Stress and strain of blue and white collar workers during work and leisure time: results of psychophysiological and behavioral monitoring.

This study of 29 blue and 57 white collar workers (mean age 50 and 51 yr) investigated behavior and the level of subjective stress and objective strain during work and leisure time. Physiological and psychological parameters as well as behavioral activities were assessed simultaneously using a special ambulatory monitoring device capable of storing 23 h records. Total strain was operationalized by heart rate (HR), physical strain by physical activity, emotional strain by non-metabolic HR, and mental strain by HR variability. Analysis of the physiological parameters for the working hours from 8 to 16 h revealed differences between the hours for physical activity, HR, and non-metabolic HR but not for HR variability. Between 12 and 13 h, physical activity was somewhat lower and non-metabolic HR higher, presumedly caused by the lunch break. Physical activity and HR were higher for blue than white collar workers due to the different tasks of the workers. Self-reports of excitement and enjoyment during the working hours showed no main effects in the MANOVA. Comparison between total working time and leisure time revealed lower physical activity and HR but higher non-metabolic HR for leisure time. In the self-reports, however, leisure time was rated less exciting and more pleasant than working time. There was no indication of higher emotional strain for one or the other group, but mental strain at work was somewhat higher for the blue collar workers. In a questionnaire, white collar workers reported having significantly more stress at work and outside work than blue collar workers. Analysis of the behavior during leisure time (physical activity, activity, social contacts) showed only minor differences between the groups.

Differences between patients with asymptomatic and symptomatic myocardial infarction: the relevance of psychological factors.

Several hypotheses describe the phenomenon asymptomatic myocardial infarction (MI) blockade of afferent cardiac nerves, pain inhibition by endogenous opioids, and insufficient severity of myocardial ischaemia. Psychological factors, however, are rarely considered. The present study involved 35 asymptomatic (AMI) and 35 symptomatic patients (SMI) selected from a sample of 199 patients with myocardial infarction. During observation in a rehabilitation clinic, the following were assessed: biochemical variables; ECG at rest, at exercise, and during Holter monitoring; and a special 23 h monitoring of physical activity, ECG changes, and subjective feelings. Psychological assessments with questionnaires were also performed and comprised: personality evaluation; physical complaints; possible predisposing features for the development of MI; expectations regarding the benefit of rehabilitation; circumstances at the time of infarction; and socioeconomic and historical data. The hypothesis that physiological factors might explain the differences between AMI and SMI is not substantiated by our results. However, the hypothesis of the role of psychological factors is supported. As opposed to AMI patients, SMI patients are characterized by frequent complaints of poor health, neuroticism, and introversion. At the time of infarction, SMI patients had more frequent premonitory symptoms of longer duration. Moreover, SMI patients had more frequent previous hospital or nursing home admissions. At the end of the rehabilitation treatment, only 43% of the SMI patients were judged by their physician as fit for work as against 71% of the AMI patients.

Diurnal variations of ECG parameters during 23-hour monitoring in cardiac patients with ventricular arrhythmias or ischemic episodes.

ECG and physical activity (recorded with motion detectors) were continuously monitored during 23 hours in 31 male cardiac patients (81% with myocardial infarction). According to the occurrence of ventricular arrhythmias (VA) or ischemic episodes (IE), each patient was grouped in one of three diagnostic categories: neither VA nor IE, VA with or without IE, and IE only. Analysis of the ECG parameters was done beat-by-beat and averaged on a 1-min basis. Results were derived from the 2-hour means between 2 p.m. and 12 p.m. MANOVA revealed significant group differences for heart rate variability (greater for the group with VA), R-wave amplitude (higher for the group with IE), and P-wave amplitude (higher for the group with VA). Significant time effects were observed for all variables except QRS- and P-wave durations. As may be expected, physical activity and heart rate were lower at night. Heart rate variability, PQ-interval, PR-segment, QT-interval, ST-segment, and T-wave duration increased during the night. R-wave amplitude also increased but the relative P- and T-wave amplitudes decreased. The corrected QT-interval, QTc, was shorter at night and the ST-segment, J + 60-point, S-wave, and J-point amplitudes were less negative. Group X Time interactions were observed for T-wave amplitude. For this amplitude, the decrease during the night was prominent only for the VA group. The results of this study suggest that the three diagnostic groups can be differentiated by diverse ECG parameters.

Detection of emotionally induced ECG changes and their behavioural correlates: a new method for ambulatory monitoring.

Heart rate is a well-established indicator of emotional arousal and can serve to detect emotional events. One difficulty, however, is in separating emotional heart rate increases from those increases due to physical activity. On-line analysis of both heart rate and physical activity (recorded with motion detectors) with a portable minicomputer may be able to solve this problem. We have developed a special algorithm that compares the values for heart rate and activity of a particular minute with the values of the previous minutes. If heart rate of a specific minute exceeds the rate of the previous minutes without an accompanying increase of activity, an emotional event may possibly be assumed. In such a case, the patient is requested by a beep signal to answer relevant questions about what he is doing, how he feels, etc. Moreover the patient is allowed to activate the system for himself for special events, e.g. chest pain. Methodological results of a first feasibility study with 32 cardiac patients are presented.