Finding an infant with a congenital heart lesion is always an interesting event in a children's clinic. The presence of a dissociation between the upper and lower chambers of the heart makes it doubly so, especially when this is accompanied by tachycardia and apparent arrhythmia, as any derangement in the youthful conducting system is rare in comparison with that of the adult heart with its past possibilities and tendency to scleroses and degenerations.
Up to the time this paper was written (June, 1928), twenty-one graphically proved cases of congenital heart block have been reported in the literature. These are represented in the accompanying table under their most prominent features which show some resemblance in the age of the patients, the clinical diagnosis of ventricular septal defect, the bradycardia, the usual lack of symptoms and the frequency of the change in the grade of block present.
A congenital defect in the