Plasma catecholamine response of coronary-prone subjects (type A) to a specific challenge.

Plasma norepinephrine (NE) and epinephrine (E) were assayed in 15 men prone to develop coronary heart disease (type-A behavior pattern) and in 15 coronary-disease-resistant men (type-B behavior pattern) under resting, noncompetitive conditions and also immediately before, during, and after participation in a nonphysical competitive struggle. The average concentration of catecholamines was virtually the same in both groups under resting conditions. Under competitive conditions the NE concentration of the coronary-susceptible group rose an average of 30%, while that of the resistant group remained essentially unchanged. E concentration remained unchanged in both groups.