Autolytic changes in the human myocardium. Particularly with a view to detecting acute myocardial infarction by the Nitro-BT method.

Abstract

Very few studies are available on autolytic changes in the human myocardium. We therefore made a study of 30 hearts maintained in situ. Fifteen hearts were studied on an average 91/2 hours postmortem, and the other 15 hearts on an average 74 hours postmortem. Two myocardial slices from each heart were incubated for 30 minutes at 37°C in a solution consisting of substrate, Nitro-BT and buffer. Twenty-five hearts were intensely and uniformly blackish blue in appearance, due to the formation of diformazan in the myocardium, whereas five hearts presented unstained areas. These areas were evaluated as being recent myocardial infarcts. Micro-enzymatic studies of the same hearts revealed corresponding results. With increasing postmortem intervals, the diformazan appeared as coarse, uneven and disarranged granules. With regard to the commonly accepted parameters pertaining to recent myocardial infarct, histological study showed these parameters to vary so much from one heart to another and from one area to another within the individual heart that we abandoned quantitative analysis of these changes. The macro- and micro-enzymatic dehydrogenase reaction is well-suited for the detection of acute myocardial infarction in all cases up to and including the third postmortem day.