Echocardiographic evaluation of left atrial volume and comparative analysis to left atrial to aortic root ratio in premature neonates and infants with patent ductus arteriosus

Purpose Left atrium to aortic root ratio (LA/Ao) is an echocardiographic marker of hemodynamically significant patent ductus arteriosus (PDA). Since 2‐dimensional measurement of the ratio is geometrically limited, left atrial volume (LAV) which has 3‐dimensional characteristics was investigated. The aim of this study was to determine a correlation between LA/Ao ratio and LAV as well as holodiastolic flow reversal in preterm neonates with and without a PDA. Methods A retrospective evaluation of neonates with and without PDA was performed. Targeted neonatal echocardiography evaluation of LA/Ao and LAV was measured from parasternal long‐axis view and the apical 4 and 2‐chamber views, respectively. Univariate and linear regression analysis were performed. Results 200 patients were included of whom 158 (79.0%) had a PDA shunt. The median gestational age at the time of echo was 27.4 weeks (IQR: 25.7–29.4 weeks). The median LA/Ao ratio was 1.51 (IQR: 1.26–1.83) and median LAV indexed to weight was .91 mL/kg (IQR: .65–1.18 mL/kg). There was a significant correlation between LA/Ao and LAV indexed to weight in the PDA group (r2 = .080, p = .0003). LA/Ao ratio and LAV indexed to weight differed significantly between those with diastolic flow reversal versus no‐flow reversal (LA/Ao, p = .003; LAV, p = .001). Conclusions This study demonstrated a significant correlation between LA/Ao and LAV in preterm infants with PDA, with greater magnitude of discordance for LAV. The power of LAV versus LA/Ao in monitoring hemodynamically significant PDA requires prospective evaluation. Left atrial volume (LAV) and left atrium (LA) to aortic root (Ao) ratio are both increased significantly in patients with patent ductus arteriosus (PDA). The statistical significance of LAV is greater and may potentially be an additional predictor of hemodynamic significance in premature infants with a diagnosis of PDA.