Psychosomatic elements, behavior, and sympathetic overactivity are presumed to 
underlie many cardiovascular diseases; the most investigated conditions are 
borderline hypertension and type A/B behavior. Many patients with borderline 
hypertension show signs of hyperkinetic circulation, that is, elevated heart 
rate and cardiac index. This elevation is neurogenic, since it can be abolished 
with a combination of beta-adrenergic and parasympathetic blockade. Response to 
such stepwise blockade shows a larger beta-adrenergic and a lower 
parasympathetic change in cardiac tone, characteristic of the functional 
organization of the medullary integrative centers of cardiovascular control. The 
most likely cause for this abnormal integration is psychosomatic. These patients 
may be expected to respond to treatment with behavioral and/or cardioselective 
beta-adrenergic blocking agents. There is little doubt that type A behavior is a 
predictor of coronary heart disease. The description of the pathophysiology of 
these transient but characteristically excessive cardiovascular episodes is 
difficult, however. Type A individuals do not always hyperreact in the same way; 
the response can be limited to heart rate, blood pressure, or occasionally 
exaggerated urinary or plasma catecholamine responses. In our laboratory we 
concentrated on steady markers of type A behavior. Type A subjects had 
reproducibly larger pupil size--indicative of increased sympathetic 
arousal--higher heart rate and diastolic blood pressure, and significantly 
elevated platelet epinephrine values when challenged by a mental task. Treatment 
with behavioral methods, beta-blocking agents, or both might be useful for 
prevention of coronary heart disease in type A individuals.