Four cases of right-sided bundle-branch block and one case of atrioventricular block in three generations of a family.

Four cases of complete right bundle-branch block and one case of atrioventricular heart block, all occurring within three generations of the same family, are described. The 4 patients with bundle-branch block had no symptoms, whereas the patient with atrioventricular heart block suffered Adams-Stokes attacks from the age of 13 and died at 47 years of age. A 33-year-old man with bundle-branch block had a normal electrocardiogram at the age of 7, suggesting that inherited bundle-branch block does not necessarily manifest itself during the first years of life.