Aug 2026· Journal of Nepalgunj Medical College· Vol 24, pp. 83-88· 0 citations· 13 references
TL;DR
Cardiac autonomic tone and its relation with physical fitness level in healthy medical students was evaluated to provide important data regarding autonomic status and physical status which will be useful for both clinical and research purposes.
Abstract
Introduction: Heart rate variability is the indicator that reflects the cardiovascular autonomic nervous system. Regular exercise stimulates structural and functional changes in the cardiovascular and peripheral system that can be measured by heart rate variability. This study was necessary to evaluate cardiac autonomic tone and its relation with physical fitness level in healthy medical students. So that it could provide important data regarding autonomic status and physical status which will be useful for both clinical and research purposes.
Aims: To measure cardiac autonomic tone of medical students using heart rate variability and to look for the relationship between recovery heart rate and cardiac autonomic tone.
Methods: In this cross-sectional study, 57 consenting healthy medical students age 17-30 years, underwent cardiac autonomic tone evaluation through heart rate variability and the cardiac autonomic tone was compared with their physical fitness level which was categorized into four groups that is good, satisfactory, poor and very poor.
Results: No changes in Heart rate variability among four fitness groups were found. But when Spearman’s correlation was done we found out association of heart rate variability measures with recovery heart rate. The recovery heart rate showed significant negative correlation with pNN50, high frequency power and high frequency normalized unit. Whereas, recovery heart rate showed significant positive correlation with low frequency normalized unit and Low frequency/ high Frequency ratio of frequency domain measures of heart rate variability.
Conclusion: This study reflects that parasympathetic activity was higher in increasing fitness level. But in lower fitness level sympathetic activity was higher.
Findings support the value of routine HRV and Ewing's battery assessment in Morvan syndrome for early detection of cardiovascular autonomic involvement and improved clinical monitoring.
Chandregowda Nandan, Ganagarajan Inbaraj, K. Arjun et al.· Revue neurologique (Paris)· 0 citations
Background Cardiac autonomic dysfunction is common in patients with chronic obstructive pulmonary disease (COPD). Although exercise training improves cardiac autonomic function, the effects of changing physical activity on cardiac autonomic function remain unknown. Objective This study aimed to (1) investigate the association between cardiac autonomic function, exercise capacity and physical activity cross-sectionally and (2) relate changes in physical activity, as a result of a 6-month coaching program, to changes in cardiac autonomic function. Methods Autonomic function was assessed objectively using the Polar H10 sensor, measuring (1) resting heart rate during sleep; (2) heart rate variability (SDNN, RMSSD, LF/HF ratio and SD2/SD1 ratio) during sleep and (3) heart rate recovery following the 6-minute walking test (6MWT), and subjectively using the COMPASS 31 questionnaire at baseline and 6-months follow-up. Physical activity (steps per day and movement intensity during walking) was measured using accelerometery. Cross-sectional and longitudinal associations were evaluated. Results In 36 patients with COPD (69% male, mean ± SD age 69 ± 7 years, FEV1 53 ± 13%pred, 28% taking β-blockers), baseline cross-sectional analyses showed weak to moderate associations between heart rate recovery and movement intensity during walking (rs = 0.45) and distance covered during 6MWT (rs = 0.55). Longitudinal analyses over 6-months follow-up showed that changes in daily step count were inversely associated with changes in resting heart rate (rs = −0.48), LF/HF ratio (rs = −0.35) and SD2/SD1 ratio (rs = −0.28) and that changes in movement intensity during walking were inversely associated with changes in SD2/SD1 ratio (rs = −0.51) in patients not taking β-blockers. Conclusion Weak cross-sectional associations were observed between certain parameters of cardiac autonomic function, exercise capacity and physical activity. Increasing the amount of physical activity showed a weak relation with lowering resting heart rate over 6 months in patients not taking influencing medication.
F. Hermans, E. Arents, A. Blondeel et al.· PLoS ONE· 0 citations
Individuals with visual and hearing impairments often experience reduced physical activity and limited participation in daily activities, which may affect autonomic regulation and cardiovascular risk. However, impairment-specific physiological characteristics in young adults remain poorly understood. This exploratory and hypothesis-generating cross-sectional pilot study investigated autonomic modulation during an acute orthostatic stress test in 35 university students divided into three groups: healthy controls, individuals with visual impairments, and individuals with hearing impairments. Indicators of arteriosclerosis, physical function, autonomic nervous system activity assessed by heart rate variability (HRV), physical activity level, and quality of life were evaluated and compared among groups. The primary outcomes of this study were vascular and autonomic responses during the acute orthostatic stress test, specifically the Arterial Velocity Pulse Index (AVI), Arterial Pressure-volume Index (API), and heart rate variability (HRV) indices. Secondary outcomes included baseline body composition, motor performance, daily physical activity levels, and quality of life (QOL) scores. Although no significant group × time interactions were observed for HRV parameters during the acute orthostatic stress test, a significant main effect of group was observed for HF, whereas no significant group effects were observed for the other HRV parameters. Significant group differences were observed for both API and AVI, with post hoc comparisons indicating higher values in the hearing impairment group than in healthy controls. These preliminary findings may suggest potential impairment-specific cardiovascular profiles that warrant further investigation in larger studies. No significant differences were observed in physical function or quality of life among the groups. Overall, the findings should be interpreted cautiously because of the exploratory design and small sample size. These exploratory findings may suggest possible differences in vascular characteristics in young adults with sensory impairments, with exploratory observations regarding autonomic modulation. However, these observations require confirmation in larger adequately powered studies.
It is concluded that hypertensive patients have sympathovagal imbalance with increased sympathetic activity and decreased parasympathetic as compared to normotensive subjects.
Komal Sharma, J. Shukla· Greenfort International Jour...· 0 citations
BACKGROUND
Heart rate variability (HRV) is a non-invasive method of assessing autonomic function. Those with autonomic dysfunction may be at heightened risk of peri-operative complications due to sympatho-parasympathetic imbalance. This review summarises the clinical applications of HRV, approaches to how it is measured, and its role in predicting peri-operative complications.
METHOD
A systematic search of EMBASE and MEDLINE databases was performed, with results screened independently by two reviewers. Primary studies exploring the use of HRV in the context of non-cardiac surgery were eligible. Outcomes of interest were technical parameters involved in assessing autonomic function and peri-operative complications. The data were systematically extracted, charted, and summarised using a narrative synthesis. Due to expected heterogeneity of results, quantitative analysis was not planned.
RESULTS
In total 1513 studies were screened and 63 were eligible for inclusion. Heart rate variability was used to measure autonomic function before surgery (n = 54/63; 85.7%), during surgery (n = 12/63; 19.0%), and after surgery (n = 18/63; 28.6%). HRV indices showed promise for identifying patients at risk of perioperative complications, most commonly comprising mortality, delirium, postoperative pain, myocardial ischaemia, and critical care admission. Measurements of HRV on post-operative day 1 tended to show superior discriminatory value than those performed later during recovery.
CONCLUSION
Multiple clinical applications of HRV exist in the peri-operative period. If demonstrated definitively, HRV in patients undergoing major non-cardiac surgery could identify those at increased risk of perioperative morbidity and mortality.
Reuben Veysey-Smith, Ashmit Bhardwaj, D. Jayne et al.· ANZ journal of surgery· 0 citations
Background: Medical students are frequently exposed to academic, emotional, and psychological stress, which can
adversely affect autonomic nervous system function. Heart Rate Variability (HRV) is a reliable, non-invasive
indicator of autonomic balance and can be used to objectively assess physiological responses to stress. This study
aimed to evaluate the association between heart rate variability and perceived stress among undergraduate medical
students.
Materials and Methods: A cross-sectional observational study was conducted among 150 undergraduate medical
students in the Department of Physiology, Mediciti Institute of Medical Sciences, Ghanpur. Perceived stress was
assessed using the Perceived Stress Scale (PSS-10), and HRV was recorded under standardized resting conditions.
Time-domain parameters (SDNN and RMSSD) and the frequency-domain parameter (LF/HF ratio) were analyzed.
Statistical analysis was performed using SPSS version 25.0, with p < 0.05 considered statistically significant.
Results: The mean age of the participants was 20.8 ± 1.5 years, and 54.0% were females. Moderate stress was
observed in 62.0% of students, while 24.0% experienced high stress. SDNN and RMSSD decreased significantly
with increasing stress levels, whereas the LF/HF ratio increased significantly (p < 0.001). Perceived stress showed a
significant negative correlation with SDNN (r = −0.42) and RMSSD (r = −0.39), and a positive correlation with the
LF/HF ratio (r = 0.36, p = 0.002).
Conclusion: Higher perceived stress was significantly associated with reduced heart rate variability, indicating
impaired autonomic function among undergraduate medical students. Early stress identification and targeted
interventions may improve autonomic health and psychological well-being.
Keywords
Heart Rate Variability; Stress; Perceived Stress Scale; SDNN; RMSSD; LF/HF Ratio; Undergraduate Medical
Students; Autonomic Nervous System.
E. Harni, L. Lakshmi· Journal of MedVerse Research...· 0 citations