Echocardiographic Parameters of Patent Ductus Arteriosus in Preterm Infants

Objective: To analyze cardiovascular parameters by echocardiography in preterm infants with patent ductus arteriosus (PDA). Setting: Tertiary-care pediatric university hospital. Design: Cross-sectional, hospital-based study. Participants: 58 preterm infants, gestational age less than 33 weeks. Measurements: A complete 2-dimension, M-mode, color doppler echocardiography was performed in each preterm infant at approximately 48 hours of life. Results: Each preterm was categorized into hemodynamically significant PDA (hsPDA) (n=17, 29.3%), non-hemodynamically significant PDA (non-hsPDA) (n=12, 20.7%), and no PDA (non-PDA) (n=29, 50%). Gestational age (29.4 +/- 1.2 wk) and birth weight (1237 +/- 358 g) of infants in hsPDA were significantly lower than those in non-PDA group (30.8 +/- 1.3 wk, 1543 +/- 361 g, P = 0.001), as compared to those in the non-hsPDA group (29.5 +/- 2.3 wk, 1296 +/- 462 g). Cardiovascular parameters including left atrium/aorta ratio, left atrium volume index, left ventricular dimensions and volumes, stroke volume, and cardiac output in hs-PDA were significantly greater than those in non-hsPDA and non-PDA. LV systolic and diastolic functions were not significantly different in each group. LV global function in hsPDA (0.34 +/- 0.13) was significantly lower than that in non-PDA (0.45 +/- 0.13, P = 0.01). Conclusions: In preterm infants with hsPDA, there was a volume load of the left heart causing increased stroke volume and cardiac output. The hsPDA could be detected by echocardiography even in the first 48 hours. The left atrial volume index may be a better indicator of the volume load of the heart.