Atherosclerosis in all probability has no single cause. Among those factors presently implicated are (1) heredity, (2) diet, (3) anatomy of the blood vessel wall, (4) arterial blood pressure, (5) lipid content of the blood, and (6) sex. Because atherosclerosis is a focal lesion, its consequences are widely variable. There is no practical means of clinical diagnosis of uncomplicated, potentially reversible lesions. The approach to this problem by animal experiments has shown that atherosclerosis which is closely similar to, but not necessarily identical with, the human type can be produced in a variety of experimental animals by dietary variations. The results of such experiments have had a significant influence on the opinions of many clinicians.
The clinical diagnosis of coronary arterial heart disease dates substantially from the first decade of this century. No one questions the remarkable increase in the reported number of cases of this condition. Undoubtedly the wide