Evidence at autopsy of spasm in the distal right coronary artery in persons with coronary heart disease dying suddenly.

The aim of this study was to examine whether there are morphological signs in spasm in the coronary arteries at autopsy in persons with coronary artery disease dying suddenly. From a forensic autopsy service, 48 cases of sudden and unexpected deaths were selected: 24 cases with a preliminary diagnosis of coronary heart disease and 24 cases involving persons dying of noncoronary causes. A complete autopsy according to a preset protocol was followed with particular emphasis on the heart examination. The myocardium and the coronary arteries were sampled and examined without knowledge to which group the case belonged. The degree of folding of the internal elastic lamina of the proximal and distal parts of the coronary arteries was measured by picture analysis of elastin-stained cross sections of the arteries. The degree of folding was significantly greater in the distal section of the right coronary artery in cases of the coronary group compared to the folding in the same section in cases of the noncoronary group. In the proximal part of the right coronary artery and in the left coronary artery with its two branches, there were no differences in the folding of the internal elastic membrane between the groups. Our findings indicate that a spasmic contracture of an artery may be diagnosed postmortem. The spasm of the distal part of the right coronary artery may have caused focal ischemia in the central parts of the cardiac conducting system, precipitating a lethal arrhythmia.