[Perinatal asphyxia and heart problems]

To evaluate the severity of cardiac complications of neonatal asphyxia in relation to the length and degree of hypoxia.

Ninety babies with an Apgar score < or = 6 were examined in the intensive care unit at our institution during seven years. Arterial blood for measuring pH, glucose, LDH and MB fraction of CK, together with serial electrocardiogram (ECG), echocardiogram and chest X rays was obtained. The fatal cases were studied with macro and microscopic examination.

From a total of 90 cases, 73 were premature: 30 (41%) appropriate for gestation age (AGA) and 43 (59%) small for gestation age (SGA). Twenty one (23%) cases had arterial pH < 7.2. The most common clinical conditions were: pneumonia 28 (31%), anemia 24 (26%) and jaundice 12 (13%). The main cardiological findings were: systolic murmur in 46 (50%), signs of heart hypertrophy in 18 (20%) and heart failure in 8 (9%). On ECG the main findings were ST and T abnormalities. The echocardiogram showed a patent ductus arteriosus (PDA) in 20 (22%), tricuspid regurgitation in 6 (7%), pulmonary hypertension in 6 (7%), dyskinesia and ventricular dilatation in 4 (5%). Necropsy was performed in 23 cases and macro and microscopy obtained in 14; the most frequent findings were: myocite necrosis in 8 (54%), congestion, vacuolization and loss of striae in 4 (29%).

In the majority of cases, patients had a benign course, even those presenting with severe acidemia. Many abnormal EKGs and echocardiograms became normal after a few weeks. Among those who had a fatal outcome, the severity of histological lesions was observed in babies who had suffered asphyxia for more prolonged periods.