Behavioural-cardiac interactions: the psychosomatic hypothesis

Cognitive stress and cardiovascular reactivity. II. Relationship to atherosclerosis, arrhythmias, and cognitive control

This is the second of a two-part series on the effects of cognitive stress on cardiovascular disease. This paper reviews the relationship between cognitive stress and cardiovascular reactivity as it relates to the development of atherosclerosis and arrhythmias. In addition, the moderation of cardiovascular reactivity by the opportunity to exercise control over the stressor is discussed. The findings may be summarized as follows. First, recent animal work has suggested that the magnitude of heart rate change in the presence of a conditioned aversive stimulus is positively correlated with the extent of coronary atherosclerosis under diets high and low in atherogenic potential. Second, cardiovascular reactivity in humans may be related to several factors that could have an influence on the pathogenesis of atherosclerosis. These factors include: increased beta-adrenergic driving, increased shearing force on the intimal lining of the vessels, changes in pulsatile flow and the subsequent smooth muscle reparatory process. Cognitive (psychological) stress has also been related to ST segment depression, rate-pressure product changes, and changes in cardiac contractility. Animal studies have shown that the susceptibility to ventricular fibrillation may be enhanced by the presence of a conditioned aversive stimulus and may be reduced through adaptation to the aversive environment. The balance between sympathetic and parasympathetic influences on the myocardium may also play a critical role in the susceptibility of an already diseased heart to succumb to fatal arrhythmias during a behavioral stressor. Finally, studies in which subjects may exercise some control over an aversive stimulus suggest that cardiovascular reactivity may be pronounced and sustained in situations requiring frequent adjustment to changes in the criteria for successful performance, and/or the presence of positive incentives.

Hypertension, disclosure of personal concerns, and blood pressure response

Studied the degree of self-disclosure in borderline and hypertensive individuals (N = 50) using a checklist of personal concerns. Shoppers who sought blood pressure measurements in a health display had blood pressure measured before and after the completion of the checklist. Results showed that individuals with elevated blood pressure did not disclose as many personal concerns as normotensives and were less likely to report feeling stressed after the cognitive task even when blood pressure increases had occurred. These findings indicate the need both for further understanding of the nature of self-disclosure and also concurrent investigations of hypertensive characteristics and blood pressure responsivity.

Family history of hypertension, gender, and cardiovascular reactivity and stereotypy during stress

Thirty subjects with a family history of hypertension and 28 subjects without such a history performed a Stroop Color-Word Interference task, a mental arithmetic task (serial subtraction of sevens), and a shock avoidance task (repeating digits backward while expecting to be shocked for mistakes). Systolic and diastolic blood pressure and pulse rate were recorded while subjects anticipated, undertook, and recovered from the shock avoidance task and undertook and recovered from the Stroop and mental arithmetic tasks. It was found that compared to nonfamily history subjects, family history subjects manifested reliably greater cardiovascular reactivity during each task and in anticipation of the shock avoidance task. These results are congruent with the notion that excessive sympathetic nervous system reactivity-possibly genetically determined-is involved in the development of some form of essential hypertension. Further, the results indicated that family history subjects manifested greater consistency, or stereotypy, of cardiovascular response across the experimental tasks than nonfamily history subjects. The possible role of cardiovascular stereotypy in the development of essential hypertension is also discussed.