What is the incidence and clinical significance of combined left anterior hemiblock and right bundle-branch block after surgical closure of VSD and correction of tetralogy of Fallot?
Combined left anterior hemiblock and right bundle-branch block occurs in 6-11% of patients after VSD or tetralogy of Fallot repair but appears to have a benign long-term clinical course.
Combined left anterior hemiblock and right bundle-branch block after surgical closure of ventricu- lar septal defects and correction of tetralogy of Fallot is evaluated in 240 patients. It was found that 7 of IO9 patients or 6-4 per cent with ventricular septal defect and I4 of I3I patients or IO-7 per cent with tetralogy of Fallot developed this combination of conduction disturbances as a consequence of intracardiac operations. All patients are alive and completely asymptomatic i to 1O years after operation. No serious side effects have occurred except for transient heart block in
Downing et al. (Wed,) studied this question.