Effect of harassment and competition upon cardiovascular and plasma catecholamine responses in type A and type B individuals

Effects of Cybersickness Caused by Head-Mounted Display-Based Virtual Reality on Physiological Responses: Cross-sectional Study

Background

Although more people are experiencing cybersickness due to the popularization of virtual reality (VR), no official standard for the cause and reduction of cybersickness exists to date. One of the main reasons is that an objective method to assess cybersickness has not been established. To resolve this, research on evaluating cybersickness with physiological responses that can be measured in real time is required. Since research on deriving physiological responses that can assess cybersickness is at an early stage, further studies examining various physiological responses are needed.

Objective

This study analyzed the effects of cybersickness caused by head-mounted display–based VR on physiological responses.

Methods

We developed content that provided users with a first-person view of an aircraft that moved (with translation and combined rotation) over a city via a predetermined trajectory. In the experiment, cybersickness and the physiological responses of participants were measured. Cybersickness was assessed by the Simulator Sickness Questionnaire (SSQ). The measured physiological responses were heart rate, blood pressure, body temperature, and cortisol level.

Results

Our measurement confirmed that all SSQ scores increased significantly (all Ps<.05) when participants experienced cybersickness. Heart rate and cortisol level increased significantly (P=.01 and P=.001, respectively). Body temperature also increased, but there was no statistically significant difference (P=.02). Systolic blood pressure and diastolic blood pressure decreased significantly (P=.001).

Conclusions

Based on the results of our analysis, the following conclusions were drawn: (1) cybersickness causes significant disorientation, and research on this topic should focus on factors that affect disorientation; and (2) the physiological responses that are suitable for measuring cybersickness are heart rate and cortisol level.

Not All Competitions Come to Harm! Competitive Biofeedback to Increase Respiratory Sinus Arrhythmia in Managers

Despite the positive impact on achievement, competition has been associated with elevated psychophysiological activation, potentially leading to a greater risk of cardiovascular diseases. Competitive biofeedback (BF) can be used to highlight the effects of competition on the same physiological responses that are going to be controlled through BF. However, it is still unknown whether competition could enhance the effects of respiratory sinus arrhythmia (RSA)-BF training in improving cardiac vagal control. The present study explored whether competitive RSA-BF could be more effective than non-competitive RSA-BF in increasing RSA in executive managers, who are at higher cardiovascular risk of being commonly exposed to highly competitive conditions. Thirty managers leading outstanding private or public companies were randomly assigned to either a Competition (n = 14) or a Control (n = 16) RSA-BF training lasting five weekly sessions. Managers in the Competition group underwent the RSA-BF in couples and each participant was requested to produce a better performance (i.e., higher RSA) than the paired challenger. After the training, results showed that managers in the Competition group succeeded in increasing cardiac vagal control, as supported by the specific increase in RSA (p < 0.001), the standard deviation of R-R wave intervals (SDNN; p < 0.001), and root mean square of the successive differences between adjacent heartbeats (rMSSD; p < 0.001). A significant increase in the percentage of successive normal sinus beat to beat intervals more than 50 ms (pNN50; p = 0.023; η2 p = 0.17), low frequency (p = ≤ 0.001; η2 p = 0.44), and high frequency power (p = 0.005; η2 p = 0.25) emerged independently from the competitive condition. Intriguingly, managers who compete showed the same reduction in resting heart rate (HR; p = 0.003, η2 p = 0.28), systolic blood pressure (SBP; p = 0.013, η2 p = 0.20), respiration rate (p < 0.001; η2 p = 0.46), and skin conductance level (SCL; p = 0.001, η2 p = 0.32) as non-competitive participants. Also, the same reduction in social anxiety (p = 0.005; η2 p = 0.25), state (p = 0.038, η2 p = 0.14) and trait anxiety (p = 0.001, η2 p = 0.31), and depressive symptoms (p = 0.023, η2 p = 0.17) emerged in the two groups. The present results showed that managers competing for increasing RSA showed a greater improvement in their parasympathetic modulation than non-competing managers. Most importantly, competition did not lead to the classic pattern of increased psychophysiological activation under competitive RSA-BF. Therefore, competition could facilitate the use of self-regulation strategies, especially in highly competitive individuals, to promote adaptive responses to psychological stress.

Biochemical Measurements in the Study of Emotion

The study of emotions is complicated by a number of factors, including the biological bases of emotional experience and expression. Although biochemical changes have long been thought to be part of the evocation of emotions, research has not consistently included this level of measurement, and theories of emotion have not systematically specified the role of these biochemical bases. In this paper, we briefly review relevant biochemical principles and measures that can be integrated into research and theory on emotions. Applications of these principles in extant studies of emotion are also discussed.

Individual Differences in Physiological Responses to Fearful, Racially Noxious, and Neutral Imagery

Mental imagery has recently emerged as an alternative to traditional laboratory stressors in psychophysiological studies. The present study assessed physiological responsivity to fearful, neutral, and racially noxious image scenes in sixty-two black women. In addition, the utility of several personality variables for predicting physiological changes in response to the scenes was assessed. Thirty-one vivid and thirty-one non-vivid imagers participated in a preliminary session during which they were given progressive relaxation training and were instructed to image an event on cue. On a separate occasion physiological responses to the scenes were assessed. Findings indicated that the fearful and racially noxious scenes elicited comparable increases in corrugator and heart rate activity. The neutral scene had a less pronounced effect on heart rate and corrugator activity than the other scenes. Results of multiple regression analyses in which personality variables served as predictors of physiological activity revealed that certain dimensions of the Type A coronary prone behavior pattern and trait anxiety were significant predictors of physiological reactivity. These predictors were most effective where a conceptual link between the content of the scenes and the specific dimensions was identifiable. The results suggest that the imagery paradigm is useful for studying the effects of complex social stressful situations akin to those growing out of racism. They also underscore the potentially facilitory role personality assessment may have in pinpointing sources of variability in response to this form of laboratory stress.

Denial of Depression as an Independent Correlate of Coronary Artery Disease

A number of psychosocial measures were tested as correlates of coronary artery disease (CAD) in 122 males with positive coronary angiograms and 56 males with no manifest history of atherosclerotic disease who were selected to approximate the patients' age and socio economic status. Only denial of depression as indexed by spouse/friend-minus-self scores on the Ketterer Stress Symptom Frequency Checklist and number of unprovoked nocturnal awakenings were independently and positively related to CAD severity in multivariate regression analyses which controlled for jointly associated cardiac risk factors and commonly used cardiovascular medications. Denial of depression and unprovoked nocturnal awakening appear to be independent correlates of coronary artery disease.

Colony social stress differentially alters blood pressure and resistance-sized mesenteric artery reactivity in SHR/y and WKY male rats

Increased sympathetic nervous system (SNS) activity, testosterone, and spontaneously hypertensive rat Y chromosome (SHR Yc) play a role in a genetic model of hypertension. Male rats with the SHR Yc and Wistar-Kyoto (WKY) autosomes (denoted SHR/y) exhibit these characteristics when compared to rats with the WKY Yc and WKY autosomes (denoted WKY). We hypothesized that chronic social stress will increase blood pressure and SNS activity more in SHR/y males compared to WKY males, resulting in increased myogenic reactivity along with decreased vasoconstriction of small mesenteric arteries. SHR/y and WKY males were housed in strain- specific colonies (10 males with 10 females) or as controls (10 males). Systolic blood pressure (SBP) and blood samples were collected prior to termination. Second-order mesenteric arteries were studied using a pressure arteriograph in which myogenic reactivity and phenylephrine (PE) responsiveness were measured. SHR/y colony SBP, and circulating norepinephrine and testosterone concentrations were elevated compared to control and WKY colony males (p < 0.05). Mesenteric artery myogenic reactivity was increased in SHR/y colony males (p < 0.001). Mesenteric arteries from SHR/y colony males exhibited a significant decrease in PE-induced constriction. Colony social stress elevated both SNS activity and testosterone level which may be responsible for the increased mesenteric artery myogenic reactivity, and SBP as noted in SHR/y males.

Psychological and physiological responses of individuals displaying type A behaviour

Earlier findings on the relationship between the coronary-prone behaviour pattern Type A and coronary heart disease (CHD) are briefly reviewed, with particular reference to the underlying pathophysiological mechanisms linking the two. Results obtained during the playing of competitive games with or without harassment from the opponent suggest that competition alone does not distinguish between Type A and Type B individuals. The Type A pattern appears to be associated with exaggerated cardiovascular responses only as the result of hostile interactions. The primary need to study the Type A pattern as psychological construct is emphasized. Analysis of structured interview responses suggests that hostility and competitive drive are the two components of the pattern associated with cardiovascular disease. A model is proposed in which Type A subjects, faced with threats of their control, exhibit first hyper-responsive and then hypo-responsive efforts to regain it, and experimental evidence in support of this model is presented. However, such hyper-responsive reactions might be linked more closely to coping and defence mechanisms than they are to Type A. It is proposed that the Type A pattern be regarded as an aspect of the person-situation interaction and that efforts be made to establish those classes of environmental stimuli likely to elicit it.

Bio-behavioural perspectives on coronary heart disease, hypertension and sudden cardiac death

A series of research developments is described which together consider the problem of the relationships between behavioural, physiological and pathophysiological processes. Arguments are advanced for the measurement of challenge-induced changes in haemodynamic responses for use in the understanding, prediction and control of coronary heart disease (CHD), hypertension and sudden cardiac death. A methodology is presented as a possible tool for accomplishing this latter goal and preliminary data are reported in support of the feasibility of these methods. Finally, basic pathophysiological mechanisms in cardiovascular disorders are examined in relation to potentially damaging haemodynamic activity.

Effects of Milk Casein-derived Peptides on Absolute Oxyhaemoglobin Concentrations in the Prefrontal Area and on Work Efficiency after Mental Stress Loading in Male Students

This study examined the influence of milk casein-derived peptides on cerebral activity after mental stress loading. In a crossover study, 16 male students were given a drink containing peptides (peptide group), or water (control group) before stress loading. The oxyhaemoglobin (HbO2) concentration in the prefrontal area of the brain and work efficiency were measured as indicators of cerebral activity and differences in these parameters were examined according to type A or type B personality. Type A behaviour was defined as: aggression–hostility, hard-driving—time-urgency and speed–power, whereas type B behaviour did not have these characteristics. Peptide intake resulted in a significant increase in both HbO2 concentration and work efficiency, whilst a similar increase was not seen in the control group. When divided into type A or type B personality, the changes in HbO2 concentration for the control group differed significantly in the right prefrontal area. Moreover, in type A subjects the HbO2 concentration in the right prefrontal area following intake was significantly different between the peptide and control groups.

Mental stress and coronary artery disease: a multidisciplinary guide

Research suggests that acute and chronic stress are risk factors for the development and progression of coronary artery disease. Much of this work is multidisciplinary, using unfamiliar concepts deriving from disciplines other than cardiology and medicine. This article addresses and clarifies, for the cardiologist, some of the key concepts and issues in this area and provides an overview of evidence linking acute and chronic stress to cardiac pathology. Areas addressed include definitions and measurement of mental stress, methodological issues in stress research, and distinctions between stress and variables such as personality, emotion, and depression. Mental stress is a multifactorial process involving the environment, individual experiences and coping, and a set of neuroendocrine, autonomic, cardiovascular, and other systemic physiologic responses. There are difficulties identifying a single consensus physiologic stress measure because of individual differences in perceptions and physiologic response patterns. Nonetheless, important associations exist between mental stress and clinically relevant cardiovascular end points. As multidisciplinary research in this area continues, one major goal is the better integration of psychosocial knowledge and measures with cardiology research and practice.

Individual differences in cardiovascular response to social challenge

An important determinant of cardiovascular stress reactivity and morbidity is the individual behavioral strategy of coping with social challenge. This review summarizes the results of a number of studies that we performed in rats, aimed at investigating the relationship between aggression and cardiovascular responsivity under social stress conditions. We show that rats belonging to the 'aggressive tail' of a population are characterized by a higher sympathetic-adrenomedullary activation during social and non-social stress episodes. Wild-type rats are characterized by a larger sympathetic dominance and a higher susceptibility to cardiac arrhythmias during defeat as compared to Wistars. Cardiovascular habituation takes place when social challenge is an intermittent victory experience, whereas no habituation is observed across repeated defeat episodes. Dominant rats whose social dominance is challenged by the aggression of another subject display long-term alterations of heart rate circadian rhythmicity. Such changes are linked to individual proness to defend social dominance: the more the animal counterattacks the aggressor, the smaller the subsequent rhythm disturbance. These data underline how important it is to carefully consider individual differences in aggression and the context in which aggression is expressed, when studying cardiovascular effects of social interactions.

Relative effects of harassment, frustration, and task characteristics on cardiovascular reactivity

Effects of anger induction procedures such as frustration and harassment on cardiovascular reactivity have been demonstrated in a wide range of experimental situations. Similarly, heightened cardiovascular reactivity has been associated with a diverse range of tasks involving active coping, competition and interpersonal interaction. The present study sought to directly compare the relative effects of these two important ways of inducing cardiovascular changes. One hundred and five university students performed two tasks that differed in the degree of active coping and interpersonal competition: a competitive psychomotor task and a problem-solving task. States of anger were induced during both tasks by means of harassment, frustration or frustration+harassment. Task-related changes in heart rate, systolic blood pressure, diastolic blood pressure, pulse volume amplitude and respiratory sinus arrhythmia amplitude were monitored. The competitive psychomotor task produced greater cardiovascular reactivity than did the problem-solving task. Harassment and frustration+harassment provoked more cardiovascular reactivity than did frustration alone. However, harassment and frustration+harassment had the greatest cardiovascular effects in the competitive task, whereas frustration had the greatest cardiovascular effects in the problem-solving task. In this sense, the increases on cardiovascular reactivity seem to depend on the interaction between anger induction procedures and the context in which anger is provoked.

Cardiac autonomic reactivity and salivary cortisol in men and women exposed to social stressors: relationship with individual ethological profile

The degree of cardiovascular stress responsivity and its possible implications for the onset and progression of cardiovascular pathologies seem to be linked to the individual strategy of behavioral coping with stressors. This study was designed to investigate the relationship among cardiac autonomic, endocrine and behavioral responses to real-life stress episodes. Thirty university students were exposed to two brief social challenges (stress interviews), during which the state of sympathovagal balance (time-domain indexes of heart rate variability) and a number of non-verbal behaviors were quantified. Psychometric measurements were also obtained via SPRAS questionnaire, administered just after each stress interview. Samples of saliva were collected for cortisol determination immediately prior and after the experimental session. Subjects showing higher levels of sympathetic dominance were characterized by higher scores of submissive behavior, larger cortisol increments, and higher perception of psychophysiological arousal. A clear consistency in the individual response to the two stress interviews was found, at the behavioral, physiological and psychophysiological level. Finally, the gender of the subjects did not clearly influence their stress responsivity. These results support the hypothesis of a close relationship between the degree of physiological arousal and the style of behavioral adaptation to social stressors.

The influence of Type A behavior pattern on the response to the panicogenic agent CCK-4

OBJECTIVES

Review of the literature equivocally suggests that subjects with Type A behavioral pattern (TABP) compared to subjects with Type B behavioral pattern display an increased sympathetic activity, a condition associated with sudden cardiac death. The objective of this study was to determine whether healthy subjects classified as Type A or Type B differed in their reactivity to the beta 1 and beta 2 receptor agonist isoproterenol and to the panicogenic agent cholecystokinin-tetrapeptide (CCK-4). By comparing reactivity to CCK-4 after pretreatment with placebo or propranolol, a beta 1 and beta 2 receptor antagonist, the role of the beta adrenergic system in the hypothesized increased response of Type A subjects to CCK-4 was also assessed.

METHODS

The study used a randomized, double-blind, placebo-controlled design. Twenty-seven Type A or B subjects were included in the study. The reactivity to isoproterenol was assessed with the CD25 of isoproterenol (i.e., the intravenous dose of isoproterenol necessary to increase the heart rate of 25 bpm). The panic symptom response and the cardiovascular response to bolus injection of 50 microg of CCK-4 was assessed in subjects pretreated with either propranolol or placebo infusions prior to the CCK-4 challenge. An additional group of subjects was recruited and these subjects received a placebo infusion pretreatment before an injection of placebo.

RESULTS

The CD25 was significantly greater in Type A subjects than in Type B subjects. No difference was found among the groups on behavioral sensitivity to the CCK-4 challenge. However, CCK-4-induced maximum increase in heart rate was greater in Type A subjects.

CONCLUSION

Our finding that Type A subjects exhibited greater CD25 of isoproterenol and greater increases in heart rate following CCK-4 administration compared to Type B subjects suggests that peripheral beta-receptor sensitivity may be increased in individuals with TABP.

Hostility, gender, and cardiac autonomic control

OBJECTIVE

Although considerable evidence implicates hostility in the development of coronary artery disease (CAD), the pathogenic mechanisms remain poorly understood. We have developed a psychophysiological model that holds that altered autonomic nervous system function links psychological traits with CAD outcomes. In laboratory studies, stressors reduce high-frequency (HF) heart period variability, an index of cardiac vagal modulation. With ambulatory 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 that hostile individuals experience multiple stressful interpersonal transactions each day, resulting in overall lower HF power during the day but not at night.

METHODS

To further evaluate this hypothesis, we screened 96 subjects using the Cook-Medley Hostility Scale and selected 15 men and 15 women representing a wide distribution of hostility. These subjects were studied in a laboratory session assessing reactivity to psychological and orthostatic challenges with continuous electrocardiographic, blood pressure, and respiration monitoring. We predicted that for men and women, hostility would be inversely related to reductions in HF power in response to challenge.

RESULTS

In response to mental stressors, all measures of heart period variability change were inversely related to hostility as predicted. No such relationships were found for responses to tilt. The data suggested a possible effect of gender on these relationships.

CONCLUSIONS

These data add to the growing body of evidence showing that hostility influences vagal modulation of the cardiovascular system and suggest that altered autonomic control is a pathogenic mechanism linking hostility and CAD.

Effects of emotional imagery on physiological and facial responses in Type A and Type B individuals

Type A behavior was examined in relation to physiologic and facial-expressive changes associated with anger, fear and distress. Affect was induced by an imagery procedure in which subjects recalled and described actual, emotion-related episodes. Type A was assessed by a structured interview. Subjects were healthy men, 21 Type As and 21 Type Bs, whose mean age was 39 yr. Type Bs showed higher systolic blood pressure responses and greater expression of negative affect than Type As. Data analysis also revealed a tendency for enhanced physiologic and facial responses of Type Bs relative to Type As to be greater during fear and distress than during anger. These results appear to reflect a coping process whereby Type A individuals show attenuated facial-expressive and physiologic reactivity as a means of maintaining a sense of control over aversive conditions.

Influence of exogenous melatonin on catecholamine levels in postmenopausal women prior and during oestradiol replacement

OBJECTIVE

In young individuals melatonin administration reduces circulating norepinephrine. Some effects of melatonin are reduced in elderly women and are modulated by gonadal steroids. Accordingly, the influence of melatonin on catecholamine levels was investigated in postmenopausal women without and with oestradiol replacement.

DESIGN

Prior to and after 2 months of transdermal oestradiol (50 microg/day), women were studied on two consecutive days, on which they received placebo or 1 mg of melatonin orally in a randomised and double-blind fashion.

PATIENTS

Fourteen healthy postmenopausal women.

MEASUREMENTS

Resting levels of epinephrine and norepinephrine and their responses to both a cold stimulus, performed by placing a hand in a basin of water and ice for 2 minutes, and to 10 minutes of upright position (upright test).

RESULTS

Prior to oestradiol, melatonin did not modify baseline or stimulated catecholamine levels. In contrast, during oestradiol, melatonin tended to reduce, although not significantly, baseline norepinephrine levels (P = 0.053), and significantly reduced peak values (P = 0.0061) and integrated norepinephrine response (P = 0.0076) to the cold stimulus. Responses of norepinephrine to the upright test were not modified, while those of epinephrine were increased (P = 0.042). During, but not prior to oestradiol replacement, modifications induced by melatonin (melatonin day-placebo day) in the norepinephrine response to the cold (r2 = 0. 457; P = 0.0079) and the upright (r2 = 0.747; P = 0.0001) tests were linearly and inversely related to the responses of the placebo day.

CONCLUSIONS

Melatonin does not modulate adrenergic activity in postmenopausal women without hormone replacement therapy. Oestradiol replacement restores the capability of melatonin to modulate adrenergic activity, particularly the norepinephrine response to stimuli.

Individual differences in physiological responses and type A behavior pattern

The relationships between individual differences in psychophysiological responses and tendency of Type A behavior pattern (TABP) were investigated during mental arithmetic (MA) at a steady rhythm, challenging calculation (Uchida-Kraepelin serial addition test: UK test), music listening, and exposure to an 80 dB SPL of white noise. Each mental task was sustained for 5 minutes. Sixteen healthy Japanese adults, (10 males and 6 females) with an age from 18 to 36 years old volunteered for this study. The KG's Daily Life Questionnaire (KG Questionnaire) was used to investigate the tendency toward TABP, which included three sub-factors: aggression-hostility, hard-driving and time urgency, and speed-power items. Recorded physiological variables were respiratory rate (RR), skin resistance response (SRR), eyeblinks, and heart rate (HR) calculated using frequency analysis to render high frequency power (HF) and the ratio of low/high frequencies (L/H ratio). During the MA and UK tests, significant increases in HR, L/H ratio, RR occurred, while significant decreases in HF were observed. Eyeblinks significantly increased during the MA test and significantly decreased during the UK test. During music and white noise, no significant changes occurred except for SRR, which decreased significantly. The coefficient of variances in each response was over 20% for almost all variables, indicating that individual differences in the magnitude of each response were large, even if the direction (increase or decrease) of the change was the same in almost all subjects. The highest correlation coefficients (r) between the mean values of relative magnitude for each variable and TABP scores during the MA and UK tests were obtained for the L/H ratio (MA: r = 0.591, UK test: r = 0.577) and the RR (MA: r = -0.576, UK test: r = -0.511). These values were statistically significant (p < 0.05). Similar results were obtained for TABP sub-factors. Though other investigations have reported relationships between HF and TABP, we found no significant relationship. It was suggested that sympathetic nerve activity became greater for TABP individuals than for Type B individuals under stress conditions.

Cardiac autonomic control buffers blood pressure variability responses to challenge: a psychophysiologic model of coronary artery disease

This article presents a model that identifies effects of blood pressure variability (BPV) as a possible mechanism by which psychological/psychiatric factors and health behaviors confer increased risk of coronary artery disease (CAD) and acute coronary syndromes. Recent research in vascular biology and dynamics of coronary artery blood flow suggests that BPV may have pathogenic effects on the coronary endothelium, plaque formation, and plaque stability. Thus, BPV may be a risk factor for cardiovascular disease independent of mean arterial pressure. The model proposes that autonomic control of the heart exerts a buffering or inhibitory influence on oscillations in blood pressure. Established psychological/behavioral risk factors for CAD, such as depression, hostility, and anxiety, as well as physical deconditioning and aging, are associated with diminished autonomic control of the heart, which may disinhibit pathogenic BPV. Together, these data suggest a coherent, testable psychophysiological model of CAD. In this article, we review these data and make recommendations for research to examine the model.

Effect of desogestrel-containing oral contraceptives on vascular reactivity and catecholamine levels

The modifications induced by new oral contraceptives (OC) on blood pressure, great vessel vascular reactivity by color Doppler, and catecholamine levels were investigated. Young healthy women not taking OC (n = 22; controls) or receiving, for > or = 6 months, OC containing desogestrel with either 30 micrograms (n = 14) or 20 micrograms of EE (n = 8) were enrolled. Blood pressure measured at rest in supine position was similar between controls and OC users. The pulsatility index (PI), an indirect index of resistance to blood flow, of axillary artery was significantly higher (p < 0.05) in 30 micrograms than in 20 micrograms EE OC users or controls. A similar trend, albeit not significant, was observed for the internal carotid artery PI. Norepinephrine (p < 0.01) and dopamine (p < 0.05) but not epinephrine levels, were lower in 30 micrograms EE OC users than in 20 micrograms EE OC users or controls. Thus, both 20 micrograms and 30 micrograms EE OC had no negative effect on blood pressure, but the 30 micrograms EE OC tended to increase great vessel resistance to blood flow, independently of catecholamine levels.

Association between cardiac autonomic function and coping style in healthy subjects

The link between personality and cardiac function is insufficiently characterized. We postulated that in a healthy population, cardiac autonomic function is linked to coping style. In 276 healthy volunteers, between the ages of 18 and 71, the Utrecht Coping List was used to evaluate different coping strategies. Trait anxiety was scored by the Spielberger State Trait Anxiety Inventory. A 24-hour Holter recording was used to calculate heart rate variability (HRV). For HRV parameters and coping mechanisms this study demonstrated gender-specific differences and correlations with age. In men (n = 141) higher active coping was associated with less global autonomic activity or SDANN (rs = -0.27, P < 0.001). This relationship was most prevalent in young (18-30 years) men (rs = -0.45, P < 0.005). Higher expression of negative emotions or anger was related to both higher vagal (rs = 0.23 for rMSSD, P < 0.01) tone and higher LF power (rs = 0.23, P < 0.01). In young men expression of negative emotions or anger was associated with LF power (rs = 0.37, P < 0.01) and in middle-aged (31-50 years) men with vagal tone (rs = 0.43 for rMSSD, P < 0.005) and heart rate (rs = -0.41, P < 0.005). Higher comforting ideas was related to higher LF power (rs = 0.23 for LF power, P < 0.005), and this especially in middle-aged men (rs = 0.37, P < 0.01). In women (n = 135), no significant correlations between coping style and HRV indices were found. We conclude that in normal individuals, at least in men, our findings suggest a relationship between coping style and cardiac autonomic function.

Relationship of trait, Type A behavior, and physical fitness variables to cardiovascular reactivity and coronary heart disease risk potential

PURPOSE

This research investigated the effects of individual characteristics on cardiovascular reactivity, and in turn on the potential for developing coronary heart disease.

DESIGN

Path analysis was performed using LISREL, a structural equation modeling program providing maximum likelihood estimators and goodness-of-fit measures.

SETTING

Data were collected during a health assessment program, from participants attending a Department of Defense senior service school.

SUBJECTS

Participants were 134 senior-ranking male military and civilian employee volunteers, representing approximately 84% of all students in training.

MEASURES

Five individual characteristics, four measures of cardiovascular reactivity, and one coronary heart disease risk potential variable were investigated. These included Physical Fitness, Type A behavior, Trait Anger and Trait Anxiety, Diastolic and Systolic Blood Pressure measures, and Coronary Heart Disease Risk.

RESULTS

Significant path coefficients (critical ratios > 2) indicated that the mean diastolic blood pressure under a video stress condition was predictive of increased potential of developing coronary heart disease (.51), while hard driving Type A behavior was a cardiovascular reactivity antecedent associated with an increase in coronary heart disease risk directly (.14) and indirectly (.39). Physical fitness, on the other hand, had a positive affect in that increased fitness was related to lower cardiovascular reactivity when participants were stressed (-.58).

CONCLUSIONS

Physical fitness is indirectly beneficial in reducing coronary heart disease risk potential by reducing an individual's diastolic blood pressure response, while scoring high as a Type A Hard Driving personality increases cardiovascular reactivity and coronary heart disease risk. This study is limited to middle-aged males who were generally healthy and displayed concern for their health.

Social determinants of cardiovascular reactivity: effects of incentive to exert influence and evaluative threat

The effects on cardiovascular reactivity of incentive to influence the judgements of the experimenter and the threat of social evaluation were examined in a sample of 60 male and 60 female undergraduates. Participants either were guaranteed $5.00 to prepare and deliver a brief speech or were told that the money was contingent on an evaluation by the experimenter. Participants believed that their speech would be rated for either simple clarity or verbal intelligence. The contingent incentive increased systolic blood pressure reactivity by 6.5 mmHg (32%). Evaluative threat increased systolic reactivity by 7.1 mmHg (36%). These interpersonal processes could increase the risk of cardiovascular disease and are likely to affect the degree of cardiovascular reactivity in laboratory studies.

Ratings of perceived exertion by a group of women: does Type A behavior act a modifier?

It has previously been suggested that individuals displaying the Type A behavior pattern underestimate their perceived exertion during physical exercise. Most research pertaining to these results has been performed with male participants. In the present study, 70 women (mean age 26.8 yr.) varying in scores on the Bortner scale participated in a standardized cycle ergometer test performed individually in a laboratory setting. Analysis showed small but nonsignificant differences in ratings by participants. This held over the whole range from light to heavy exercise intensity. Less than 1% of the explained variance in ratings of perceived exertion (RPE) could be traced back to the scores for behavior of the individuals. Thus, contrary to some prior reports of RPE suppression associated with the Type A behavior pattern, the results present instead a null finding. Possible causes for the equivocal results are the environment (laboratory vs field), the question whether a laboratory test performed individually is perceived as challenging enough to trigger the competitive urge, type of exercise, the individual's sex, the measure used for assessing Type A behavior pattern, and whether gender-based schematic/aschematic processing is involved.

Impact of social environment characteristics on neuroendocrine regulation

OBJECTIVE

This article reviews evidence relating social environment characteristics to patterns of neuroendocrine regulation. To date, although there has been considerable interest in the effects of social ties and support on health and longevity, less attention has been given to the effects of such social environment characteristics on actual physiologic parameters.

METHOD

Animal and human studies from 1960s to the present are reviewed for evidence linking social environment characteristics to patterns of hypothalamic-pituitary-adrenal (HPA) axis, sympathetic nervous system (SNS), and cardiovascular activity.

RESULTS

Community and laboratory-based studies document that characteristics of the social environment influence patterns of neuroendocrine reactivity. These effects seem to be highly sensitive to aspects of the social environment such as relative social status, the relative stability of the social ordering and, importantly, the quality of social relationships. Although supportive social relationships are often associated with attenuated patterns of HPA and SNS activation, the converse also seems to be true as nonsupportive social interactions are frequently associated with enhanced reactivity.

CONCLUSION

Available evidence regarding links between social environment characteristics and neuroendocrine regulation documents a link between the social and biological realms that may have important consequences for health and longevity. The data provide support for the hypothesis that observed associations between social ties and health and longevity result, at least partially, from the positive influence of such social environment characteristics in reducing neuroendocrine reactivity. The evidence regarding nonsupportive or hostile social relationships highlights the importance of taking a broader view of the potential health effects of the social environment, one that encompasses the potential for both positive and negative effects.

Heart rate reactivity and heart period variability throughout the first year after heart transplantation

Heart rate reactivity to mental stress is substantially blunted early after heart transplantation, suggesting that the loss of neural modulation limits the cardiovascular response to mental stress. We tested whether reactivity to mental stress recovers during the first year after heart transplantation. Hemodynamic and respiratory responses to mental arithmetic challenge were studied in 20 heart transplant recipients 3, 6, and 12 months after surgery. A normal comparison group was studied at equivalent intervals. Heart rate reactivity to mental arithmetic was significantly reduced in the cardiac transplant group compared to the normal subjects. This effect persisted up to 1 year after transplantation. Heart period variability in the heart transplant recipients was minimal in all three test sessions. The findings suggest that no functional reinnervation or other compensatory adaptation occurs up to 1 year after heart transplantation.

Temporal stability of heart period variability during a resting baseline and in response to psychological challenge

Central to the psychophysiologic reactivity hypothesis of the etiology of coronary artery disease is the assumption that reactivity is an individual characteristic that is stable over time. Although heart rate (HR) and blood pressure reactivity appear to meet this criterion, temporal stability of cardiac autonomic control as measured by analysis of heart period variability (HPV) has not been assessed. In this study, we tested the stability of HPV, measured in both the time and frequency domain, during a quiet, resting baseline and in response to 5-min mental arithmetic and reaction time tasks, in 20 normal subjects measured in three testing sessions during a 9-month period. Stability, assessed by the intraclass correlation coefficient (ICC), was excellent for resting baseline measures of HR and HPV, with ICCs of 0.68-0.86. However, HR and HPV reactivity to either arithmetic or reaction time tasks generally was less stable, with ICCs of 0.17-0.73, in contrast to results of previous studies demonstrating long-term stability of HR responses to psychological challenge. Stability of aggregated reactivity scores was only slightly improved. Whether for individual tasks or aggregated measures, reactivity of total and low-frequency measures of HPV was moderately stable but stability of high-frequency HPV reactivity was poor.

Aerobic exercise and Type A behaviour

The Type A behaviour pattern is a well-documented, if controversial, risk factor for coronary heart disease. Surprisingly, relatively little work has been reported on ways of modifying this behaviour pattern. Aerobic exercise, with its demonstrated benefits for both cardiovascular reactivity and psychological 'well-being', is a promising treatment. The literature is reviewed and recommendations are made for practical applications and future research.

Type A behavior and adipose tissue linoleic acid: implications for stress management

OBJECTIVE

The purpose of the present study was to investigate the relation between Type A behavior and adipose tissue linoleic acid composition.

METHODS

The sample consisted of 73 male and female Cretan adults, 23-64 years of age. Anthropometric and arterial blood pressure measurements were taken. Adipose tissue samples were collected by aspiration and data concerning general health habits were obtained. Food intake was estimated by a 24-hour dietary recall, while Type A profile was assessed with a Greek translation of the Bortner scale.

RESULTS

Factors associated with Type A profile are adipose tissue linoleic acid (p < 0.0004), annual income (p < 0.001), total serum cholesterol (p < 0.009), and adipose fat myristoleic acid (p < 0.02). Negative correlations were observed between adipose linoleic and myristoleic acids and the dependent variable.

CONCLUSION

It appears that adipose tissue linoleic acid may be one of the etiological factors for Type A behavior in adults.

Type A personalities tend to have low platelet monoamine oxidase activity

This study investigated whether there are relations between type A behaviours and the activity of monoamine oxidase (MAO) in blood platelets. Forty male nonsmokers completed the Jenkins Activity Survey (JAS) and had a blood sample drawn while at work. The JAS was scored in the traditional manner, yielding scores for ambitiousness (factor A), impatience (factor S), competitiveness (factor H) and job involvement (factor J). High scores on JAS scales were associated with low MAO activity in blood platelets; the correlation between platelet MAO activity and job involvement was significant. The findings agree with previous reports in showing relationships between MAO activity and certain personality traits and support the notion that low activity of MAO may contribute to sympathetic hyperreactivity in type A individuals.

Blood pressure responses to acute exercise in type A females

Cardiovascular responses to moderate steady state exercise were studied in type A females. Twenty-one women, ages 18 to 43 years (mean 29.7 +/- 2.0), were divided into type A (n = 11) and type B (n = 10) groups by means of the Jenkins Activity Survey (JAS). Baseline measurement included EMG, BP, and psychometric data. Subjects exercised on a treadmill at 60% VO2 peak for 20 min. Postexercise systolic and diastolic BP (SBP, DBP) reductions were similar in the type A and type B groups [111/72 to 104/66 and 108/70 to 98/62 mmHg, respectively, (F(1, 38) = 4.03, p < 0.05]. However, DBP responses during exercise for type B, but not the type A, were lower [71 +/- 2 to 60 +/- 2 mmHg, preexercise to steady state exercise, (F(1, 38) = 7.14, p < 0.01]. Also, steady state exercise SBP was lower in type B compared to type A [159 +/- 3 vs. 150 +/- 4 mmHg, (F(1, 38) = 3.97, p < 0.05]. These data with psychometric data, suggest that hemodynamic and other physiological responses to exercise in females vary according to behavioral types associated with differing physiology.

Blood pressure responses and incentive appraisals as a function of perceived ability and objective task demand

This experiment examined the role perceptions of ability may play in determining the impact of task demand on cardiovascular responses indicative of active coping. Subjects first performed a scanning task and received feedback indicating that they had either low or high scanning ability. They then were presented with the opportunity to earn one of two incentives by attaining either an objectively low or objectively high standard of performance on a second scanning task. Immediately prior to and during the 1-min performance period, systolic and diastolic blood pressure responses were greater in the difficult standard condition than in the easy standard condition for those who received high-ability feedback but were somewhat diminished in the difficult standard condition as compared with the easy standard condition for those who received low-ability feedback. Whereas high-ability subjects tended to have less pronounced pressor responses than did low-ability subjects when the second task was objectively easy, they had more pronounced pressor responses than low-ability subjects when the second task was objectively difficult. Analysis of goal attractiveness ratings obtained just prior to task performance showed a general correspondence between subjects' anticipatory blood pressure responses and their appraisals of the incentives. Implications for several lines of investigation are discussed.

Effects of demand and decision latitude on cardiovascular reactivity among coronary-prone women and men

According to the Job Strain Model, high demand/low decision latitude jobs may be associated with increased risk of developing coronary heart disease. In further analyses of a laboratory study, the authors hypothesized that Type A behavior and/or hostility moderate the effects of demand, decision latitude, and gender on cardiovascular reactivity, a putative mechanism for the development of coronary disease. With multiple regressions, it was found that scores on the Framingham Type A scale interacted with demand and decision latitude to affect diastolic blood pressure changes, such that Type Bs in the low demand/high decision latitude condition showed the smallest increases in diastolic blood pressure. Among men, hostility accounted significantly and positively for variance in systolic blood pressure changes in addition to that accounted for by high demand. These results suggest that coronary-prone traits may potentiate, or add to, the effects that stressful environments have on health outcomes.

Cardiac response of trained and untrained males to a repeated psychological stressor

The authors examined cardiac response to repeated exposure to a psychological stressor of aerobically conditioned (n = 15) and unconditioned subjects (n = 15). Heart rate and electrocardiographic T-wave amplitude responses of 10 trials of the Stroop Test were monitored during and after performance. Both groups' adaptation patterns were similar, with a plateauing of heart rate response after the third trial. Compared with the unconditioned group, however, the aerobically conditioned subjects recorded lower absolute heart rate responses during and after the stressor for every trial. Relative heart rate responses during the stressor and recovery were similar for both groups. There was also no difference between groups in T-wave response during or after the stressor. These data suggest that absolute heart rate response during and after repeated exposure to a psychological stressor is lower for aerobically trained individuals.

The effect of participation in an exercise training program on cardiovascular reactivity in sedentary middle-aged males

Exaggerated cardiovascular reactivity to mental stressors may be a risk factor for cardiovascular disease. To determine if participation in a moderate intensity aerobic exercise training program reduces cardiovascular reactivity to laboratory stressors, 40 sedentary middle-aged males were randomly assigned: training group (n = 25) and control group (n = 15). Cardiovascular reactivity during and after three mental stressors (passive responding, push-button Stroop and verbal Stroop) and mild exercise (bicycle ergometer) was assessed before and after an 8-week intervention. VO2(peak) was determined using the Balke protocol. Among 19 subjects who completed the training, VO2(peak) increased 13.7%. Also, trained compared to untrained subjects showed significant reductions in baseline and absolute heart rate responses to all stressors. Baseline adjusted heart rates were significantly lower during push-button Stroop recovery and during verbal Stroop. Blood pressure, T-wave amplitude, finger pulse amplitude and pulse transit time responses were unaffected by exercise training. It was concluded that participation in a short-term, moderate intensity aerobic exercise training program may have a cardioprotective effect by significantly reducing absolute and baseline-adjusted heart rate responses to stressors.

Aerobic fitness and opioidergic inhibition of cardiovascular stress reactivity

The role of endogenous opioids in aerobic fitness-induced decrements in cardiovascular stress reactivity was examined by comparing the effects of opioid antagonism with naltrexone on responses to stress in young adults with high versus low levels of aerobic fitness. Two hundred forty subjects were given an activity questionnaire and males with the highest (Fit) and lowest (Nonfit) aerobic activity profiles were recruited for maximal oxygen consumption (VO2max) treadmill testing and psychological stress testing (final sample N = 28). Heart rate and blood pressures were measured during performance on a computer-controlled arithmetic task after pretreatment with either naltrexone (Trexan, DuPont) or a placebo. During placebo challenges, Fit subjects, compared with Nonfit, showed lower heart rate reactivity during stress and lower mean arterial blood pressures immediately before and during recovery from stress. Naltrexone eliminated these reactivity differences by increasing heart rate reactivity and raising mean arterial blood pressure in Fit subjects. These data suggest that aerobic fitness is associated with enhanced opioidergic inhibition of circulatory stress reactivity. Opioidergic modulatory effects on stress reactivity may comprise an important mechanism in fitness-associated risk reduction for cardiovascular disease.

Social interaction, cardiovascular activation and the Type A behavior pattern

The purpose of the study was to explore the relationship between social interaction and cardiovascular activity during a conflict-inducing communication task in Type A and B subjects. One of the subjects, the leader, was instructed to lead the other subject, the follower, through defined routes on a city map merely by help of instructions. The subjects were facing each other on each side of a screen which allowed eye contact but shielded the maps from view. 40 male students (mean age 24 years) exhibiting Type A or Type B behavior according to the Videotaped Structured Interview participated in the study. The results demonstrated large cardiovascular increases during task performance, particularly for leaders, in systolic blood pressure and heart rate. There were no main effects of Type A vs. Type B, but dyads composed of two Type As showed larger increase in diastolic blood pressure during the conflict phase of the task compared to dyads composed of Type Bs.

Power spectral analysis of heart rate variability in Type As during solo and competitive mental arithmetic task

It has been reported that there are differences in autonomic balance between Type As and Type Bs. This study evaluated the sympathovagal interaction in Type A (N = 10) and Type B (N = 10) male students during mental arithmetic task in a solo and a competitive condition by the spectral component analysis of heart rate variability (HRV). The low-frequency (LF) component to high-frequency (HF) component ratio was significantly greater in Type As than in Type Bs, though no significant differences were found in task performance, heart rate change, and blood pressure between the two subject groups in both conditions. The present findings indicate that there was a significant difference in sympathovagal balance between Type As and Type Bs, and that Type As showed dominant sympathetic activity. The results suggest that the power spectral analysis of HRV, which is convenient and non-invasive, has enough sensitivity to discriminate differences in autonomic balance between Type A subjects and Type B subjects, not only during the solo and competitive task period but also during the resting period.

Dimensions of anger-hostility and cardiovascular reactivity in provoked and angered men

This study investigated the relationship between two dimensions of anger-hostility--the expression of anger-hostility and the experience of anger-hostility--and cardiovascular reactivity in provoked and angered men. A serial subtraction task was administered to 41 male undergraduates who were provoked and angered. A measure of the expression of anger-hostility correlated positively and significantly with systolic and diastolic blood pressure (BP) reactivity. There were no significant correlations between a measure of the experience of anger-hostility and cardiovascular reactivity. The two types of anger-hostility were also found to relate differentially to life-style variables that have been identified as risk factors for coronary heart disease (CHD), with only the expression of anger-hostility showing positive relationships with these life-style CHD risk factors. These findings are discussed within the context of a similar differential relationship between the two dimensions of anger-hostility and CAD and CHD. Finally, significant negative relationships were obtained between the experience of anger-hostility and resting BP and heart rate levels. These findings are discussed within the context of other data suggesting that trait anxiety-neuroticism may have protective properties.

Accentuated vagal antagonism of beta-adrenergic effects on ventricular repolarization. Evidence of weaker antagonism in hostile type A men

BACKGROUND

Prior research has suggested a weaker parasympathetic antagonism of sympathetic effects on the heart in type A (coronary-prone) men. To confirm this phenomenon and extend our understanding of it, we investigated the effects of prior muscarinic blockade on the electrocardiogram T wave and other cardiovascular and neuroendocrine responses to isoproterenol in type A and type B (non-coronary-prone) men.

METHODS AND RESULTS

Responses to two 5-minute intravenous isoproterenol infusions (0.01 micrograms/kg/min and 0.02 micrograms/kg/min) were evaluated in six type A and six type B men after pretreatment with either dextrose placebo or atropine (1.2 mg). Atropine significantly potentiated T wave attenuation in the recovery period after isoproterenol infusion (0.30 +/- 0.07 mV) compared with placebo (0.54 +/- 0.09 mV, p less than 0.001). Atropine also potentiated the heart rate increase to isoproterenol (39 +/- 3 beats per minute versus 20 +/- 2 beats per minute after placebo). Atropine enhanced decreases in systolic, diastolic, and mean arterial pressures as well as pulse pressure to isoproterenol. Atropine enhancement of many of these responses was increased among subjects with high scores on various hostility/anger scales. Isoproterenol alone produced greater T wave attenuation in type A than in type B men. However, atropine enhancement of T wave attenuation and blood pressure falls by isoproterenol was present only in type B men.

CONCLUSIONS

These findings indicate that there is accentuated parasympathetic antagonism of T wave attenuation and blood pressure responses induced by beta-adrenergic stimulation. Relative weakness of this antagonism of sympathetic effects on the heart in hostile type A individuals may contribute to their higher coronary disease risk.