Diaphragmatic contraction band necrosis in a perinatal and infantile autopsy population

A morphologic study of the anterolateral costal diaphragm in 125 newborns and infants who died suddenly showed that contraction band necrosis is a common finding. In cases that showed the most extensive lesions, acute asphyxia was the usual mode of death; within eight diagnostic categories birth asphyxia (11 of 26 cases) and sudden infant death syndrome (19 of 30 cases) had the highest frequency of lesions. It was more frequent than myocardial contraction band necrosis and myocardial coagulation necrosis among the cases studied. The morphologic age and, if present, the stage of healing in each case suggested that the diaphragmatic lesion commenced at or shortly before death or at the time of the cardiac arrest that led to death. Thus, the lesion appeared to represent a very early event after a lethal injury, but it had no specificity for the nature of the injury. Because skeletal muscle of the respiratory diaphragm structurally and functionally resembles myocardium, the pathogenesis of contraction band necrosis may be similar in the two muscle types.