Cardiovascular diseases comprise especially the major disorders of the heart and the arterial circulation supplying the heart, brain, and peripheral tissues. Their common occurrence in most populations and the great attendant mortality, loss of independence, impaired quality of life, and social and economic costs are compelling reasons for public health concern. Theepidemiology and prevention of these diseases involve the understanding of their causes, identification of means of prevention, and monitoring of populations to assess the changing burden of these diseases and the measurable impact of interventions to control them. Together, the cardiovascular or circulatory diseases have figured prominently in the large shifts among causes of death, especially in industrial societies, during the 20th century.