Intimal thickening and atherosclerotic involvement of the left main coronary artery.

A post mortem study carried out on 886 apparently healthy children, adolescents, young and mature adults of an unselected population sample of Bucharest who died of accidental causes, revealed that the left main coronary artery acted as an atherosclerosis-resistant segment of the coronary arterial bed. The importance of this natural resistance was demonstrated by means of a comparative investigation involving the degree of intimal thickness, the intima thickness versus media thickness ratio, the per cent of subjects with atherosclerotic plaques and the obstructive character of these plaques. These parameters were examined in 6 selected topographic sites: (a) at 5 mm distal to the origin of the left main coronary artery, compared with those detected at 10 mm and 20 mm distal to the point of origin of the anterior descending artery; (b) at 5 mm from the aortic origin of the right coronary artery, compared with those recorded at 20 mm and 30 mm from the same point of origin.