The Ageing of Cardiac Infarcts, and Its Influence on Cardiac Rupture

In about 9 per cent of necropsies upon cases of fatal recent cardiac infarction hemopericardium is found as a complication (Edmondson and Hoxie, 1942; Diaz-Rivera and Miller, 1948; Friedman and White, 1944). Rupture of the heart is practically confined to the first three weeks after infarc- tion although it occasionally occurs at later stages with cardiac aneurysm. Death is not usually immediate upon rupture, but follows at an interval of several hours, being probably due to circulatory failure caused by cardiac tamponade. Rupture occurs less frequently when cardiac infarction has been recognized, and the patient is at rest in hospital; more often, and in at least five of our nine cases, the catastrophe has occurred in an imperfectly treated patient arriving at hospital either moribund or dead. In this connection it is of interest that Jetter and White (1944) found that rupture of recent cardiac infarcts occurred in no fewer than 73 per cent of a small series (27) of patients in mental institutions; they had made no complaint of pain and therefore had not been treated. In the absence of clinical evidence the authors estimated the age of the infarcts by the histological criteria of Mallory -et al. (1939). Such criteria may thus assume medico-legal importance in the absence of a clear history of the onset of infarction, since microscopical examination may be the only method of estimating the age of the lesion.