Fifteen of 165 infants and young children who underwent surgical correction of congenital cardiac defects using profound hypothermic and circulatory arrest experienced generalized or focal seizures postoperatively. The cause of the seizures was unexplained in ten. Among these ten, the onset of seizures was 25 to 48 hours after surgery. With appropriate treatment, all had complete seizure control by the third postoperative day. During 11 to 54 months (mean, 35.6 months) of follow-up, no further seizures occurred and none had neurological abnormalities. Long-term anticonvulsant therapy was not required for any of the children. There was no correlation between the type of cardiac abnormality (cyanotic v acyanotic) or the duration of hypothermic circulatory arrest and the development of seizures. Unexplained seizures following cardiac surgery with hypothermia and circulatory arrest are not a sign of permanent brain damage and do not detract from the use of this technique for early definitive repair of congenital heart defects.
Ehyai A, Fenichel GM, Bender HW. Incidence and Prognosis of Seizures in Infants After Cardiac Surgery With Profound Hypothermia and Circulatory Arrest. JAMA. 1984;252(22):3165–3167. doi:10.1001/jama.1984.03350220071035