Subacute bacterial endocarditis superimposed on a congenital cardiac anomaly is not an uncommon occurrence. Cardiac, arterial or valvular malformations are liable to become the seat of acute inflammatory processes. The explanation offered is that the malformation or the sclerosis of tissue becomes a suitable place for the growth of organisms that may at times circulate in the blood stream. Abbott1 said that bacterial endocarditis occurred in 20 per cent of cases of patent ductus arteriosus; in 25 per cent of high patent interventricular septal defects; in 33 per cent of defects of the lower part of the interauricular septum; in 24 per cent of cases of pulmonary stenosis, and in 42 per cent of cases with fused semilunar cusps. In a total of 555 cases of congenital cardiac disease of clinical significance, endocarditis occurred in 98 cases (17.6 per cent).
Inflammation of the pulmonary artery with no involvement of