Inter- and intrarater reliability of short-term measurement of heart rate variability on rest in chronic obstructive pulmonary disease (COPD).

BACKGROUND: Individuals with COPD have an imbalance of cardiac autonomic control. In this context, HRV is considered an important tool for assessing cardiac sympathetic and parasympathetic balance, however it is a dependent evaluator measure and subject to methodological biases that may compromise the interpretation of results. OBJECTIVE: This study examines the inter- and intrarater reliability of HRV parameters derived from short-term recordings in individuals with COPD. METHODOLOGY: Fifty-one individuals of both genders with COPD clinical diagnosis confirmed by the pulmonary function test and aged ≥50 years were included. The RR interval (RRi) were recorded during a 10 min period on supine position using a portable heart rate monitor (Polar® H10 model). The data were transferred into Kubios® HRV Standard analysis software and analyzed within the stable sessions containing 256 sequential RRi. RESULTS: The intraclass correlation coefficient (ICC) ranged from 0.942 to 1.000 according to the intrarater analysis by Researcher 01 and 0.915 to 0.998 to the intrarater by Researcher 02. The interrater ICC ranged from 0.921 to 0.998. The coefficient of variation was up to 8.28 for Researcher 01 intrarater analysis, 9.06 for Researcher 02 intrarater analysis and 13.07 for interrater analysis. CONCLUSION: The measurement of HRV using a portable heart rate device in individuals with COPD present acceptable values of intra- and interrater reliability, supporting the use of HRV in the clinical and scientific scenario. Furthermore, it is important that the data analysis be performed by the same experienced evaluator.

Acute whole-body electromyostimulation associated with dynamic exercises did not alter cardiac autonomic modulation and oxygen uptake in obese and eutrophic men

Abstract Aim: To contrast the acute effects of whole-body electromyostimulation (WB-EMS) with sham associated with dynamic exercises on cardiovascular, ventilatory, metabolic, and autonomic responses in men with obesity and controls. Methods: A randomized cross-over and double-blind trial with nine eutrophic (23.6 years; 23 ± 1.4 kg/m2) and ten men with obesity (26 ± 4 years; 38 ± 7 kg/m2), who were randomized to receive WB-EMS-Sham or Sham-WB-EMS with 30 min of rest between protocols. WB-EMS protocol (Miha Bodytec®) was applied at the motor level, frequency = 85 Hz, pulse duration = 350 μs, cycle on = 6′; cycle off = 4′. Sham group performed the same exercises with the electric current turned off. Throughout both protocols, subjects executed two dynamic exercises of 5 minutes each (step-up and step down associated with shoulder flexion, and lunge exercise associated with elbow flexion) in the same order. R-R intervals and breath-by-breath respiratory gases analysis were collected during the protocols. Heart rate variability (HRV) indexes were obtained using linear and nonlinear analysis. The level of statistical significance was set at p < 0.05. Results: Regarding both exercises, participants with obesity presented reduced oxygen uptake, higher ventilation, respiratory rate, blood pressure, and Borg scores (p < 0.05) when contrasted with controls, as expected. However, no significant differences were found for HRV indexes between groups (p > 0.05). In addition, WB-EMS did not increase oxygen uptake or altered autonomic modulation when contrasted with sham in both groups (p < 0.05). Conclusion: Obesity has a negative impact on symptoms and functional capacity. However, WB-EMS did not acutely enhance oxygen uptake or HRV during exercise in a population with obesity.

Responses of different functional tests in candidates for bariatric surgery and the association with body composition, metabolic and lipid profile.

Individuals with obesity can have metabolic disorders and may develop impairments that affect the ability to exercise. The maximal incremental cardiopulmonary exercise test is widely used to assess functional capacity. However, submaximal tests such as the two-minute step test (2MST) and the six-minute walk test (6MWT) also allow this assessment. We propose to analyze whether body composition, metabolic and lipid profile influence the maximal and submaximal performance, and investigate these variables in response to different functional tests. Forty-four individuals with obesity, aged 18-50 years, underwent analysis of body composition, metabolic and lipid profile, incremental treadmill test (ITMT), 6MWT, and 2MST. One-way ANOVA, Pearson or Spearman correlation, and Stepwise multiple linear regression analysis were performed. ITMT induced a greater metabolic, ventilatory, cardiovascular, and perceived exertion demand when compared to the 6MWT and 2MST (p < 0.05). In addition, 2MST elicited a higher chronotropic (HR) and metabolic (V̇O2) demand when compared to the 6MWT (p < 0.05). Significant correlations were found between tests and body composition, metabolic and lipid profile. Fat mass and low-density lipoprotein can explain 30% of the V̇O2 variance in the ITMT; and fat mass, glucose, and performance in the 2MST can explain 42% of the variance of the distance walked in the ITMT. Obesity and its metabolic impairments are capable of influencing responses to exercise. ITMT generated greater demand due to the high stress imposed, however, 2MST demanded greater metabolic and chronotropic demand when compared to the 6MWT.

Whole-body electrical stimulation as a strategy to improve functional capacity and preserver lean mass after bariatric surgery: a randomized triple-blind controlled trial.

BACKGROUND/OBJECTIVES: Bariatric surgery (BS) is a successful, long-lasting treatment option for obese. The early postoperative (PO) period is followed by dietary restriction and physical inactivity, leading to declines in muscle mass and functional capacity. Whole-body electromyostimulation (WB-EMS) may be a feasible and potential early rehabilitation strategy post BS. The aim was to evaluate the effects of WB-EMS with exercise training (Fe) on functional capacity, body composition, blood biomarkers, muscle strength, and endurance post BS. SUBJECTS/METHODS: This is a randomized, triple-blind, sham-controlled trial. Thirty-five volunteers underwent a Roux-en-Y gastric bypass and were randomized into a WB-EMS (WB-EMSG) or control group (ShamG). Preoperative evaluations consisted of maximal and submaximal exercise testing, body composition, blood biomarkers, quadriceps strength, and endurance. After discharge, functional capacity and body composition were obtained. Exercise training protocols in both groups consisted of 14 dynamic exercises, 5 days per week, completing 30 sessions. The WB-EMSG also underwent an electrical stimulation protocol (Endurance: 85 Hz, 350 ms, 6 s of strain, 4 f of rest; Strength: 30 Hz, 350 ms, 4 s of strain, 10 seconds of rest, with bipolar electrical pulse). After intervention, subjects were reevaluated. RESULTS: The protocol started on average 6.7 ± 3.7 days after discharge. Both groups presented with a decline in functional capacity after BS (p < 0.05) and a reduction in all body composition measurements (p < 0.05). The exercise training program led to significant improvements in functional capacity (ShamG - PO: 453.8 ± 66.1 m, Post: 519.2 ± 62.8 m; WB-EMSG- PO: 435.9 ± 74.5, Post: 562.5 ± 66.4 m, p < 0.05), however, only the WB-EMSG demonstrated significant changes of distance walked (interaction time vs group effect, p < 0.05). In addition, adiponectin significantly increased only in the WB-EMSG (p < 0.05). The WB-EMSG was also able to preserve muscle strength, endurance, and fatigue index, while the ShamG demonstrated significant decline (p < 0.05). CONCLUSION: WB-EMS + Fe can be an attractive and feasible method following BS to enhance functional capacity and prevent deterioration of muscle function in the early PO. CLINICAL TRIAL REGISTRATION: ReBEC, RBR-99qw5h, on 20 February 2015.

Validity, intra and inter-reliability of manual evaluation of the respiratory muscle strength in asthmatic patients.

OBJECTIVE: This study investigated the concurrent validity, inter and intra-reliability of manual evaluation in Asthma patients. METHODS: Twenty six asthma patients were assessed. Maximal respiratory muscle strength (Mrms) was tested by inspiratory and expiratory pressure (MIP and MEP, respectively) trough manovacuometer. In addition, Mrms of diaphragm (anterior and posterior), Intercostals (lower and upper portion) and Rectus abdominal were obtained manually, according to Medical Research Council (MRC) scale. Two independents evaluators, previously trained, made both measurements. RESULTS: Reproducibility of Mrms intra-evaluators: anterior diaphragm (ICCs, 0.79 and 0.67); Posterior portion of the diaphragm (ICCs, 0.43 and 0.51); Upper intercostals (ICCs, 0.47 and 0.40); Lower intercostals (ICCs, 0.81 and 0.51) and rectus abdominal (ICCs, 1.0). Inter-reproducibility of anterior diaphragm was low to moderate, while intercostals (upper and lower portion) was relatively low. However, rectus abdominal presented high reproducibility reflecting in almost perfect agreement. In addition, we found positive correlations between MIP versus Lower Intercostals (r = .60, p = .007) and MEP versus rectus abdominal (r = .41, p = .04). CONCLUSION: In asthmatic patients, manual evaluation of the respiratory muscles is reliable. In addition, maximal respiratory pressures using manometer assessment were related to manual evaluation, in special to diaphragm and rectus abdominal muscles.

Effects of Whole-Body Electromyostimulation Associated with Dynamic Exercise on Functional Capacity and Heart Rate Variability After Bariatric Surgery: a Randomized, Double-Blind, and Sham-Controlled Trial.

PURPOSE: Bariatric surgery is the most effective treatment for morbid obesity. In association with dietary restrictions, the ability to exercise in the immediate post-surgical phase is limited. In this context, whole-body electromyostimulation (WB-EMS), strategy that stimulates various muscle groups, in conjunction with physical exercise, holds promise for improving functional capacity, and cardiac autonomic control, following surgery. The purpose of this study was to analyze whether a rehabilitation program consisting of WB-EMS with 30 exercise training sessions following bariatric surgery significantly improves functional capacity, body mass and heart rate variability (HRV). METHODS: Randomized, double-blind, and sham-controlled trial. Twenty obesity patients were randomized into the WB-EMS (n = 10) and sham (n = 10) groups. On average, 7 days after surgery, individuals underwent a six-minute walk test (6MWT), HRV, and body composition analysis at rest. The next day, patients initiated an exercise training protocol, five times per week, over 6 weeks. Walking distance changes (post-pre = ΔWD) obtained by 6MWT and HRV indices were determined following the intervention. RESULTS: Only WB-EMSG significantly increased WD and body mass index (BMI) after the intervention (p = 0.002) and ΔWD was significantly higher in this group when compared with sham (p = 0.04). Moreover, both groups demonstrated an improvement in key measures of HRV after the intervention. CONCLUSION: An exercise training intervention initiated shortly after bariatric surgery improved functional capacity and cardiac autonomic tone. Improvements in functional capacity and BMI following exercise training were greater with the addition of WB-EMS but did not promote additional improvements in HRV beyond that realized with exercise training alone.

Effects of inspiratory muscle training in professional women football players: a randomized sham-controlled trial.

This study was conducted to determine the effects of inspiratory muscle training (IMT) on respiratory and peripheral muscles oxygenation during a maximal exercise tolerance test and on repeated-sprint ability (RSA) performance in professional women football players. Eighteen athletes were randomly assigned to one of the following groups: SHAM (n = 8) or IMT (n = 10). After a maximal incremental exercise test, all participants performed (on a different day) a time-to-exhaustion (Tlim) test. Peripheral and respiratory muscles oxygenation by near-infrared spectroscopy, breath-by-breath ventilatory and metabolic variables, and blood lactate concentration were measured. The RSA test was performed on a grass field. After a 6 week intervention, all athletes were reevaluated. Both groups showed increases in inspiratory muscles strength, exercise tolerance and RSA performance, however only the IMT group presented lower deoxyhemoglobin and total hemoglobin blood concentrations on intercostal muscles concomitantly to an increased oxyhemoglobin and total hemoglobin blood concentrations on vastus lateralis muscle during Tlim. In conclusion, these results may indicate the potential role of IMT to attenuate inspiratory muscles metaboreflex and consequently improve oxygen and blood supply to limb muscles during high-intensity exercise, with a potential impact on inspiratory muscle strength, exercise tolerance and sprints performance in professional women football players.

Hippotherapy acute impact on heart rate variability non-linear dynamics in neurological disorders.

Neurological disorders are associated with autonomic dysfunction. Hippotherapy (HT) is a therapy treatment strategy that utilizes a horse in an interdisciplinary approach for the physical and mental rehabilitation of people with physical, mental and/or psychological disabilities. However, no studies have been carried out which evaluated the effects of HT on the autonomic control in these patients. Therefore, the objective of the present study was to investigate the effects of a single HT session on cardiovascular autonomic control by time domain and non-linear analysis of heart rate variability (HRV). The HRV signal was recorded continuously in twelve children affected by neurological disorders during a HT session, consisting in a 10-minute sitting position rest (P1), a 15-minute preparatory phase sitting on the horse (P2), a 15-minute HT session (P3) and a final 10-minute sitting position recovery (P4). Time domain and non-linear HRV indices, including Sample Entropy (SampEn), Lempel-Ziv Complexity (LZC) and Detrended Fluctuation Analysis (DFA), were calculated for each treatment phase. We observed that SampEn increased during P3 (SampEn=0.56±0.10) with respect to P1 (SampEn=0.40±0.14, p<0.05), while DFA decreased during P3 (DFA=1.10±0.10) with respect to P1 (DFA=1.26±0.14, p<0.05). A significant SDRR increase (p<0.05) was observed during the recovery period P4 (SDRR=50±30ms) with respect to the HT session period P3 (SDRR=30±10ms). Our results suggest that HT might benefit children with disabilities attributable to neurological disorders by eliciting an acute autonomic response during the therapy and during the recovery period.