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To test the level of agreement of heart rate and reactivity to stressor tasks as measured via noninvasive ECG and pulse, 38 healthy subjects underwent four stressor tasks: mental arithmetic, reaction time, cold pressor, and bicycling. Data on resting and stressor heart rate were collected via ECG and photoplethysmography, and heart rate reactivity was calculated via five methods noted in the wider literature. Results indicated that, although resting heart rate values did not differ significantly across the two instruments, there were some significant differences in heart rate during certain periods of mental and physical stress reactivity. Calculation of heart rate reactivity revealed that there were few significant differences between data from the two measures but that the tasks themselves produced markedly different patterns of reactivity, questioning assumptions underlying comparison of reactivity data under different stress tasks. Implications for the assessment of reactivity are discussed.

The relationship between heart rate reactivity and atherogenesis is examined. Data from empirical studies are presented which support theoretical suggestions that it is the heart rate itself rather than the increase in heart rate following the onset of a stressor which is causally related to the development of arterial atherosclerosis. Several directions for research which will clarify this issue are discussed, with recent developments in the detection of atherosclerosis suggested as forming the basis of more reliable investigation of the effects of cardiac output variables upon arterial atherogenesis.

The maintenance over time (4 months) and generalizability (to a work setting) of laboratory-based heart rate reactivity control training was investigated. Forty-three subjects received 5 weeks of biofeedback, imagery, and breathing training and 41 subjects acted as controls. Although there were no significant differences between the reactivities of the control and those of the treatment subjects at any of three pretraining tests, significant differences were noted immediately following training, 7 weeks, and 4 months later, showing maintenance effects. Data collected during work activities on the frequency of reactivity of a magnitude similar to that in the laboratory also showed that treatment subjects had significantly fewer incidents of reactivity than control subjects after training. Followup interviews with treatment subjects indicated that lifestyles were also enhanced in a variety of areas, suggesting that the training had wider benefits. Issues for further research are discussed.

Heart rate and reactivity from pulse and ECG were compared over rest and mental arithmetic periods of 2-min duration each for 32 males and 50 females. Data from the two sources of heart rate were not significantly different during the rest period but did differ significantly during periods of heart rate acceleration and deceleration. Sex effects were also noted, with females having consistently higher heart rates from both sources of measurement. Calculation of heart rate reactivity via five procedures based upon the wider literature revealed significant differences between data from different sources of heart rate. Implications for assessment of heart rate reactivity to laboratory stressors are discussed, with suggestions for future research.

Heart rate reactivity to a standardized laboratory stressor (mental arithmetic under timed and competitive conditions) was measured in 37 men and women, drawn from white- and blue-collar occupations. In addition, heart rate reactivity data during 4 hr of work were gathered on each of these subjects and analyzed to determine (1) the presence during work time of reactivity equal to or greater than that to the mental arithmetic stressor; (2) the incidence of reactivity of 5, 10, 15, and 20 bpm during work time, and (3) the predictability of frequency of work time reactivity by mental arithmetic reactivity. Data suggested that, although there were several incidences of heart rate reactivity responses during work which were similar to those noted in the laboratory, these work heart rate responses were not able to be significantly predicted by laboratory heart rate responses.

The effectiveness of cardiac education and visual biofeedback of heart rate as a training procedure to teach people to control their heart rate to a psychological stressor was investigated with 36 students, half of whom acted as control subjects. Training took 5 weeks and consisted of 30-min per week of awareness training, plus exercises to increase and decrease heart rate under rest and stressful conditions, with monetary rewards for success. Effects were tested by pre-post test comparisons between the control and the experimental groups, and results indicated that the group which received training significantly lowered its heart rate reactivity even though not specifically instructed to do so. However, when instructed to control heart rate reactivity for a monetary reward, the control group also succeeded at this task, raising several issues regarding the efficacy of reactivity training.