STRESS AND THE HEART
Prof. A.K. Srivastava
Consultant Heart Surgeon

At present there is a great emphasis in medicine on inherited personality traits in the development of various stress induced psychosomatic disease particularly with reference to the probability of coronary heart attack at an early age. All individuals have a characteristics manner of responding to an acute threat in keeping with the basic
disposition of the personality, but it is only in those who fail to repetitive or continued stress that sustained reaction may predispose to subsequent disease. While the fight or flight mechanism was apparently designed for short term emergency needs it appears that coronary prone subjects often possess homeostatic mechanism, which
remain chronically mobilized in response to the demands of a rapidly changing environment. By sustained general autonomic arousal such persons manifest a failure to master stress in continuum. From the resulting chronic activation of the defense centre in the brain (Hypothalamus) cholesterol levels in the blood are maintained at higher ranges, circulating catecholamines are present in increased concentration and clotting mechanism
are adversely affected. A high fat diet, cigarette smoking, lack of exercise and diabetes could readily exert a harmful influence by exaggerating certain components of these physiologic expression of fight or flight. Similarly, prolonged emotional stress, sociocultured mobility, or stressful life events could also bridge the gap between subclinical genetic predisposition and premature maturation of coronary artery disease.
Stress may be defined as the nonspecific response of body to any demand. It can be eustress (being agreeable or healthy) or distress (disagreeable or pathogenic) the way in which a certain stimulus will be received depends on its intensity and particular receptiveness of the affected persons. This diversity depends primarily on conditioning (Production of hormones). All stressors must necessary have some specific effects of their
own that they can not always elicit the same response. In fact, even the same stimulus will act differently in different individuals depending on endogenous conditioning factors (genetic predisposition, age, sex) or exogenous (treatment with hormones, drugs and exposure to environmental factors including air pollution and social influence.
Coronary artery disease is more common in “stress seekers” the “race horse” type as opposed to the easy going “turtle type” individuals. In their classic studies, Fridman & Rosenman refer to these as “Type A” and “Type B” persons, the former being particularly prone and the latter resistant to untimely coronary accidents during early middle age. Type A personality who is most likely to develop coronary artery disease is characterized by:
1. An intense sustained drive to achieve self selected But usually poorly defined goals
2. Profound inclination and eagerness to complete
3. Persistent desire for recognition and advancement
4. Continuous involvement in multiple and diverse functions constantly subject to time restrictions
5. Habitual propensity to accelerate the rate of execution of many physical and mental functions
6. Extraordinary mental and physical alertness.
How does emotional stress cause coronary heart disease Emotion has long been thought to be relevant to the cause of coronary heart disease and to the occurrence of acute cardiac events. It enhances sympathetic activity via
intermediary pathway through brain (hypothalamus) resulting into liberation of hormones such as adrenaline and noradrenaline. These hormones result into mobilization of free fatty acids (FFA) from fatty tissue which ultimately get converted into triglycerides and cholesterol. Finally triglycerides and cholesterol are incorporated into atheroma (blockade in coronary artery). Blocked coronary artery causes reduction in blood supply to the heart.
Emotional stress further causes increase in heart rate and blood pressure thereby increases myocardial oxygen demand. An imbalance therefore exists between supply and demand ratio which ultimately result, into angina and heart attack. If untreated death ensues