Regular physical exercise, heart rate variability and turbulence in a 6-year randomized controlled trial in middle-aged men: The DNASCO study

Aerobic Exercise Improves Heart Rate Variability After an Implantable Cardioverter Defibrillator (ICD)

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov: NCT00522340.

Lumbar Paravertebral Muscle Pain Management Using Kinesitherapy and Electrotherapeutic Modalities

BACKGROUND

Low back pain is considered a public health problem internationally. Low back pain is a cause of disability that occurs in adolescents and causes negative effects in adults as well. The work environment and physical and psychosocial factors can influence the occurrence and evolution of low back pain.

METHODS

The purpose of this paper is to highlight the physiological and functional changes in young adults with painful conditions of the lumbar spine, after using exercise therapy. The study was of the longitudinal type and was carried out over a period 6 months in an outpatient setting. The rehabilitation treatment included electrotherapeutic modalities and kinesitherapy.

RESULTS

The results obtained when evaluating each parameter, for all moments, show statistically significant values in both groups. The results obtained regarding the relationship between the therapeutic modalities specific to rehabilitation medicine and low back pain are consistent with those reported in studies.

CONCLUSIONS

Depending on the clinical-functional status of each patient, kinesitherapy can accelerate the heart rate and increase the blood pressure and oxygen saturation of the arterial blood, values that can later return to their initial levels, especially through training.

Exploration of cardiac rehabilitation nursing for elderly patients with myocardial infarction based on individualized cardiac rehabilitation

BACKGROUND

Myocardial infarction is a high-risk condition prevalent among the elderly population, often leading to adverse clinical manifestations such as reduced cardiopulmonary function, anxiety, and depression post-surgery. Consequently, cardiac rehabilitation holds immense importance in mitigating these complications.

AIM

To evaluate the effect of individualized cardiac rehabilitation on blood pressure variability (BPV) and baroreflex sensitivity (BRS) in elderly patients with myocardial infarction.

METHODS

A cohort of 74 elderly patients diagnosed with myocardial infarction and admitted to our hospital between January 2021 and January 2022 were subjected to random selection. Subsequently, all patients were divided into two groups, namely the research group (n = 37) and the control group (n = 37), utilizing the number table method. The control group received conventional drug treatment and nursing guidance intervention, while the study group underwent individualized cardiac rehabilitation in addition to the interventions received by the control group. All patients were continuously intervened for 12 wk, and the BPV of these two groups in the 1st wk (T0), the 4th wk (T1) and the 12th wk (T2) were compared, BRS, changes in cardiopulmonary function measures, and adverse cardiovascular events.

RESULTS

Of 24 h diastolic BPV, 24 h systolic BPV, carbon dioxide ventilation equivalent slope of the research group were lower than those of the control group at T1 and T2, BRS, peak heart rate and systolic blood pressure product, 1 min heart rate recovery were higher than those of the control group, and the incidence of adverse events in the research group was lower than that of the control group, the difference was statistically significant (P < 0.05).

CONCLUSION

In this study, we found that after individualized cardiac rehabilitation in elderly patients with myocardial infarction, BPV and BRS can be effectively improved, cardiac function is significantly enhanced, and a better prognosis is obtained.

Effects of Training on Running Cost and Aerobic Capacity in Individuals with Obesity

This study investigated running cost (CRun), peak oxygen consumption (V̇ O2peak), and ventilatory threshold (VT1) responses to exercise programs for individuals with obesity. Ninety-four individuals (38.2±7.7 years; 33.4±2.9 kg/m²) were assigned into strength (n=24), endurance (n=26), combined (n=22), and physical activity (control, n=22) groups for 22 weeks, plus diet recommendation. The V̇ O2peak, VT1, and CRun were assessed through a maximal incremental step test. The change of V̇ O2peak in combined (9.9%) differed from the other groups, with lower values in women than men (0.7% vs. 6.2%). The VT1 change in combined (16.4%) differed from the strength (4.9%) and physical activity (1.2%) groups, with the change in endurance (12.7%) also being higher than the physical activity group. Only men in the combined group increased absolute V̇ O2peak, while both sexes increased VT1 in the endurance and combined groups. No effects for groups and sex were significant for CRun in moderate (VT1) running zones, despite CRun changes in VT1 zones correlated with the alterations of V̇ O2peak and VT1 (r²=0.29-0.59). Therefore, moderate aerobic exercise stimulus is suitable for VT1 improvement in individuals with obesity, with the increase in CRun associated to the chances of increasing V̇ O2peak in men and when combining strength with aerobic exercises.

Normative values of resting heart rate variability in young male contact sport athletes: Reference values for the assessment and treatment of concussion

Objective

The objective of this study was to identify the main determinants of heart rate variability (HRV) in male athletes aged 14 to 21 years who practice competitive contact sports and to integrate these determinants with the aim of defining normative values of short-term HRV in the time and frequency domains.

Methods

Participants (n = 369) were aged 14 to 21 years and included 221 football players and 148 ice hockey players. HRV was measured for 5 min at rest, and standard HRV parameters in the time and frequency domains were calculated. Heart rate (HR), age, body mass index (BMI), number of sports weekly practices (WSP) and concussion history (mTBI) were considered determinants potentially able to influence HRV.

Results

Multiple regression analysis revealed that HR was the primary determinant of standard HRV parameters. The models accounted for 13% to 55% of the total variance of HRV and the contribution of HR to this model was the strongest (β ranged from -0.34 to -0.75). HR was the only determinant that significantly contributes to all HRV parameters. To counteract this dependence, we calculated HRV corrected by the mean RR interval (RRm). Such corrections do not remove any physiological differences in HRV; they simply remove the mathematical bias. HRV parameters were therefore normalized, and their normative limits were developed relative to the mean heart rate. After correction, the correlation coefficients between HR and all corrected HRV parameters were not statistically significant and ranged from -0.001 to 0.045 (p > 0.40 for all). The automatically corrected HRV calculator, which recalculates standard HRV parameters and converts them into corrected parameters in addition to determining whether a given value is within normal limits, facilitates clinical interpretation.

Conclusion

This study provides for the first time corrected normative values of short-term and resting state HRV parameters in competitive contact sport athletes aged 14 to 21 years. These values were developed independently of the major determinants of HRV. The baseline values for HRV parameters given here could be used in clinical practice when assessing and monitoring cerebral concussions. They may assist in decision making for a safe return to play.

Compression therapy, autonomic nervous system, and heart rate variability: A narrative review and our preliminary personal experience

Aims

To highlight the relationship among compression therapy (CT), the autonomic nervous system (ANS) (parasympathetic and sympathetic system), and the heart rate variability (HRV) analysis.

Background

Beyond the typical analgesic and anti-inflammatory effects of CT in patients affected by venous and/or lymphatic diseases, some literature about CT influence on wellbeing has been published as well. More specifically, CT influence on the ANS has been elucidated mostly through HRV application, providing useful quali-quantitative data for scientific and clinical purposes.

Material and Methods

A literature search was performed through several web-based search engines to investigate the available evidence concerning the possible influence of CT on the ANS and on psychoneuroendocrineimmunology. Moreover, we examined literature data regarding HRV use in the assessment of CT. Lastly, a preliminary cross-over study was performed on 10 patients affected by phlebolymphedema of the lower limbs, undergoing CT with 18–21 mmHg stockings for 10 h and investigated by means of HRV.

Results

A CT-based increase of the anti-inflammatory activity of the parasympathetic (vagal) system has been elucidated in most scientific literature. Similarly, CT application has generally resulted in an improvement of HRV, which indicates a beneficial influence on the ANS. In our preliminary experience with compression stockings and HRV, two parasympathetic-based parameters improved by 22.8% and 68.0% after 10 h, whereas they decreased in the same subjects without stockings by 2.7% and 8.2%, during normal breathing. The remaining HRV parameters did not show relevant variations, especially during diaphragmatic breathing.

Conclusions

From literature data and based on our very preliminary experience, it is possible to deduce that CT exerts different effects on the psychobiological parameters of the individual, overall improving HRV and parasympathetic activity. Incorporating both HRV/ANS assessment in phlebolymphology and the beneficial neural action of CT in health care may represent viable options in the future biomedical science.

A Cognitive Behavioral Model Proposing That Clinical Burnout May Maintain Itself

Burnout is common in many countries and is associated with several other problems such as depression, anxiety, insomnia, and memory deficits, and prospectively it predicts long-term sick-leave, cardiovascular disease, and death. Clinical burnout or its residual symptoms often last several years and a common assumption is that recovery takes a long time by nature, despite full time sick-leave and the absence of work stress. The literature suggests models that hypothetically explain the development, but not maintenance, of the syndrome. Based on cognitive and behavioral principles, stress research, and stress theories, this paper describes a theoretical model explaining how clinical burnout can develop and be maintained. While the development of clinical burnout is mainly explained by prolonged stress reactions and disturbed recovery processes due to work related stressors, maintenance of the syndrome is particularly explained by prolonged stress reactions and disturbed recovery processes due to the new context of experiencing burnout and being on sick-leave. Worry about acquired memory deficits, passivity and excessive sleep, shame, fear of stress reactions, and the perception of not being safe are examples of responses that can contribute to the maintenance. The model has important implications for research and how to intervene in clinical burnout. For example, it can offer support to professional care providers and patients in terms of focusing on, identifying, and changing current contextual factors and behaviors that maintain the individual’s clinical burnout symptoms and by that facilitate burnout recovery. Regarding research, the model provides a highly important reason for researchers to study contextual factors and behaviors that contribute to the maintenance of clinical burnout, which has been neglected in research.

HRT assessment reviewed: a systematic review of heart rate turbulence methodology

Heart rate turbulence (HRT) is a biphasic reaction to a ventricular premature contraction (VPC) mainly mediated by the baroreflex. It can be used for risk stratification in different disease patterns. Despite existing standards there is a lot of variation in terms of measuring and calculating HRT, which complicates research and application.

OBJECTIVE

This systematic review outlines and evaluates the methodological spectrum of HRT research, especially filtering criteria, parameter calculation and thresholds.

APPROACH

The analysis includes all research papers written in English that have been published before 12.10.2018, are listed on PubMed and involve calculation of HRT parameter values.

MAIN RESULTS

HRT assessment is still being performed in various ways and important specifications of the methodology are not given in many articles. Nevertheless, some suggestions regarding HRT methodology can be made: a normalised turbulence slope should be used to uncouple the parameter from heart rate and frequency of extrasystoles. Filtering criteria as formerly reviewed in the guidelines should be met and mentioned. The minimal number of VPC snippets (VPCSs) as well as new cut-off values for different risks need to be further evaluated. Most importantly, the exact and complete methodology must be described to ensure reproducibility and comparability.

SIGNIFICANCE

Methodical variation hinders comparability of research and medical application. Our continuing questions help to further standardise the measurement and calculation of HRT and increase its value for medical risk stratification.

Effects of smoking status, history and intensity on heart rate variability in the general population: The CHRIS study

Background

Heart rate variability (HRV) reflects the autonomous nervous system modulation on heart rate and is associated with several pathologies, including cardiac mortality. While mechanistic studies show that smoking is associated with lower HRV, population-based studies present conflicting results.

Methods

We assessed the mutual effects of active smoking status, cumulative smoking history, and current smoking intensity, on HRV among 4751 adults from the Cooperative Health Research In South Tyrol (CHRIS) study. The HRV metrics standard deviation of normal-to-normal (NN) inter-beat intervals (SDNN), square root of the mean squared differences of consecutive NN intervals (RMSSD), total power (TP), low (LF) and high frequency (HF) power, and their ratio (LF/HF), were derived from 20-minute electrocardiograms. Smoking status, pack-years (PY), and tobacco grams/day from standardized questionnaires were the main exposures. We fitted linear mixed models to account for relatedness, non-linearity, and moderating effects, and including fractional polynomials.

Results

Past smokers had higher HRV levels than never smokers, independently of PY. The association of HRV with current smoking became apparent when accounting for the interaction between smoking status and PY. In current smokers, but not in past smokers, we observed HRV reductions between 2.0% (SDNN) and 4.9% (TP) every 5 PY increase. Furthermore, current smokers were characterized by dose-response reductions of 9.8% (SDNN), 8.9% (RMSSD), 20.1% (TP), 17.7% (LF), and 19.1% (HF), respectively, every 10 grams/day of smoked tobacco, independently of common cardiometabolic conditions and HRV-modifying drugs. The LF/HF ratio was not associated with smoking status, history, or intensity.

Conclusions

Smoking cessation was associated with higher HRV levels. In current smokers, heavier smoking intensity appears gradually detrimental on HRV, corroborating previous evidence. By affecting both the sympathetic and parasympathetic nervous system indexes, but not the LF/HF balance, smoking intensity seems to exert a systemic dysautonomic effect.

Severe abnormal Heart Rate Turbulence Onset is associated with deterioration of liver cirrhosis

Background

In patients with liver cirrhosis, cardiac dysfunction is frequent and is associated with increased morbidity and mortality. Cardiac dysfunction in cirrhosis seems to be linked to autonomic dysfunction. This study investigates the role of autonomic dysfunction assessed by Heart Rate Turbulence (HRT) analyses in patients with liver cirrhosis.

Methods and patients

Inclusion criteria was (1) diagnosis of cirrhosis by clinical, imaging or biopsy and (2) evaluation by standard 12-lead-ECG and 24h holter monitoring and (3) at least 3 premature ventricular contractions. The exclusion criterion was presence of cardiac diseases, independent of liver cirrhosis. Biochemical parameters were analysed using standard methods. HRT was assessed using Turbulence onset (TO) and slope (TS). The endpoint was deterioration of liver cirrhosis defined as increased MELD and readmission for complications of liver cirrhosis.

Results

Out of 122 cirrhotic patients, 82 patients (63% male) with median Child score of 6 (range 5–12) and median MELD score of 10 (range 6–32) were included. Increasing Child score, INR and decreasing albumin were correlated with TO. In addition, decompensated patients with ascites showed more abnormal TO and TS. During the observation period, patients with more abnormal TO showed significantly higher rate of rising MELD Score at 6 months (p = 0.03). Nevertheless, at least in our collective HRT-parameters were not independent predictors of deterioration of cirrhosis.

Conclusion

Parameters of HRT are closely associated with deterioration of cirrhosis and might be helpful in its prediction.

What is the most effective exercise protocol to improve cardiovascular fitness in overweight and obese subjects?

BACKGROUND

Increased peak oxygen consumption (VO_2peak) can reduce cardiovascular risks associated with obesity. Our aim was to analyze the effect of a weight loss program on cardiovascular fitness in overweight (W) and obese (O) subjects.

METHODS

One hundred and sixty-seven subjects (77 males and 90 females), aged 18-50 years, performed a modified Bruce protocol before (pre) and after (post) a weight loss program of 24 weeks. This program combined physical training (strength, S; endurance, E; combined strength + endurance, SE; or physical activity recommendation, PA) 3 times per week, with a 25%-30% caloric restriction diet.

RESULTS

VO_2peak improved in overweight and obese males (pre and post values in L/min, respectively; W = 3.2 ± 0.6 vs. 3.7 ± 0.5, p < 0.001; O = 3.6 ± 0.6 vs. 3.8 ± 0.6, p = 0.013) as well as in overweight females (2.0 ± 0.3 vs. 2.3 ± 0.4, p < 0.001). VO_2peak in the first ventilatory threshold (VT₁) increased for all 4 interventions in males (p < 0.05), except for S in the obese group (1.6 ± 0.2 vs. 1.7 ± 0.3, p = 0.141). In females, it increased in E (0.9 ± 0.2 vs. 1.4 ± 0.3, p < 0.001), SE (0.9 ± 0.2 vs. 1.2 ± 0.4, p = 0.003), and PA (0.9 ± 0.1 vs. 1.2 ± 0.2, p = 0.006) in overweight groups. Time-to-exhaustion improved in all subjects except for females in PA group (15.7 ± 0.3 min vs. 15.9 ± 0.3 min, p = 0.495).

CONCLUSION

Our results suggest that all methods, including the recommendation of physical activity, can improve cardiovascular fitness in overweight subjects and obese males.

Post-exercise hypotension and heart rate variability response after water- and land-ergometry exercise in hypertensive patients

BACKGROUND

systemic arterial hypertension is the most prevalent cardiovascular disease; physical activity for hypertensive patients is related to several beneficial cardiovascular adaptations. This paper evaluated the effect of water- and land-ergometry exercise sessions on post-exercise hypotension (PEH) of healthy normotensive subjects versus treated or untreated hypertensive patients.

METHODS

Forty-five older women composed three experimental groups: normotensive (N, n = 10), treated hypertensive (TH, n = 15) and untreated hypertensive (UH, n = 20). The physical exercise acute session protocol was performed at 75% of maximum oxygen consumption (VO2max) for 45 minutes; systolic (SBP), diastolic (DBP) and mean (MBP) blood pressure were evaluated at rest, peak and at 15, 30, 45, 60, 75 and 90 minutes after exercise cessation. Additionally, the heart rate variability (HRV) was analyzed by R-R intervals in the frequency domain for the assessment of cardiac autonomic function.

RESULTS

In both exercise modalities, equivalent increases in SBP were observed from rest to peak exercise for all groups, and during recovery, significant PEH was noted. At 90 minutes after the exercise session, the prevalence of hypotension was significantly higher in water- than in the land-based protocol. Moreover, more pronounced reductions in SBP and DBP were observed in the UH patients compared to TH and N subjects. Finally, exercise in the water was more effective in restoring HRV during recovery, with greater effects in the untreated hypertensive group.

CONCLUSION

Our data demonstrated that water-ergometry exercise was able to induce expressive PEH and improve cardiac autonomic modulation in older normotensive, hypertensive treated or hypertensive untreated subjects when compared to conventional land-ergometry.

Effects of moderate exercise on relieving mental load of elementary school teachers

Long-term endurance exercise could increase activity of parasympathetic nervous and decrease activity of sympathetic nervous at rest. However, previous studies all focused on the effect of endurance training on heart rate variability (HRV) for athletes or sedentary subjects. In Taiwan, elementary school teachers teaching and processing the children's and administrative problems always stand and walk. They will sit down only when they review and correct the students' home work. Thus, the goal of this study was to elucidate the beneficial effect of moderate intensity exercise on relieving mental load of elementary school teachers. There were 20 participants in the exercise group and another 20 participants in the nonexercise group. The exercising teachers performed 12 weeks of moderate intensity exercise training for an average of 30 minutes per day, 3 times per week. HRV was measured before and after the 4th, 6th, and 12th weeks. The time and frequency domain parameters of HRV all had significant increases between the beginning and after 12 weeks of training. However, the time and frequency domain parameters of HRV in the nonexercise group had significant decreases between the beginning and after 12 weeks of training. The long-term moderate exercises can relieve mental load of elementary school teachers. Moreover, age was the considerable factor affecting HRV in this study.

Reproducibility of heart rate turbulence indexes in heart failure patients

Cardiovascular oscillations following spontaneous ventricular premature complexes (VPC) are characterized by a short-term heart rate fluctuation known as heart rate turbulence (HRT) described by the so-called turbulence onset (TO) and slope (TS). Despite a recent written consensus on the standard of HRT measurement, reproducibility data are lacking. Aim of the paper was a reproducibility study of HRT indexes in heart failure patients (HF). Eleven HF patients underwent two 24h ECG Holter recordings, spaced 7 ± 5 days. A paired t test was used to assess the clinical stability of patients during the study period and the number of PVC in Holter recordings' couples. Both TO and TS indexes were calculated for each isolated VPC, and due to their skewed distribution, reproducibility of median and mean TO and TS was studied by Bland-Altman technique. Results showed that median HRT indexes might be preferred to commonly suggested mean values and that, although TO showed lower bias value than TS, TS can be considered much more reproducible than TO, comparing limits of agreements with normal values. This preliminary results suggest the use of medians instead of mean HRT indexes values and a reliability of the turbulence slope greater than the turbulence onset index.

Autonomic contribution to endothelin-1 increase during laboratory anger-recall stress in patients with coronary artery disease

In coronary artery disease (CAD), endothelin-1 (ET-1) is released by activated macrophages and thereby contributes to coronary plaque rupture and triggered cardiac events. The multifactorial regulation of ET-1 includes stimulated release by cytokines and autonomic factors. Laboratory stress provokes alteration in autonomic tone and prolonged ET-1 mediated endothelial dysfunction. The objective of the study is to determine the autonomic contribution to an increase in ET-1 in response to laboratory stress in patients with CAD. Patients (n = 88) with chronic stable CAD instrumented with hemodynamic monitor, digital electrocardiogram (ECG) monitor and indwelling catheter for blood sampling completed a laboratory protocol that included initial rest (30 min), baseline (BL: 10 min), and anger recall stress (AR: 8 min). Change from BL to AR was determined for (a) parasympathetic activity (by spectral analysis of ECG); (b) sympathetic activity (by circulating catecholamines); and (c) ET-1. AR provoked increases from BL in catecholamines, and a decrease in parasympathetic activity. Multivariate analysis with change in parasympathetic activity and catecholamines, while controlling for age and use of β-blockers, revealed a significant odds ratio (OR = 3.27, 95% CI 1.03, 10.41 P = 0.04) for an increase in ET-1 associated with parasympathetic withdrawal; no other variables were significant. The predominant influence of parasympathetic activity on anger/stress-provoked increase in ET-1 is consistent with the cholinergic antiinflammatory pathway. Future examination of autonomic influences on atherosclerotic leukocytes, endothelial cell function and the dynamics of ET-1 are warranted.

Electrocardiographic changes with the onset of diabetes and the impact of aerobic exercise training in the Zucker Diabetic Fatty (ZDF) rat

Background

Early markers of diabetic autonomic neuropathy (DAN) in an electrocardiogram (ECG) include elevated R wave amplitudes, widening of QT_c intervals and decreased heart rate variability (HRV). The severity of DAN has a direct relationship with mortality risk. Aerobic exercise training is a common recommendation for the delay and possible reversal of cardiac dysfunction. Limited research exists on ECG measures for the evaluation of aerobic exercise training in Zucker Diabetic Fatty (ZDF) rat, a model of type 2 diabetes. The objective of this study was to assess whether aerobic exercise training may attenuate diabetes induced ECG changes.

Methods

Male ZDF (obese fa/fa) and control Zucker (lean fa/+) rats were assigned to 4 groups: sedentary control (SC), sedentary diabetic (SD), exercised control (EC) and exercised diabetic (ED). The exercised groups began 7 weeks of treadmill training after the development of diabetes in the ED group. Baseline (prior to the training) and termination measurements included body weight, heart weight, blood glucose and glycated hemoglobin levels and ECG parameters. One way repeated measures ANOVA (group) analyzed within and between subject differences and interactions. Pearson coefficients and descriptive statistics described variable relationships and animal characteristics.

Results

Diabetes caused crucial changes in R wave amplitudes (p < 0.001), heart rate variability (p < 0.01), QT intervals (p < 0.001) and QT_c intervals (p < 0.001). R wave amplitude augmentation in SD rats from baseline to termination was ameliorated by exercise, resulting in R wave amplitude changes in ED animals similar to control rats. Aerobic exercise training neither attenuated QT or QT_c interval prolongation nor restored decreases in HRV in diabetic rats.

Conclusion

This study revealed alterations in R wave amplitudes, HRV, QT and QT_c intervals in ZDF rats. Of these changes, aerobic exercise training was able to correct R wave amplitude changes. In addition, exercise has beneficial effect in this diabetic rat model in regards to ECG correlates of left ventricular mass.

Associations between physical activity and health parameters in adolescent pupils in Egypt

Physical activity (PA) could be protective against hypertension, atherosclerosis, coronary heart disease and cardiovascular disease. This quantitative study assessed the association between a PA intervention and three anthropometric parameters (weight, body mass index, body fat) and four physiological parameters (cholesterol level, systolic blood pressure, diastolic blood pressure, heart rate) among secondary school pupils (N = 160) in Egypt through the school term. The pupils were randomised to an intervention group (80 pupils) and controls (80 pupils). Measurements were obtained for all pupils twice: at baseline; and then again after three months. The PA intervention programme comprised an ‘afterschool’ one hour of moderate exercise three times a week for three months. Both the controls and the intervention pupils attended the ‘normal’ exercise schedule provided by the school; in addition, the intervention group attended afterschool PA programme from about 2–3 o’clock in the afternoon. At baseline, employing pupil’s BMI, 27.5% and 28.8% of the intervention and control pupils respectively were classified as overweight. After three months, the percentage of overweight decreased to 12.5% in the intervention pupils, while it increased to 37.3% in the controls. At the end of the three months period, there were significant improvements across most anthropometric and physiological parameters of the intervention pupils when compared with the control children. The correlation coefficient of the improvements for the boys and the girls was 0.97, indicating clearly that the intervention was having nearly the same beneficial effect for boys and girls. A moderate PA programme for a modest period of 3 months could be effective in maintaining or enhancing pupil’s anthropometric and physiological parameters in comparison to the controls where there was deterioration in both parameters. Policy makers and secondary schools in Egypt might need to pay more attention to PA programmes conducted on school days, in order to motivate pupils to attend such programmes. There is also an urgent need to look at current PA systems within schools in Egypt in order to assess PA outside school times.

Heart rate variability (HRV) in adolescent females with anxiety disorders and major depressive disorder

Aim:

The aim of this study was to investigate heart rate variability (HRV) in a clinical sample of female adolescents with anxiety disorders (AD) and/or major depressive disorder (MDD) compared with healthy controls and to assess the effect of selective serotonin reuptake inhibitors (SSRI) on HRV.

Methods:

Heart rate variability was measured in adolescent female psychiatric patients with AD and/or MDD (n = 69), mean age 16.8 years (range: 14.5–18.4), from 13 out-patient clinics and in healthy controls (n = 65), mean age 16.5 years (range: 15.9–17.7). HRV was registered in the sitting position during 4 min with no interventions.

Results:

Logarithmically transformed high frequency HRV (HF), low frequency HRV (LF) and standard deviation of inter beat intervals (SDNN) were lower in the clinical sample compared with the controls (Cohen’s d for HF = 0.57, LF = 0.55, SDNN = 0.60). This was not explained by body mass index, blood pressure or physical activity. Medication with SSRI explained 15.5% of the total variance of HF, 3.0% of LF and 6.5% of SDNN.

Conclusions:

Adolescent female psychiatric patients with AD and/or MDD show reduced HRV compared with healthy controls. Medication with SSRI explained a part of this difference.

Heart rate variability is related to self-reported physical activity in a healthy adolescent population

This study investigated whether there is a relationship between heart rate variability (HRV) versus lifestyle and risk factors for cardiovascular disease in a population of healthy adolescents. HRV is as an index of tonic autonomic activity and in adults HRV is related to lifestyle and risk factors for cardiovascular disease, but it is not known if this is the case in adolescents. HRV was registered for 4 min in sitting position in 99 healthy adolescents (age range 15 years 11 months–17 years 7 months) and repeated after 6 months. On both occasions there were significant correlations (P < 0.05) between physical activity and HRV, with respective r values: high frequency (HF) 0.26, 0.30; low frequency power (LF) 0.35, 0.29 and the standard deviation of inter-beat intervals (SDNN) 0.28, 0.37. There was no significant interaction between first and second measurements. In contrast, there were no correlations to sleeping patterns, eating habits and smoking. Risk factors for cardiovascular disease [body mass index (BMI = weight (kg)/length in m²), systolic blood pressure and p-glucose] did not show any repeatable significant correlations to HRV. Multiple regression models showed that physical activity was a predictor for HF, LF and SDNN in both measurements. In conclusion HF, LF and SDNN were reproducible after 6 months and were related to physical activity on both occasions.

Effects of aerobic exercise training and irbesartan on blood pressure and heart rate variability in patients with chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVES

The present pilot study was undertaken to evaluate the efficacy of an aerobic exercise training (AET) program alone or combined with an antihypertensive agent (irbesartan) to reduce blood pressure (BP) and enhance heart rate variability (HRV) in chronic obstructive pulmonary disease patients.

METHODS

Twenty-one patients were randomly assigned to a double-blind treatment with exercise and placebo (n=11) or exercise and irbesartan (n=10). Subjects underwent 24 h BP monitoring and 24 h electrocardiographic recording before and after the 12-week AET. HRV was investigated using three indexes from the power spectral analysis and three indexes calculated from the time domain. The AET program consisted of exercising on a calibrated ergocycle for 30 min three times per week. Five patients in the placebo group were excluded during follow-up because they were not compliant.

RESULTS

There was no change in 24 h systolic and diastolic BP before (130+/-14 mmHg and 70+/-3 mmHg, respectively) and after (128+/-8 mmHg and 70+/-8 mmHg, respectively) exercise training in the placebo group, whereas in the irbesartan group systolic and diastolic BP decreased from 135+/-9 mmHg and 76+/-9 mmHg to 126+/-12 mmHg and 72+/-8 mmHg, respectively (P<0.02). There were no changes in HRV parameters in either group.

CONCLUSIONS

The present study suggests that a 12-week AET program is not associated with a significant reduction in BP or enhancement in HRV, whereas an AET program combined with irbesartan is associated with a reduction in 24 h BP.

Heart rate turbulence: standards of measurement, physiological interpretation, and clinical use: International Society for Holter and Noninvasive Electrophysiology Consensus

This consensus statement has been compiled on behalf of the International Society for Holter and Noninvasive Electrophysiology. It reviews the topic of heart rate turbulence (HRT) and concentrates on technologies for measurement, physiologic background and interpretation, and clinical use of HRT. It also lists suggestions for future research. The phenomenon of HRT refers to sinus rhythm cycle-length perturbations after isolated premature ventricular complexes. The physiologic pattern of HRT consists of brief heart rate acceleration (quantified by the so-called turbulence onset) followed by more gradual heart rate deceleration (quantified by the so-called turbulence slope) before the rate returns to a pre-ectopic level. Available physiologic investigations confirm that the initial heart rate acceleration is triggered by transient vagal inhibition in response to the missed baroreflex afferent input caused by hemodynamically inefficient ventricular contraction. A sympathetically mediated overshoot of arterial pressure is responsible for the subsequent heart rate deceleration through vagal recruitment. Hence, the HRT pattern is blunted in patients with reduced baroreflex. The HRT pattern is influenced by a number of factors, provocations, treatments, and pathologies reviewed in this consensus. As HRT measurement provides an indirect assessment of baroreflex, it is useful in those clinical situations that benefit from baroreflex evaluation. The HRT evaluation has thus been found appropriate in risk stratification after acute myocardial infarction, risk prediction, and monitoring of disease progression in heart failure, as well as in several other pathologies.

Biological characteristics and ageing in former elite volleyball players

To date, there is very little information about the effects of ageing and sport selection on the characteristics of former athletes. The aim of this study was to analyse anthropometric and physiological characteristics of 146 former elite volleyball players in Italy. The possible effect of an active or inactive lifestyle on ageing was assessed by comparing the biological profiles of subsamples of former athletes with and without regular sport activity. All the former athletes underwent measurements of standard anthropometry (height, sitting height and body mass; skinfold thicknesses; bi-acromial and bi-cristal breadths; upper limb length; upper arm, calf and chest girths), cardio-respiratory function (vital capacity, forced vital capacity, forced expiratory volume in 1s; systolic and diastolic blood pressures and heart rate), muscle strength (handgrip strength), and cognitive function (visual and auditory simple reaction times; Digit-Symbol subtest). Body composition parameters were estimated from anthropometric measurements. Data on lifestyle were collected by questionnaires. The results show that the former players differ from current players in several anthropometric and physiological traits. Selection pressure seems to be more responsible for these differences than ageing. This study underlines the particular performance of former players in cognitive functions. Moreover, it confirms that an active lifestyle has beneficial effects on the biological age profiles of former athletes.

Effect of age and sex on heart rate variability in healthy subjects

OBJECTIVE

The study aimed to investigate the effect of age and sex on the heart rate variability (HRV) analysis and to explore the normal range of HRV in different age and sex groups for potential health care applications.

METHOD

Baseline HRV, age, and sex data were collected from 470 subjects without cardiovascular conditions. Short-term HRV was recorded using Biocom Active ECG units (Biocom, Seattle, Wash). Subjects were divided by age into 10-year intervals and by sex for HRV analysis.

RESULTS

Total power, representing the overall autonomic activity, decreased consistently from the age groups 10+ to 80+ years (P < .001). Both the low frequency (sympathetic activity) and high frequency (parasympathetic activity) declined (P < .05) as age increased. Sex had a significant effect on heart rate, R-R interval, high frequency, normalized low frequency, normalized high frequency, and low frequency-high frequency ratio. Sex did not seem to affect the SD of the normal-to-normal heartbeats and total power (P > .05) despite the significant heart rate changes (P < .05).

CONCLUSION

This study demonstrated that age had a greater impact on HRV than sex. The older age group had consistently lower HRV than younger people. The values generated in this study may be useful in health care settings to determine abnormal ranges of HRV under different clinical and experimental conditions.

Changes in heart rate variability, quality of life, and activity in cardiac resynchronization therapy patients: results of the HF-HRV registry

BACKGROUND

Cardiac resynchronization therapy (CRT) is a viable therapy in the treatment of heart failure (HF). Heart rate variability (HRV) is a prognostic marker of HF and mortality and is a sign of autonomic dysfunction. Acute improvements in measures of HRV have been demonstrated after CRT in small clinical studies. The purpose of the present study was to evaluate changes in HRV and patient outcomes over time and the relationship between these changes in a large generalized sample of patients who received CRT with defibrillator (CRT-D).

METHODS

The Heart Failure-Heart Rate Variability (HF-HRV) registry enrolled 1,421 patients who received a CRT-D device capable of measuring HRV. Patients were followed for a 1-year period. Device diagnostics, including HRV footprint; standard deviation of averaged normal R to R intervals (SDANN); and mean, minimum, and maximum heart rate were measured at each visit, in addition to activity log, New York Heart Association (NYHA) class, and quality of life (QOL) data.

RESULTS

This large sample of HF patients showed an overall improvement in SDANN (69.2 +/- 25.5, 78.5 +/- 27.8, 79.4 +/- 27.2, 80.7 +/- 28.2) and HRV footprint (31.5 +/- 11.8, 33.4 +/- 12.3, 34.2 +/- 12.2, 34.5 +/- 12.3) at the 2 week, 3 month, 6 month, and 12 month visits, respectively (both P < 0.001). There were also significant changes over time in clinical status (improved QOL, increased activity, and improved NYHA, all P < 0.0001), with the greatest changes occurring between the 2 week and 3 month visits.

CONCLUSION

In conclusion, these study results demonstrate that device measured HRV parameters and patient outcomes significantly improve after receipt of CRT.

Effects of age on ventilatory threshold and peak oxygen uptake normalised for regional skeletal muscle mass in Japanese men and women aged 20–80 years

Ventilatory threshold (VT) is an important predictor of cardiorespiratory fitness, such as peak oxygen uptake (VO2peak) and is a valuable index of aerobic exercise intensity. However, little is known about the role of skeletal muscle (SM) mass in the age-associated decline of VT. Therefore, the present study was performed to investigate the effects of age on cardiopulmonary fitness normalised for regional SM mass in 1,463 Japanese men and women, and to determine the relevance of VT normalised to SM mass based on age and gender. Total, trunk and thigh SM mass were measured using an ultrasound method, while VO2peak and VT were determined during treadmill walking. VO2peak was estimated using the predicted maximum heart rate (HR) and the HR-VO2 relationship for sub-maximal treadmill walking. There were significant negative correlations between VT normalised for body mass and age in men and women (P < 0.001). Age-associated declines were also observed in VT normalised for body mass in both men and women; however, VT normalised for SM mass was not significantly different with age. Significant correlations were also observed between thigh SM mass and VT in both men and women. These results suggest that thigh SM mass is closely associated with VO2peak and/or VT in both men and women, and the decrease in VT with age is predominantly due to an age-related decline of SM mass. Moreover, this study provides normative cardiorespiratory fitness data regarding VT normalised SM mass in healthy men and women aged 20-80 years.

The use of heart rate variability measures to assess autonomic control during exercise

Heart rate variability (HRV) is a non-invasive indicator of cardiac autonomic modulation at rest. During rhythmic exercise, global HRV decreases as a function of exercise intensity. Measures reflecting sympathovagal interactions at rest do not behave as expected during exercise. This makes interpretation of HRV measures difficult, especially at higher exercise intensities. This problem is further confounded by the occurrence of non-neural oscillations in the high-frequency band due to increased respiratory effort. Alternative data treatments, such as coarse graining spectral analysis (CGSA), have demonstrated expected changes in autonomic function during exercise with some success. The separation of harmonic from fractal and/or chaotic components of HRV and study of the latter during exercise have provided further insight into cardioregulatory control. However, more research is needed. Some cross-sectional differences between HRV in athletes and controls during exercise are evident and data suggest longitudinal changes may be possible. Standard spectral HRV analysis should not be applied to exercise conditions. The use of CGSA and non-linear analyses show much promise in this area. Until further validation of these measures is carried out and clarification of the physiological meaning of such measures occurs, HRV data regarding altered autonomic control during exercise should be treated with caution.