Shape of Pulmonary Artery Doppler Flow Profile and Right Ventricular Hemodynamics in Neonates

Abstract

To characterize pulmonary artery Doppler flow profile (PAFP) patterns among infants receiving care in neonatal intensive care units (NICUs) and to examine the association of PAFP patterns with pulmonary and right ventricular (RV) hemodynamics. This is a retrospective study at two tertiary NICUs over 4 years that included neonates who demonstrated a complete tricuspid regurgitation envelope on targeted neonatal echocardiography (TNE). Separate personnel reviewed TNEs to characterize PAFP patterns, divide cohort into PAFP groups, and measure quantitative indices of RV hemodynamics (RV systolic pressure [RVSP], pulmonary artery acceleration time [PAAT] and its ratio with RV ejection time [RVET/PAAT], tricuspid annular plane systolic excursion [TAPSE] and RV output [RVO]), for intergroup comparisons. We evaluated TNEs from 186 neonates with median (IQR) gestational age of 28.5 weeks (25.9-35.9) weeks. Four distinct PAFP patterns were identified: A. near-isosceles triangle (22%), B. right-angled triangle (29%), C. notching (40%), and D. low peak velocity (<0.4 m/s; 9%). Groups A-C demonstrated a stepwise worsening in all indices of PH, while pattern D was associated with lower TAPSE and RVO. Using common definitions of pulmonary hypertension (PH), pattern A performed best to rule out PH [sensitivity range 81-90%] and pattern C for diagnosing PH [specificity range 63-78%]. Inspection of PAFP is a simple bedside echocardiography measure that provides clinically meaningful information on underlying RV hemodynamics and may aid in screening and monitoring of patients for PH in NICUs.