Massive Cardiomegaly in a Neonate

T his 83 pound infant was the product of an uneventful pregnancy and delivery. Apgar scores were 1 and 6. Physical examination revealed a cyanotic newborn with a heart rate of 120 per minute, respiratory rate of 50 per minute, and systolic blood pressure of 90 mm Hg in all extremities. There was a grade 2/6 pansystolic murmur at the lower left sternal border, a prominent mid-diastolic murmur, and a third heart sound. The liver was enlarged 3 cm below the right costal margin and was non-pulsatile. Umbilical arterial blood gases revealed : pH of 7.36; P02 55 mm Hg; Pco2 36 mm Hg. The electrocardiogram showed first degree heart block, right atrial enlargement, right axis deviation, and right bundle