Sudden death among postoperative patients with tetralogy of Fallot: a follow-up study of 243 patients for an average of twelve years.

Abstract
Two hundred and forty-three patients were evaluated following total correction of tetralogy of Fallot with special emphasis on postoperative conduction disturbances and on the occurrence of sudden death. The average follow-up period was 12 years with a range of 6 1/2 to 16 1/2 years. Sudden death occurred in seven patients. Four deaths were among those with right bundle branch block pattern (RBBB) and three of the four had premature ventricular contractions (PVC) for more than one month postoperatively. PVCs were documented in ten of the 158 patients with RBBB; sudden death occurred in three (30%). Three of the ten (30%) patients with trifascicular block pattern (TB) died suddenly, while no deaths occurred in 24 patients with bifascicular block pattern (BB). Progression of RBBB to BB and TB occurred in 18 patients from one month to seven years postoperatively (58% of BB and 40% of TB). The risk of sudden death in patients with RBBB and PVCs following tetralogy repair is high and warrants consideration of suppressive therapy. TB also carries a high risk. The finding that RBBB may progress to BB or TB mandates long-term careful follow-up of all tetralogy patients with postoperative conduction disturbances.