Hostility, gender, and cardiac autonomic control

Objective: Although considerable evidence implicates hostility in the devel opment of coronary artery disease (CAD), the pathogenic mechanisms remain p oorly understood. We have developed a psychophysiological model that holds that altered autonomic nervous system function links psychological traits w ith CAD outcomes, In Laboratory studies, stressors reduce high-frequency (H F) heart period variability, an index of cardiac vagal modulation. With amb ulatory electrocardiographic recording, we demonstrated in a predominantly male sample that hostility was inversely associated with HF power, but only during waking hours. These findings are consistent with the hypothesis tha t hostile individuals experience multiple stressful interpersonal transacti ons each day, resulting in overall lower HF power during the day but not at night. Methods: To further evaluate this hypothesis, we screened 96 subjec ts using the Cook-Medley Hostility Scale and selected 15 men and 15 women r epresenting a wide distribution of hostility. These subjects were studied i n a laboratory session assessing reactivity to psychological and orthostati c challenges with continuous electrocardiographic, blood pressure, and resp iration monitoring. We predicted that for men and women, hostility would be inversely related to reductions in HF power in response to challenge. Resu lts: In response to mental stressors, all measures of heart period variabil ity change were inversely related to hostility as predicted, No such relati onships were found for responses to tilt, The data suggested a possible eff ect of gender on these relationships, Conclusions: These data add to the gr owing body of evidence showing that hostility influences vagal modulation o f the cardiovascular system and suggest that altered autonomic control is a pathogenic mechanism linking hostility and CAD.