Significance of cardiac murmurs in term neonates admitted to a neonatal intensive care unit of a tertiary level hospital in India

Introduction: There is a paucity in the literature of prospective studies on neonatal heart murmurs and their correlation with the diagnostic yield on 2D echocardiography.

Objectives: To assess the prevalence of cardiac murmurs in neonates and their significance using 2D Echocardiography/Colour Doppler.

Method: A prospective descriptive analytical study was carried out on 100 term neonates admitted to the neonatal intensive care unit (NICU) of a tertiary level hospital from April - November 2017 with audible systolic (grade 2/6 or above), diastolic (2/4 or above) or continuous murmurs. These patients were evaluated with a detailed 2D Echocardiogram /Colour Doppler on portable Sonosite / Epiq using an 8-12 Hz probe. Patient with isolated small patent foramen ovale (<5mm) and those admitted to the NICU with diagnosed cardiac disease were excluded from study. A 100 term neonates without murmur were used as controls. The results obtained were statistically analysed using SPSS software. p < 0.05 was taken as significant Institutional Ethics Committee approval was obtained prior to study.

Results: Of the 100 neonates with murmur, 65 (65%) had significant structural defects and 35 (35%) had no structural heart defects. The mean hospital stay was 13.03 days. Seventy five (75%) neonates had good outcome and 25 (25%) had poor outcome in the form of prolonged NICU stay and mortality. Of the 100 neonates without murmur, 97 (97%) had good outcome and 3 (3%) had poor outcome due to non-cardiac issues.

Conclusions: The prevalence of murmurs among neonates was 6.2 per 1,000 live births in inborn  deliveries (excluding previously diagnosed cases). Complex structural abnormalities were found in 28% of neonates with murmurs. The rest had isolated lesions or single structural lesions such as VSD (19%), PDA (18%) or ASD (2%).