ive of

Background: Human beings throughout the world are faced with high and ever increasing levels of acute or chronic stress. Acute stress is defined as “the normal short-term physiological response to the perception of major threat or demands”. Chronic stress is defined as “the abnormal ongoing physiological response to the continuing perception of irresolvable major threats or demands”.1 In fact, all these modern definitions of stress date back to the time of Hans Selye, the first scientist who studied the effects of stress on health and physiological integrity of living organisms.2 Accordingly, the term stress pertains to effects of all environmental and psychosocial factors on physical or mental well-being.1 The effect of stress on cardiovascular system ha