Abstract
Four cases of tetralogy of Fallot in which right bundle branch block with left anterior hemiblock occurred after surgical repair are reported. In 2 cases right bundle branch block and left anterior hemiblock were present in the first postoperative tracings. In another case complete heart block was followed by “pure” right bundle branch block, and left anterior hemiblock occurred a few days later. In another case left anterior hemiblock was only transient, but right bundle branch block remained. The electrocardiographic changes were similar to those described in right bundle branch block with left anterior hemiblock occurring spontaneously in acquired heart disease. The cases presented also support the assumption that the electrocardiographic changes commonly observed in patients with endocardial cushion defects are due to the occurrence of right bundle branch block with left anterior hemiblock.
