It is apparent that a variety of factors may be responsible for myocardial ischemia, and even infarction, in the absence of occlusive major vessel coronary disease. In particular, it must be emphasized than angina-like chest pain may well have its origin in myocardial ischemia, even in younger patients with unusual patterns of chest pain but without predisposition to premature CAD. Increasing awareness of disorders such as coronary arterial spasm, functional impairment of subendocardial blood flow and the possible role of variant patterns of anatomic distribution of the coronary arterial tree, will provide a better understanding of their significance as determining or contributing factors in patients with the anginal syndrome.