[Stress and the cardiovascular system].

A variety of evidence shows that stress contributes to a more or less sustained elevation of blood pressure, as well as to the triggering and aggravation of cardiovascular pathology, especially coronary heart disease. Experimentally induced changes, that may be pathogenic due to their duration or repetition, can be produced in hemodynamics, lipid metabolism, or hemostasis. High blood pressure, vascular heredity, but also a trend to inhibition of action, seem to be responsible for hyperreactivity to stress. Hypertensives are particularly reactive to active stresses related to controlable situations, experienced as challenges. Several prospective studies in healthy subjects have confirmed the increased risk for coronary heart disease of certain psychological characteristics: the most known of them is Rosenman's and Friedman's type A behavior (hyperactivity, speed and impatience, hard driving, job involvement). It is known that individuals presenting such characteristics exhibit increased neuroendocrine responses to all types of stress. Pattern A predicts the incidence of myocardial infarction, independently of other coronary risk factors, such as hypertension, hypercholesterolemia, or smoking habits. It as been proved that type A individuals deal on average with more stressing conditions than type B individuals and that they set higher goals than general population. On a cognitive level, they tend to have an internal "locus of control" (they are inclined to attribute their personal successes or failures to their own responsibility). Nevertheless, the most reactive to stress among type A individuals are those whose locus of control is external. The predictive validity of pattern A in coronary mortality is more debated.(ABSTRACT TRUNCATED AT 250 WORDS)