Concentric hemorrhagic necrosis of the myocardium: A morphological and clinical study

Abstract

Forty-nine cases of concentric hemorrhagic necrosis of the left ventricular myocardium were reviewed in a series of 97 autopsy studies in patients subjected to cardiopulmonary bypass for various types of cardiac surgery. The gross and microscopic findings were analyzed in order to define the morphologic evolution of the lesion. The extent of involvement was graded by gross examination of serial transverse sections of the heart. Microscopically there were five major histologic changes, probably representing the sequential evolution of the lesion, i.e., contraction bands, subendocardial hemorrhages, coagulative necrosis, healing by granulation tissue, and fibrosis. The location of the lesion coincided with the vulnerable region of the microcirculation. Owing to the implementation of new surgical techniques, the cases were subdivided into two groups, one covering the period from 1963 to 1970 and the other, 1971 to 1974. Concentric hemorrhagic necrosis was less frequent in the more recent group, but when it was present it was more pronounced in the individual heart. The lesion in the earlier group was milder but demonstrated a higher incidence of platelet microthrombi in the heart. In the recent cases concentric hemorrhagic necrosis tended to be more diffuse in aortocoronary bypass than in valvular replacement surgery. We discuss one possible explanation for the development of this lesion, i.e., transient hypoxemia occurring at the time of cardiopulmonary bypass, followed by reperfusion and accelerated necrosis with hemorrhage.