Coronary arterial lesions and myocardial necrosis in stillbirths and infants.

In a detailed study of the coronary arterial tree and myocardium in 256 stillbirths and infants, abnormalities of the coronary arterial tree were noticed in 79 infants, and necrotic lesions of the myocardium in 111 infants. Of the 79 infants with arterial lesions, 70 had associated myocardial necrosis or scarring, or both; the group with coronary arterial lesions, therefore, accounted for the majority of cases with myocardial damage. The myocardial lesions varied from small zones of subendocardial damage, to larger 'geographical' zones of necrosis scattered haphazardly through the myocardium, and a small group where massive necrotic lesions of the papillary muscles were present. While the coronary arterial lesions were associated with all three patterns, they were particularly found in association with the 'geographical' and papillary muscle changes. The coronary arterial lesions varied from zones of acute focal, medial necrosis to severe proliferative intimal lesions and medial defects, with a distinct progression of changes from the acute to the more established lesions. The coronary arterial lesions were seen most commonly in association with conditions that could produce severe hypoxia, and it is argued that they result from hypoxia. It is suggested further that the myocardial damage, so commonly associated with the coronary arterial lesions, could compromise the ability of the hypoxic infant to respond to such an insult. The coronary arterial lesions seen in this group of young infants could offer one explanation for the later development of a variety of other pathological conditions seen in adolescents and young adults.