Significance of early transient complete heart block as a predictor of sudden death late after operative correction of tetralogy of fallot

We evaluated the long-term outcome and incidence of sudden death in the 288 patients discharged after corrective operation for tetralogy of Fallot at the University of Minnesota between 1954 and 1974. The perioperative characteristics of these patients were evaluated with respect to their long-term outcome. A health status survey was sent to each survivor and their functional status was evaluated with respect to the perioperative variables. Current follow-up was available in 279 of 288 of the postoperative survivors (97%); the mean duration of follow-up was 28 years. The 40-year survival rate was 76% and 154 of 163 of survey responders (95%) were in New York Heart Association class I or II. Twenty-six of the 288 died suddenly (9%). Those with transient complete heart block that persisted beyond the third postoperative day had a lower long-term survival rate (p <0.001) and a higher incidence of late sudden death (p <0.001). Patients aged >12 years at operation had a lower long-term survival rate (p <0.001) and less favorable long-term functional status. The use of a transannular patch was associated with increased late morbidity but not mortality. Thus, the very long-term outcome after operative correction of tetralogy of Fallot is excellent. Late sudden death remains a concern for operative survivors, occurring in 9% of these patients. Late sudden death is strongly associated with transient complete heart block that persisted beyond the third postoperative day.