frequently abnormal, with findings of a mid-systolic flow deceleration and notching, previously proposed as an indicator of elevated pulmonary vascular resistance (PVR). MethodsWe reviewed RVOT systolic flow profiles recorded by pulsed-wave Doppler from 159 consecutive patients with PAH and measured deceleration time (DT) of mid-systolic deceleration slope (mid-systolic DT) and the peak velocity of pre- and post-notching flow. Concurrent right-heart catheterization was available in all (41 of 41) incident patients and in 39 of 118 established patients. Outcomes, defined as time to all-cause mortality or need for lung transplantation, were assessed during 3 years of follow-up. ResultsNotched envelopes were identified in 150 of 159 patients. The presence of a notched pattern and a decrease in the mid-systolic DT were associated with higher PA pressures; higher PVR; and, at a threshold of a mid-systolic DT of <120 ms, worse outcome. Those patients with a shorter DT were further subdivided based on the post-notch systolic flow velocity. In these patients, a decline in the post-notch flow velocity to <62% of the pre-notch flow velocity defined a cohort with a marked reduction in systolic function and the worst outcome. ConclusionsIn PAH, the notched profile of RVOT Doppler flow velocity envelope appears to integrate indicators of pulmonary vascular load and RV function and serves as a marker for adverse outcomes.