ALPHA‐RAY ACTIVITY IN CORONARY ARTERY DISEASE

A bstract : The ash concentrations and the alpha‐ray activities of the coronary and of the common carotid arteries were examined in 16 subjects who died of ischaemic heart disease (average age, 64.8 years), and in 17 subjects who died of other causes (average age, 62 years). The ash concentrations in the coronary arteries of the subjects with fatal ischaemic heart disease were twice as high as in those of the controls. They were very low in the common carotid arteries of both groups. Ulcerative and calcified atheromatous lesions in the common carotid arteries were rare at all ages. Postmortem radiography of these vessels revealed distinctly more calcium deposits in the coronary arteries of the subjects with fatal ischaemic heart disease than in those of the controls. No calcium deposits were visible in the common carotid arteries of both groups. The wet‐tissue alpha‐ray activities in the coronary arteries of the subjects with fatal ischaemic heart disease were four times higher than in the coronary arteries of the controls, five times higher than in their own common carotid arteries, and ten times higher than in the common carotid arteries of the controls. The mean value of the alpha‐ray activities in the coronary arteries of subjects with fatal ischaemic heart disease equals that found for human bones. It is higher than in any other soft tissue in the human body. X‐irradiation of the larger arteries can produce severe atheromatous lesions in animals and in human beings within a relatively short time. The concept is advanced that the small amounts of alpha‐radiation in the arterial wall, which increase with age, may cause subtle injuries to the arterial structures, thus contributing to the development of atherosclerosis.