Ischemic papillary muscle necrosis in stressed newborn infants.

The recent association of transient tricuspid insufficiency in newborn infants with ischemic papillary muscle necrosis prompted a detailed retrospective clinical and histologic analysis of autopsied infants who died within seven days of birth between 1973 and 1977. Infants with congenital heart disease, erythroblastosis fetalis, and known congenital viral infections were excluded. Thirty-one of 82 infants had at least one site of ischemic myocardial necrosis: 11 had lesions only in the right ventricle, 13 had lesions only in the left ventricle, and seven had bilateral lesions. The apical region of an anterior papillary muscle was the most common site. IMN occurred more commonly in older, larger infants. Asphyxia at birth, a murmur of atrioventricular valve insufficiency, and signs of congestive heart failure correlated well with the presence of IMN, but few other perinatal events predicted its occurrence. This report suggests that IMN is a common event in stressed infants who die early in life and probably is related to episodic hypoperfusion of the myocardium.