Indexes of cardiac autonomic profile detected with short term Holter ECG in health care shift workers: a cross sectional study

The impact of working night shifts on cardiac autonomic nervous regulation during the six-minute walk test in nurses

BACKGROUND

Clinical nurses frequently face the necessity of working night shifts, often with insufficient opportunities for timely sleep recovery, which may negatively impact autonomic nervous system regulation. The aim of this study was to evaluate changes in heart rate variability (HRV) after the six-minute walk test (6MWT) in nurses post-night shift and to explore the impact of night shift work on cardiac autonomic regulation.

METHODS

Thirty-five female nurses, with a mean age of 28.7 years (range 21.0-37.0 years), participated in this study. On the first and second mornings after a night shift, the nurses performed the 6MWT. During the test, electrocardiogram (ECG) signals, blood pressure, and walking distance were recorded simultaneously.

RESULTS

Compared with the second postshift morning, on the first postshift morning, nurses presented higher ratings of perceived exertion (RPE), higher Borg scale scores, and a slower pulse rate before and after the 6MWT but covered a shorter walking distance. Additionally, HRV indicators such as the SDNN, RMSSD, pNN50, TP, VLF, LF, and HF were all higher on the first postshift morning. Regarding the amplitude of cardiac autonomic nervous regulation, variations in the RMSSD and pNN50 were both greater during the 6MWT on the first postshift morning, although there was no significant difference in post-6MWT recovery.

CONCLUSIONS

Night shifts appear to increase the activity of the autonomic nervous system in nurses on the first postshift morning and exert a greater inhibitory effect on parasympathetic activity during the 6MWT. Therefore, it is important to ensure timely recovery sleep and improve autonomic regulation after working night shifts.

KEYWORDS

Heart rate variability; Night shift; Autonomic nervous system; Six-minute walk test; Nurses.

TRIAL REGISTRATION

This study was retrospectively registered in the Clinicaltrials.gov. Registration Date: August 1, 2024.

CLINICALTRIALS

gov ID: NCT06542510.

Influence of shift work on sleep quality and circadian patterns of heart rate variability among nurses

Background

Shift work implementation is essential for providing continuous patient care in hospitals. However, working in shifts on a routine basis may disrupt the circadian pattern and alter the sleep-wakefulness cycle in nurses. Stress due to shift work can influence the adaptability of the cardiovascular system, produce psychophysiological strain and deteriorate work performance in female nurses.

Objective

This study investigated the effect of morning and night shift work on sleep quality and circadian patterns governing heart rate variability (HRV) in female nurses working in a tertiary care hospital.

Methods

Thirty-eight healthy female nurses were recruited. Frequency and time domain parameters of HRV were recorded as markers of cardiac autonomic function. A student t-test was used to investigate differences in HRV between morning and night shift workers. Mann-Whitney non-parametric test was applied for the difference between Pittsburgh Sleep Quality Index (PSQI) scores in the two groups.

Results

Standard deviation of the normal-to-normal interval (SDNN) (msec), total power (ms2) and high-frequency (HF) band power (ms2) were significantly reduced in night shift nurses than in morning shift nurses. The low-frequency (LF)/HF ratio was significantly increased in night shift nurses. The differences in standard deviation of the averages of NN intervals (SDaNN) (msec), root mean square of successive differences between adjacent NN intervals (RMSSD), mean NN, very low-frequency (VLF) band power (ms2) and LF band power (ms2) were not statistically significant. The global PSQI score was significantly higher among night shift workers than in morning shifts.

Conclusion

Inadequate sleep can disrupt the body's ability to regulate heart rhythm and increase the risk of cardiovascular diseases and mortality. The research suggests a propensity for autonomic imbalance in night shift workers when compared to their counterparts on morning shifts.

The effect of extended shift work on autonomic function in occupational settings: A systematic review and meta-analysis

OBJECTIVE

To examine the effect of 24-h shift work on autonomic nervous system function via heart rate variability (HRV) methodologies.

METHODS

Electronic databases (indexed in either PubMed, MEDLINE, CINAHL, SPORTDiscus, or OpenDissertations) were searched from January 1964 to March 2023. A modified Downs and Black checklist was used for assessing methodological quality and the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the quality of evidence. Study design, study population, study sample, shift work description, and assessment of HRV metrics and methods were extracted from each study.

FINDINGS

A total of 58 478 study articles were identified, of which 12 articles met inclusion criteria. Sample sizes varied from eight to 60 participants, with the ratio of low- to high-frequency HRV (LF/HF) as the most common frequency-domain variable reported. Of the nine included studies that observed LF/HF, three (33.3%) demonstrated a significant increase after 24-h shift work. Moreover, of the five studies that reported HF, two (40%) noted a significant decrease after 24-h shift work. When observing risk of bias, two (16.6%) studies were low quality, five (41.7%) were moderate quality, and five (41.7%) were high quality.

INTERPRETATION

There were inconsistent findings demonstrating an effect of 24-h shift work on autonomic function, with a suggested shift away from parasympathetic dominance. Discrepancies in HRV methodologies, such as the duration of recordings and hardware used for measurement, may have contributed to the disparity in findings. In addition, differences in roles and responsibilities across occupations may explain the incongruence in findings across studies.

Relationships Between Sleep Problems and Stress Coping Strategies Adopted by Nurses Including Socio-Occupational Factors

Introduction: The health of nurses has a direct impact on the quality of care and health outcomes for patients. The length and quality of sleep as well as the intensity of perceived stress have an impact on the health of nurses. An appropriate stress coping strategy can reduce the impact of stress and mitigate its negative consequences. Aim: The purpose of this study was to investigate relationships between excessive sleepiness and insomnia in interaction with selected socio-occupational factors and stress coping strategies among nurses. Material and Method: The cross-sectional study was conducted among 448 nurses working in hospitals in Podlasie Province in Poland. Mini-Cope inventory - the polish adaptation of Carver's BriefCope was used for measuring coping with stress. Sleep problems were assessed using the Athens Insomnia Scale and the Epworth Sleepiness Scale. Results: The most frequent used coping strategies were active strategies (active coping, planning). The least-used were avoidant strategies (behavioral disengagement, substance use). Excessive sleepiness affected 38% of surveyed, while insomnia 33%. Excessive sleepiness was most strongly related with behavioural disengagement (R ² = 18.6%), substance use (R ² = 17.5%), humour (R ² = 13.8%) and denial (R ² = 12.0%) while insomnia with substance use (R ² = 17.5%) and self-blame (R ² = 15.9%). Nurses with tertiary education experiencing sleep problems less frequently used the strategy of humour, behavioural disengagement, substance use and religion than with lower education. Nurses working in interventional wards experiencing excessive sleepiness used the strategy of humour, religion and positive reframing less often than those working in other wards while those suffering from insomnia used the strategy of humour more often than those working in other wards. Conclusions: The implementation of avoidant and support-seeking and emotion-oriented stress coping strategies by nurses were associated with the sleep problems. Tertiary education discourages nurses with sleep problems from using avoidant coping strategies and devoting themselves to religion. Education and improvement of the quality of sleep may prevent nurses from resorting to stress coping strategies that have a detrimental effect on their health and well-being.

Relationships Between Heart Rate Variability, Occupational Performance, and Fitness for Tactical Personnel: A Systematic Review

Objectives: Heart Rate Variability has gained substantial interest in both clinical and athletic settings as a measurement tool for quantifying autonomic nervous system activity and psychophysiological stress. However, its uses in tactical work settings, such as military, police, and firefighting environments, remain controversial. Given the physical, mental, and emotional stress public safety personnel face both operationally and in training, heart rate variability measurement may be key in promoting their health, safety and operational effectiveness.

Methods: This study identified, critically appraised, and summarized primary studies investigating relationships between heart rate variability and outcomes of interest to tactical personnel. Key literature databases were searched, and quality assessment checklists were applied to analyze retained literature. The results of the screening and assessment processes, along with key data extracted from each study were summarized and tabulated. Research gaps were also identified to facilitate improvements to how tactical personnel and health or performance providers may best utilize heart rate variability to monitor or promote personnel health and performance, and thereby facilitate public safety.

Results: Twenty studies were included and were all of generally high quality. Cohort size, length of follow-up, measurement objectives, data acquisition, and data analysis all varied considerably across studies, precluding meta-analysis. However, study results correlating heart rate variability and relevant outcomes indicated that overall, heart rate variability is an effective indicator of key fitness and performance elements in the tactical work setting.

Conclusions: Heart rate variability can be an effective health and performance tool in tactical work environments. However, measurement methods must be carefully selected and applied. Further research is required to understand causal relationships. Specifically, larger cohort inclusion and the isolation and study of specific variables unique to public safety work and training may improve the effectiveness of heart rate variability measurement to provide meaningful information to end users and providers.