Heart size in newborn infants with birth asphyxia

Area of Science:

• Neonatalogy
• Pediatric Cardiology
• Radiology

Background:

• Cardiomegaly is a suspected common finding in infants with birth asphyxia.
• Previous studies have not accurately determined the incidence of cardiomegaly in this population.

Purpose of the Study:

• To assess the actual incidence of cardiomegaly in neonates experiencing birth asphyxia.
• To differentiate between relative heart enlargement and absolute cardiomegaly in asphyxiated infants.

Main Methods:

• A cohort of 67 neonates with birth asphyxia (Apgar score < 6 at 1 and 5 minutes) was studied.
• Heart size was evaluated using the cardiothoracic ratio (CTR) on initial postnatal radiographs.
• CTR values were compared to established norms for healthy infants.

Main Results:

• The average CTR in asphyxiated infants was 52.8%, which was significantly higher than previously reported values for non-asphyxiated infants.
• Persistent cardiomegaly (CTR > 2 SD above normal) was observed in 19% (13 out of 67) of the infants.
• In most cases (10 out of 13) with significant cardiomegaly, other contributing medical conditions were identified.

Conclusions:

• While relative heart enlargement is frequent in neonates with birth asphyxia, absolute cardiomegaly is relatively rare.
• The presence of significant cardiomegaly in asphyxiated infants warrants investigation into other potential underlying causes.
• Focusing on secondary causes is crucial for accurate diagnosis and management of cardiomegaly in this vulnerable group.