The hyperplastic muscle columns which encroach upon the branch mouths of the coronary arteries and their relation to coronary heart disease.

Hyperplastic muscle columns encroaching upon the branch mouths of the main coronary arteries were revealed in 1 out of every 5 infants, children, juveniles, adolescents, young adults, mature adults and elderly people. They prevailed at the branching points of the first diagonal and first septal vessels and occupied 1/3 to 2/3 of the coronary wall thickness. The presence of hyperplastic muscle bundles encroaching upon the branch mouths of the main coronary arteries was associated with the absence at the respective sites of branch pads or cushions, intimal connective tissue and atherosclerotic lesions. This peculiar microarchitecture was present in 3 times more frequently in patients who died of coronary heart disease than in subjects who died of non-cardiac causes (30% versus 10%). The existence of a relationship was suggested between the hyperplastic muscle columns encroaching upon the branch mouth of an artery and the infarction area in the myocardium supplied by the respective vessel. Likewise, a relationship seemed to exist between hyperplastic muscle columns encroaching upon the branch mouths of the vessels supplying the sinoatrial and atrioventricular nodes and the electrical instability of the heart, particularly of ventricular fibrillation leading to sudden cardiac death.