Physiologic reactions to social challenge in persons evidencing the type A coronary-prone behavior pattern.

Physiologic measures were recorded in Type A1 (n = 10) and Type B (n = 14) subjects while they engaged in a reaction-time task after receiving instructions emphasizing the need for rapid and accurate performance. Although resting levels were not significantly different, Type A's responded with significantly greater increases than B's in both heart rate and systolic blood pressure, suggesting greater sympathetic arousal. A significant baseline difference between the Types in heart rate variability was also observed suggesting greater lability in sympathetic-parasympathetic function in Type A's. No differences between the Types were obtained for either galvanic skin potential (GSP) or speed of reaction. It is suggested that the paradigm used in the present study offers an inexpensive and efficient means by which cardiovascular reactivity in Type A's and B's may be explored in other and larger groups of subjects.