Stress and cardiovascular disease: mechanisms and measurement.

Physiological overreactivity to mental stress has been correlated with the subsequent development of cardiovascular diseases. This coronary-prone behavior (referred to as "hot reacting") is distinct from the Type A behavior pattern and is seen in about 1 in 5 apparently healthy individuals. This paper describes a noninvasive system for measuring hemodynamics that can reveal the mechanisms raising the blood pressure of hot reactors or hypertensives. The subject is challenged with a variety of mental and physical stressors while the hemodynamic responses are monitored. Blood pressure elevations are found to be caused either by increased cardiac output, increased resistance, or a combination. Output reacting represents the early stage of hypertension. Beta blockers or even nonpharmacologic methods are generally effective in controlling the blood pressure. Combined reactors may benefit from a moderate dose of a beta-blocker and a vasodilator. The vasoconstrictive reactors are at greatest risk and require more extensive evaluation as well as vasodilatory therapy. Utilization of the hemodynamic profile permits adjusting treatment to the underlying physiologic state which reduces side effects and enhances compliance.