DISEASES OF SMALL CORONARY ARTERIES

Normal coronary arteriographic findings are interpreted by most clinicians as evidence that coronary heart disease is absent. However, a recent report by James¹ emphasizes the clinical significance of abnormal changes in coronary arteries which are too small to be interpreted adequately even on optimal quality coronary angiograms. Diseases which may damage and occlude small coronary arteries can be classified in three broad categories: embolic, inflammatory, and noninflammatory. Diverse processes including coronary atherosclerosis, multiple platelet aggregation, postoperative particulate debris, and subacute bacterial endocarditis may be responsible for embolic occlusion of small coronary arteries with resultant alteration of cardiovascular function. Small coronary vessel arteritis has been demonstrated in inflammatory diseases such as polyarteritis nodosa, systemic lupus erythematosus, and rheumatoid arthritis. Finally the clinician must be alert to the possibility that noninflammatory disease can significantly affect small coronary arteries; in this group are such pathologic states as amyloidosis, hematologic disorders, diabetes mellitus,