Quantitative, Noninvasive Assessment of Patent Ductus Arteriosus Shunt Flow by Measuring Proximal Isovelocity Surface Area on Color Doppler Mapping in Very Low-Birth-Weight Infants

Abstract

Background Our goal was to evaluate the hemodynamic status of very low-birth-weight infants (VLBWIs) with patent ductus arteriosus (PDA) by measuring the vena contracta width (VCW) and effective shunt orifice area (ESOA) using the proximal isovelocity surface area (PISA) on color Doppler imaging. Method and Results In this study, 34 VLBWIs with PDA (median weight: 949 g) were studied. We measured VCW and ESOA using the PISA on echocardiography. PDA-VCW was measured at the narrowest PDA flow region. ESOA determined using PISA (PDA-ESOA) was defined as the hemispheric area of laminar flow with aliased velocities on color Doppler flow imaging: PDA-ESOA = 2π (PDA radius) 2 × aligning velocity/PDA velocity. Of the 34 VLBWIs, 26 received indomethacin (IND) for symptomatic PDA. Comparing echocardiographic parameters between infants who did versus did not receive IND, significant differences were seen in the left atrial-to-aortic root ratio (LA/AO), PDA-VCW, and PDA-ESOA. Receiver operating characteristic curve analysis to differentiate between IND usage status produced statistically significant results for PDA-VCW (area under the curve [AUC] = 0.880), PDA-ESOA (AUC = 0.813), and LA/AO (AUC = 0.769). Conclusion PDA-VCW and PDA-ESOA may allow noninvasive assessment of PDA severity, and are useful when determining the timing of clinical decision making for IND administration.