There have been a number of previous reports of partial or complete heart block associated with congenital cardiac lesions in infants. Nevertheless, this condition is not common. Holt and McIntosh1 made the brief statement that congenital complete block is usually not associated with serious cardiac abnormalities. Griffith and Mitchell2 said only that it may occur, especially in association with defects of the interventricular septum but also with other congenital malformations.
Congenital heart block is rare for two reasons. First, interventricular septal defects are usually anterior to the membranous septum, while the bundle of His runs posterior to it. Second, it has long been known, from the researches of Monckeberg,3 that the development of the interventricular septum takes place after the development of the bundle of His, and it is unlikely that malformations of the septum will interfere with the development of the bundle after the latter has
HOEKENGA MT. COMPLETE HEART BLOCK IN AN INFANT ASSOCIATED WITH MULTIPLE CONGENITAL CARDIAC MALFORMATIONS. Am J Dis Child. 1945;69(4):231-233. doi:10.1001/archpedi.1945.02020160031005