Relationship between Daily Physical Activity and ANS Activity in Patients with CHF

Effects of transcranial direct current stimulation on heart rate variability: a systematic review protocol

OBJECTIVE

This systematic review aims to synthesize the available evidence on the effects of transcranial direct current stimulation on heart rate modulation, indexed by heart rate variability parameters in healthy individuals and those with clinical disorders.

INTRODUCTION

There is some evidence that altered heart rate variability parameters are associated with different clinical disorders. For example, diminished parasympathetic activity has been explored as a potential biomarker for some chronic pain conditions. Considering the dynamic interaction between brain and heart, neuromodulatory strategies targeting this relationship could exert a positive influence on the cardiac autonomic system. Transcranial direct current stimulation is a non-invasive neuromodulation technique that has been presenting recent advances in the treatment of various clinical disorders. However, the evidence concerning transcranial direct current stimulation application focusing on brain-heart interaction is still controversial.

INCLUSION CRITERIA

This review will consider studies that investigate the effects of transcranial direct current stimulation on heart rate variability in healthy participants or those with clinical disorders.

METHODS

This review will follow JBI systematic review methodology recommendations. PubMed, Embase, CINAHL, Web of Science, PsycNET, Cochrane Controlled Register of Trials (CENTRAL) and Physiotherapy Evidence Database (PEDro) will be searched, along with several sources of gray literature. Retrieval of full-text studies, and assessment of methodological quality and data extraction, will be performed independently by two reviewers. Data will be pooled in statistical meta-analysis, where possible.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42018114105.

Association Between Occupational, Sport, and Leisure Related Physical Activity and Baroreflex Sensitivity

Physical activity (PA) is a preventative behavior for noncommunicable disease. However, little consideration is given as to whether different domains of PA have differing associations with health outcomes. We sought to determine the association between occupational, sport, leisure, and total PA with baroreflex sensitivity (BRS), distinguishing between neural (nBRS) and mechanical (mBRS) BRS. In a cross-sectional analysis of 8649 adults aged 50 to 75 years, resting nBRS (estimated by low-frequency gain, from carotid distension rate and heart rate) and mBRS (carotid stiffness) were measured by high-precision carotid echo-tracking. PA was self-reported using the validated Baecke questionnaire. The associations between PA and nBRS and mBRS were quantified using multivariate linear regression analysis, separately in the working and nonworking population. In working adults (n=5039), occupational PA was associated with worse nBRS (unstandardized β=−0.02; [95% CI, −0.04 to −0.003]; P =0.022) whereas sport PA was associated with better nBRS (β=0.04; [95% CI, 0.02–0.07]; P =0.003) and mBRS (β=−0.05; [95% CI, −0.09 to −0.00001]; P =0.049). Neither leisure PA nor total PA was associated with nBRS or mBRS. In nonworking adults (n=3610), sport PA and total PA were associated with better mBRS (β=−0.08; [95% CI, −0.15 to 0.02]; P =0.012 and β=−0.05; [95% CI, −0.10 to 0.009]; P =0.018) but not nBRS. These findings suggest differential associations between domains of PA and BRS and may provide insights into the mechanisms underlying the association between occupational PA and cardiovascular disease.

Accelerometer-Measured Daily Activity Levels and Related Factors in Patients With Heart Failure

BACKGROUND

Few studies report objective accelerometer-measured daily physical activity levels in patients with heart failure (HF).

OBJECTIVE

We examined baseline accelerometer-measured physical activity from the Heart Failure Exercise and Resistance Training Camp trial, a federally funded (R01-HL112979) 18-month intervention study to promote adherence to exercise in patients with HF. Factors associated with physical activity levels were also explored.

METHODS

Patients with diagnosed HF (stage C chronic HF confirmed by echocardiography and clinical evaluation) were recruited from 2 urban medical centers. Physical activity energy expenditure and the number of minutes of moderate or vigorous physical activity (MVPA) were obtained from 7 full days of measurement with the accelerometer (Actigraph Model GT3X, Pensacola, Florida) for 182 subjects who met minimum valid wear time parameters. Additional measures of health-related factors were included to explore the association with physical activity levels.

RESULTS

Subjects had 10.2 ± 10.5 minutes of MVPA per day. Total physical activity energy expenditure was 304 ± 173 kcal on average per day. There were 23 individuals (12.6%) who met the recommended goal of 150 minutes of MVPA per week. Men, whites, New York Heart Association class II, and subjects with better physical function had significantly higher levels of activity.

CONCLUSIONS

Consistent with previous research, patients with HF are not meeting recommended guidelines for 150 minutes of MVPA per week.

The Interaction Analysis between the Sympathetic and Parasympathetic Systems in CHF by Using Transfer Entropy Method

Congestive heart failure (CHF) is a cardiovascular disease associated with autonomic dysfunction, where sympathovagal imbalance was reported in many studies using heart rate variability (HRV). To learn more about the dynamic interaction in the autonomic nervous system (ANS), we explored the directed interaction between the sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS) with the help of transfer entropy (TE). This article included 24-h RR interval signals of 54 healthy subjects (31 males and 23 females, 61.38 ± 11.63 years old) and 44 CHF subjects (8 males and 2 females, 19 subjects' gender were unknown, 55.51 ± 11.44 years old, 4 in class I, 8 in class II and 32 in class III~IV, according to the New York Heart Association Function Classification), obtained from the PhysioNet database and then segmented into 5-min non-overlapping epochs using cubic spline interpolation. For each segment in the normal group and CHF group, frequency-domain features included low-frequency (LF) power, high-frequency (HF) power and LF/HF ratio were extracted as classical estimators of autonomic activity. In the nonlinear domain, TE between LF and HF were calculated to quantify the information exchanging between SNS and PNS. Compared with the normal group, an extreme decrease in LF/HF ratio (p = 0.000) and extreme increases in both TE(LF→HF) (p = 0.000) and TE(HF→LF) (p = 0.000) in the CHF group were observed. Moreover, both in normal and CHF groups, TE(LF→HF) was a lot greater than TE(HF→LF) (p = 0.000), revealing that TE was able to distinguish the difference in the amount of directed information transfer among ANS. Extracted features were further applied in discriminating CHF using IBM SPSS Statistics discriminant analysis. The combination of the LF/HF ratio, TE(LF→HF) and TE(HF→LF) reached the highest screening accuracy (83.7%). Our results suggested that TE could serve as a complement to traditional index LF/HF in CHF screening.

Psychological and autonomic effects of art making in college-aged students

BACKGROUND AND OBJECTIVES

Anxiety disorders comprise the most common category of mental illness among US young adults. Art making might be one method to help reduce anxiety, but the few studies investigating this have used only subjective measures of anxiety.

DESIGN

This study employed both subjective (self-reported state anxiety from the State-Trait Anxiety Inventory) and objective (heart rate variability) measures to assess whether 30-minute periods of art making reduced anxiety in 47 first-year college students prior to their final examinations.

METHODS

Students participated in free-form painting, mandala coloring, clay modeling, and control sessions.

RESULTS

Repeated-measures ANOVA with post hoc analysis revealed significantly greater pre- to post-session reductions in anxiety for all three types of art-making sessions than for the control session, as measured objectively. Measured subjectively, only free-form painting yielded a significant decrease in anxiety compared to the control session.

CONCLUSIONS

Given the health benefits of anxiety reduction, further study is warranted to determine the duration of art making's anxiety-reducing effect.

Physical activity and heart rate variability in older adults: the Cardiovascular Health Study

BACKGROUND

Cardiac mortality and electrophysiological dysfunction both increase with age. Heart rate variability (HRV) provides indices of autonomic function and electrophysiology that are associated with cardiac risk. How habitual physical activity among older adults prospectively relates to HRV, including nonlinear indices of erratic sinus patterns, is not established. We hypothesized that increasing the levels of both total leisure-time activity and walking would be prospectively associated with more favorable time-domain, frequency-domain, and nonlinear HRV measures in older adults.

METHODS AND RESULTS

We evaluated serial longitudinal measures of both physical activity and 24-hour Holter HRV over 5 years among 985 older US adults in the community-based Cardiovascular Health Study. After multivariable adjustment, greater total leisure-time activity, walking distance, and walking pace were each prospectively associated with specific, more favorable HRV indices, including higher 24-hour standard deviation of all normal-to-normal intervals (Ptrend=0.009, 0.02, 0.06, respectively) and ultralow-frequency power (Ptrend=0.02, 0.008, 0.16, respectively). Greater walking pace was also associated with a higher short-term fractal scaling exponent (Ptrend=0.003) and lower Poincaré ratio (Ptrend=0.02), markers of less erratic sinus patterns.

CONCLUSIONS

Greater total leisure-time activity, and walking alone, as well, were prospectively associated with more favorable and specific indices of autonomic function in older adults, including several suggestive of more normal circadian fluctuations and less erratic sinoatrial firing. Our results suggest potential mechanisms that might contribute to lower cardiovascular mortality with habitual physical activity later in life.

Sleep apnea and cognitive function in heart failure

Background. Prior research indicates that heart failure (HF) patients exhibit significant cognitive deficits on neuropsychological testing. Sleep apnea is associated with both HF and reduced cognitive function, but the combined impact of these conditions on cognitive function is unknown. Methods. In the current study, 172 older adults with a dual diagnosis of HF and sleep apnea or HF alone completed a battery of cognitive tests measuring attention, executive functioning, and memory. Results. Relative to patients with HF alone, persons with both HF and sleep apnea performed worse on measures of attention after adjusting for demographic and medical variables. Conclusions. The current findings suggest that HF patients with comorbid sleep apnea may be at greater risk for cognitive impairment relative to HF patient without such history. Further work is needed to clarify mechanisms for these findings and to determine whether the interactive effects on cognitive function lead to poorer patient outcomes.

Aerobic exercise training improves autonomic nervous control in patients with COPD

OBJECTIVES

Autonomic modulation is adversely impacted in patients with chronic obstructive pulmonary disease (COPD). The purpose of the present investigation is to assess the effects of a 6-week aerobic exercise training program on autonomic modulation of heart rate in patients with COPD.

METHODS

Forty patients of both sexes with moderate-to-severe COPD were randomly allocated to aerobic exercise training (PT, n=20) or to usual care (Control, n=20). The training program consisted of lower and upper limb stretching and 30 min of treadmill exercise, 3 times per week for a 6-week period. Physiological data during symptom-limited exercise testing and the six-minute walk test (6MWT) were assessed. In addition, R-R intervals were obtained at rest and during the 6MWT. Heart rate variability was analyzed by time (rMSSD and SDNN index) and frequency domains (high frequency--HF, low frequency--LF and HF/LF ratio).

RESULTS

Peak oxygen consumption significantly improved in the training group only (p<0.05). Moreover, the training group demonstrated significant improvements (p<0.05) in blood lactate, minute ventilation, dyspnea at peak exercise, sympathetic activity, and parasympathetic activity at rest and during submaximal exercise. Lastly, a positive and significant correlation was found between change in 6MWT distance and rMSSD index (r=0.65 and p=0.001).

CONCLUSIONS

Neural control of heart rate, in addition to other clinically valuable measures, is positively altered in moderate-severe COPD patients following 6 weeks of aerobic exercise training. The improvement in submaximal performance after exercise training was associated with parasympathetic activity.

Longitudinal cognitive performance in older adults with cardiovascular disease: evidence for improvement in heart failure

BACKGROUND

Cardiovascular disease (CVD) and particularly heart failure (HF) have been associated with cognitive impairment in cross-sectional studies, but it is unclear how cognitive impairment progresses over time in older adults with these conditions.

OBJECTIVE

The aim of this study was to prospectively examine cognitive function in patients with HF versus other forms of CVD.

METHOD

Seventy-five older adults (aged 53-84 years) with CVD underwent Doppler echocardiogram to evaluate cardiac status and 2 administrations of the Dementia Rating Scale (DRS), a test of global cognitive functioning, 12 months apart.

RESULTS

Although DRS performance did not statistically differ between groups at either administration, a significant between-group difference in the rate of cognitive change emerged (lambda = 0.87; F = 10.50; P = .002; omega 2 = 0.11). Follow-up analyses revealed that patients with HF improved significantly on global DRS performance, whereas patients with other forms of CVD remained stable. More specifically, patients with HF showed improvement on subscales of attention, initiation/perseveration, and conceptualization. Exploratory analyses indicated that higher diastolic blood pressure at baseline was associated with improved DRS performance in patients with HF (r = 0.38; P = .02).

CONCLUSIONS

Patients with HF exhibited modest cognitive improvements during 12 months, particularly in attention and executive functioning. Higher diastolic blood pressure at baseline was associated with improvement. These results suggest that cognitive impairment in patients with HF may be modifiable and that improved blood pressure control may be an important contributor to improved function. Further prospective studies are needed to replicate results and determine underlying mechanisms.

Effects of daily physical activity level on the degree of sympathetic tone

BACKGROUND

Exercise is recommended for the treatment and prevention of cardiac disorders. Relaxation of the sympathetic nervous system has been considered to be one of the therapeutic mechanisms. However, the means by which the level of daily physical activity affects sympathetic activity remains unclear.

OBJECTIVE

To evaluate the effects of daily physical activity on autonomic nervous tone.

METHODS

Daily physical activity was measured for 5 or more days in 26 patients with various cardiac disorders of NYHA class 1 or 2 and in 6 healthy individuals using an intelligent calorie counter. Recumbent resting ECG was recorded for 3 minutes immediately before waking up and after going to bed using a digital ECG. Low- (Lf, 0.03-0.15 Hz) and high- (Hf, 0.15-0.45 Hz) frequency components were calculated by frequency analysis of the R-R interval, and Lf/Hf ratio was calculated as an index of sympathetic tone.

RESULTS

The average values of energy expenditure and time were 145+/-93.6 kcal/day and 47.8+/-24.3 min/day, respectively. The morning Lf/Hf ratio decreased following an increased physical activity level the day before, but increased with subsequent increase in the activity level in 65.6% of subjects. A negative correlation was observed in 34.4% of subjects, which suggested that an appropriate level of physical activity led to relaxation of sympathetic tone.

CONCLUSION

The daily level of physical activity affects sympathetic tone, and an appropriate level results in sympathetic relaxation. The results of this study provide a useful index to enable patients with cardiac disorder to perform exercise without overloading.

Exercise training for patients with cardiovascular disease

This review surveys effort training, a validated and recommended therapy, in patients with atheromatous cardiovascular disease. This true therapy reduces mortality by 25-35%, reduces clinical manifestations and complications (rhythm problems, thrombosis) and improves physical capacity, reintegration and quality of life. The effects are essentially linked to improved metabolic performance of muscles and reduced endothelial dysfunction, insulin resistance and neurohormonal abnormalities. Training also has an impact on the evolution of major risk factors, especially diabetes and arterial hypertension. The risks are limited as long as the contraindications are respected and the programmes supervised. The indications (stable angina, chronic heart failure, peripheral arterial disease) should be described more precisely by taking into account functional criteria: physical deconditioning, exclusion, compliance, mood swings, and seriousness of risk factors. The training programme should be tailor made and based on evaluation of the patient's adaptation to effort, in terms of frequency, intensity and duration of the exercises. Various types of exercise include overall or segmental physical training; concentric, eccentric, even isokinetic muscle contraction exercises; and proprioceptive rehabilitation. However, knowledge is lacking about the molecular mechanisms of the effects of training, the most effective intensity of effort, and strategies to develop physical activity in this ever-growing population for both primary and secondary prevention.

Peak anaerobic power in patients with COPD: gender related differences

The aim of the study was to investigate peak anaerobic power during all-out exercise in patients with COPD. Twenty patients (ten women, ten men) [FEV1=50.5 (7.6)% of predicted] and 11 healthy subjects (six women, five men) performed: (1) three maximal sprints on a cycle ergometer to measure peak anaerobic power (Pmax) and optimal velocity (Vopt), (2) assessment of whole-body composition by dual-energy X-ray absorptiometry (DEXA) and (3) assessment of mean habitual daily energy expenditure (MHDEE). Pmax was 30% lower in COPD than in healthy subjects [22.9 (7.1) vs. 32.8 (5.6) W kg-1 (legs FFM), P<0.001]. Nevertheless, Vopt was similar in both series. In COPD, Pmax was lower in women than in men [21.4 (7.7) vs. 23.8(6.4) W kg-1 (legs FFM), P<0.05]. Vopt was lower in women than in COPD men [72.6 (11.3) vs. 89.3 (13.8) rpm, P<0.05]. MHDEE was lower in COPD than in healthy subjects [8019 (1254) vs. 9093 (1660) kJ day-1]. In COPD, MHDEE was lower in women than in men (P<0.001). This study demonstrates that in COPD patients, the decrease in peak anaerobic power could play a role in their specific muscular dysfunction. Considerable differences were observed in peripheral muscle function, body composition and MHDEE between women and men. The skeletal muscle of women and men may therefore adapt to COPD in different ways.