ABSTRACT
Stress-induced changes in blood pressure (BP) and heart rate (HR) provide useful indices of autonomic nervous system activity (Krantz & Manuck, 1984). The autonomic nervous system (ANS) is intimately involved in the body’s responses to environmental challenges such as physical activity and mental arousal. An extensive body of literature also exists demonstrating adverse short-term and long-term pathophysiological consequences of increases in ANS activity (Kop, 1999; Krantz et al., 1996; Williams et al., 1991). The ANS, which regulates activity of the cardiac muscle, glands, and smooth muscles, is divided into two efferent components: the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). These two components of the ANS are involved in hemodynamic responses to physical and emotional stressors by direct nervous control of the blood vessels and heart muscle as well as indirect neurohormonal regulation of the cardiovascular system. The current scientific and lay literature emphasizes the effects of chronic and acute stress on the development of cardiovascular disorders such as hypertension and coronary artery disease. Increased activation of the SNS may result in adverse health outcome by directly affecting the pathophysiological processes responsible for disease progression (e.g., accelerated atherosclerosis) and in addition by elevating the workload of the cardiovascular system (e.g., increased BP). Measures of BP and HR responses to mental arousal may reveal important information about the pathophysiological mechanisms of stress-induced cardiovascular events and may improve the risk-stratification for adverse cardiovascular health outcome (Krantz et al., 1996). Therefore, cardiovascular measures are important and widely-used measurement tools employed in behavioral medicine research.
