The primary objective of this study was to investigate whether noninvasive ventilation (NIV) can positively affect exercise capacity, maximum oxygen uptake (V̇
), and symptoms after a 6-week physical ...training program for subjects with moderate to very severe COPD.
47 subjects with COPD who were enrolled in a physical training program were randomized to either physical training alone or NIV + physical training (NIV-Physical training). Physical training consisted of dynamic aerobic exercises on a treadmill 3 times/week for 6 weeks, for a total of 18 sessions. NIV was titrated according to the subject's tolerance at rest and during exercise. Assessments included physiological responses and symptoms at the incremental cardiopulmonary exercise test peak and during submaximal exercise on a treadmill, 6-min walk distance, maximum inspiratory (P
) and expiratory pressure (P
), BODE index, and health-related quality of life.
43 subjects completed the 6-week physical training program. Both groups improved 6-min walk distance, P
, BODE index, and quality of life, and no differences were found between groups. However, significant improvements were observed for subjects in the NIV-Physical training group with regard to P
, maximum V̇
, maximum metabolic equivalents, circulatory power, and maximum S
.
A 6-week physical training program alone can improve tolerance for exercise and quality of life, in addition to reducing the risk of mortality. However, NIV associated with a physical training program was shown to have an additive beneficial effect on powerful prognostic markers (maximum V̇
and circulatory power) and to reduce symptoms and improve oxygen saturation in subjects with moderate to very severe COPD.
Abstract 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 ± 30 ms) with respect to the HT session period P3 (SDRR = 30 ± 10 ms). 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.
The study was conducted to determine the impact of chronic obstructive pulmonary disease (COPD) in association with obstructive sleep apnea syndrome (OSAS) on cardiac autonomic control and functional ...capacity.
The study was a cross-sectional prospective controlled clinical study. Heart rate variability indices of 24 COPD (n = 12) and COPD+OSAS (n = 12) patients were evaluated and compared by electrocardiographic recordings acquired during rest, active postural maneuver (APM), respiratory sinus arrhythmia maneuver (RSA-m), and the 6-minute walk test (6MWT).
The COPD group presented higher parasympathetic modulation during APM when compared to the COPD+OSAS group (
= 0.02). The COPD+OSAS group presented higher sympathetic modulation during RSA-m when compared to the COPD group (
= 0.00). The performance during 6MWT was similarly impaired in both groups, despite the greater severity of the COPD group.
Subjects with COPD+OSAS present marked sympathetic modulation, and the presence of OSAS in COPD subjects has a negative impact on functional capacity regardless of the severity of lung disease.
Chronic obstructive pulmonary disease (COPD) is recognized as a multisystemic inflammatory disease associated with extrapulmonary comorbidities, including respiratory muscle weakness and ...cardiovascular and cardiac autonomic regulation disorders. We investigated whether alterations in respiratory muscle strength (RMS) would affect cardiac autonomic modulation in COPD patients.
This study was a cross-sectional study done in ten COPD patients affected by moderate to very severe disease. The heart rate variability (HRV) signal was recorded using a Polar cardiofrequencimeter at rest in the sitting position (10 minutes) and during a respiratory sinus arrhythmia maneuver (RSA-M; 4 minutes). Linear analysis in the time and frequency domains and nonlinear analysis were performed on the recorded signals. RMS was assessed using a digital manometer, which provided the maximum inspiratory pressure (PImax) and the maximum expiratory pressure (PEmax).
During the RSA-M, patients presented an HRV power increase in the low-frequency band (LFnu) (46.9±23.7 vs 75.8±27.2; P=0.01) and a decrease in the high-frequency band (HFnu) (52.8±23.5 vs 24.0±27.0; P=0.01) when compared to the resting condition. Significant associations were found between RMS and HRV spectral indices: PImax and LFnu (r=-0.74; P=0.01); PImax and HFnu (r=0.74; P=0.01); PEmax and LFnu (r=-0.66; P=0.01); PEmax and HFnu (r=0.66; P=0.03); between PEmax and sample entropy (r=0.83; P<0.01) and between PEmax and approximate entropy (r=0.74; P=0.01). Using a linear regression model, we found that PImax explained 44% of LFnu behavior during the RSA-M.
COPD patients with impaired RMS presented altered cardiac autonomic control, characterized by marked sympathetic modulation and a reduced parasympathetic response; reduced HRV complexity was observed during the RSA-M.
Background: Chronic obstructive pulmonary disease (COPD) manifests itself in complex ways, with local and systemic effects; because of this, a multifactorial approach is needed for disease ...evaluation, in order to understand its severity and impact on each individual. Thus, our objective was to study the correlation between easily accessible variables, usually available in clinical practice, and maximum aerobic capacity, and to determine models for peak oxygen uptake (VO2peak) estimation in COPD patients. Subjects and methods: Individuals with COPD were selected for the study. At the first visit, clinical evaluation was performed. During the second visit, the volunteers were subjected to the cardiopulmonary exercise test. To determine the correlation coefficient of VO2peak with forced expiratory volume in 1 second (FEV1) (% pred.) and the COPD Assessment Test score (CATs), Pearson or Spearman tests were performed. VO2 at the peak of the exercise was estimated from the clinical variables by simple and multiple linear regression analyses. Results: A total of 249 subjects were selected, 27 of whom were included after screening (gender: 21M/5F; age: 65.0±7.3 years; body mass index: 26.6±5.0 kg/m2; FEV1 (% pred.): 56.4±15.7, CAT: 12.4±7.4). Mean VO2peak was 12.8±3.0 mL·kg-1·min-1 and VO2peak (% pred.) was 62.1%±14.9%. VO2peak presented a strong positive correlation with FEV1 (% pred.), r: 0.70, and a moderate negative correlation with the CATs, r: -0.54. In the VO2peak estimation model based on the CAT (estimated VO2peak =15.148- 0.185× CATs), the index explained 20% of the variance, with estimated error of 2.826 mL·kg-1·min-1. In the VO2peak estimation model based on FEV1 (estimated VO2peak =6.490+ 0.113× FEV1), the variable explained 50% of the variance, with an estimated error of 2.231 mL·kg-1·min-1. In the VO2peak estimation model based on CATs and FEV1 (estimated VO2peak =8.441- 0.0999× CAT + 0.1000× FEV1), the variables explained 55% of the variance, with an estimated error of 2.156 mL·kg-1·min-1. Conclusion: COPD patients’ maximum aerobic capacity has a significant correlation with easily accessible and widely used clinical variables, such as the CATs and FEV1, which can be used to estimate peak VO2.
Cardiac autonomic modulation (CAM) is impaired in patients with stable COPD. Exacerbation aggravates the patients' health status and functional capacity. While the clinical and functional effects of ...exacerbation are known, no studies investigated CAM during exacerbation and whether there is a relationship between CAM and functional capacity and dyspnea.
Thirty-two patients with moderate to severe COPD were enrolled into two groups: stable COPD (GSta, n=16) and acute exacerbation of COPD (GAE, n=16). The GAE patients were evaluated 24-48 hours after starting standard therapy for COPD exacerbation during hospitalization; the GSta patients were evaluated in an outpatient clinic and included in the study if no decompensation episodes had occurred during the previous month. The heart rate (HR) and R-wave peak detection intervals in ms (RRi) were registered using a heart rate monitor (Polar
system) at rest in seated position during 10 minutes. CAM was assessed by heart rate variability (HRV) linear and non-linear analysis. Functional capacity was evaluated by handgrip strength test, performed by Jamar
dynamometer, and dyspnea was scored using the modified scale of the Medical Research Council.
GAE presented higher parasympathetic CAM values compared with GSta for square root of the mean squared differences of successive RRi (RMSSD; 17.8±5.6 ms vs 11.7±9.5 ms); high frequency (HF; 111.3±74.9 ms
vs 45.6±80.7 ms
) and standard deviation measuring the dispersion of points in the plot perpendicular to the line of identity (SD1; 12.7±3.9 ms vs 8.3±6.7 ms) and higher CAM values for standard deviation of the mean of all of RRi (STD RRi; 19.3±6.5 ms vs 14.3±12.5 ms); RRi tri (5.2±1.7 ms vs 4.0±3.0 ms); triangular interpolation of NN interval histogram (TINN; 88.7±26.9 ms vs 70.6±62.2 ms); low frequency (LF; 203±210.7 ms
vs 101.8±169.7 ms
) and standard deviation measuring the dispersion of points along the line of identity (SD2; 30.4±14.8 ms vs 16.2±12.54 ms). Lower values were observed for the complexity indices: approximate entropy (ApEn; 0.9±0.07 vs 1.06±0.06) and sample entropy (SampEn; 1.4±0.3 vs 1.7±0.3). Significant and moderate associations were observed between HF (nu) and handgrip strength (
=-0.58;
=0.01) and between LF (ms
) and subjective perception of dyspnea (
=-0.53;
=0.03).
COPD exacerbated patients have higher parasympathetic CAM than stable patients. This should be interpreted with caution since vagal influence on the airways determines a narrowing and not a better clinical condition. Additionally, functional capacity was negatively associated with parasympathetic CAM in COPD exacerbation.
The aim of this work was to evaluate the hemodynamic, autonomic, and metabolic responses during resistance and dynamic exercise before and after an 8-week resistance training program using a ...low-intensity (30% of 1 repetitium maximum), high-repetition (3 sets of 20 repetitions) model, added to an aerobic training program, in a coronary artery disease cohort.
Twenty male subjects with coronary artery disease (61.1 ± 4.7 years) were randomly assigned to a combined training group (resistance + aerobic) or aerobic training group (AG). Heart rate, stroke volume, cardiac output, minute ventilation, blood lactate, and parasympathetic modulation indices of heart rate (square root of the mean squared differences of successive RR intervals RMSSD and dispersion of points perpendicular to the line of identity that provides information about the instantaneous beat-to-beat variability SD1) were obtained before and after an 8-week RT program while performing exercise on a cycle ergometer and a 45-degree leg press.
Resistance training resulted in an increase in maximal and submaximal load tolerance (P < 0.01), a decreased hemodynamic response (P < 0.01), and a reduction in blood lactate in the combined training group compared to the aerobic training group during the 45-degree leg press. During exercise on a cycle ergometer, there was a decreased hemodynamic response and increased minute ventilation (P < 0.01). The 8-week RT program resulted in greater parasympathetic tone (RMSSD and SD1) and an increase in the SDNN index during exercise on a cycle ergometer and 45-degree leg press (P < 0.05).
An 8-week resistance training program associated with aerobic training may attenuate hemodynamic stress, and modify metabolic and autonomic responses during resistance exercise. The training program also appeared to elicit beneficial cardiovascular and autonomic effects during exercise.
To evaluate the heart rate variability (HRV) indices and heart rate (HR) responses during isometric contraction (IC) and Valsalva maneuver (VM) in COPD patients.
Twenty-two stable moderate to severe ...COPD patients were evaluated. R-R intervals were recorded (monitor Polar
S810i) during dominant upper limb IC (2 minutes). Stable signals were analyzed by Kubios HRV
software. Indices of HRV were computed in the time domain (mean HR; square root of the mean squared differences of successive RR intervals RMSSD and HRV triangular index RR tri index) and in the frequency domain (high frequency HF; low frequency LF and LF/HF ratio). The HR responses were evaluated at rest, at the peak and at the nadir of the VM (15 seconds). The Valsalva index was also calculated.
During IC: time domain indices (mean HR increased
=0.001, RMSSD, and RR tri index decreased
=0.005 and
=0.005, respectively); frequency domain indices (LF increased
=0.033 and HF decreased
=0.002); associations were found between forced expiratory volume in 1 second (FEV
) vs RMSSD (
=0.04;
=-0.55), FEV
vs HR (
=0.04;
=-0.48), forced vital capacity (FVC) vs RMSSD (
=0.05;
=-0.62), maximum inspiratory pressure (MIP) vs HF (
=0.02;
=0.68). FEV
and FVC justified 30% of mean HR. During VM: HR increased (
=0.01); the nadir showed normal bradycardic response; the Valsalva index was =0.7.
COPD patients responded properly to the upper limb IC and to the VM; however, HR recovery during VM was impaired in these patients. The severity of the disease and MIP were associated with increased parasympathetic modulation and higher chronotropic response.
Chronic obstructive pulmonary disease (COPD) manifests itself in complex ways, with local and systemic effects; because of this, a multifactorial approach is needed for disease evaluation, in order ...to understand its severity and impact on each individual. Thus, our objective was to study the correlation between easily accessible variables, usually available in clinical practice, and maximum aerobic capacity, and to determine models for peak oxygen uptake (VO
peak) estimation in COPD patients.
Individuals with COPD were selected for the study. At the first visit, clinical evaluation was performed. During the second visit, the volunteers were subjected to the cardiopulmonary exercise test. To determine the correlation coefficient of VO
peak with forced expiratory volume in 1 second (FEV
) (% pred.) and the COPD Assessment Test score (CATs), Pearson or Spearman tests were performed. VO
at the peak of the exercise was estimated from the clinical variables by simple and multiple linear regression analyses.
A total of 249 subjects were selected, 27 of whom were included after screening (gender: 21M/5F; age: 65.0±7.3 years; body mass index: 26.6±5.0 kg/m
; FEV
(% pred.): 56.4±15.7, CAT: 12.4±7.4). Mean VO
peak was 12.8±3.0 mL⋅kg
⋅min
and VO
peak (% pred.) was 62.1%±14.9%. VO
peak presented a strong positive correlation with FEV
(% pred.),
: 0.70, and a moderate negative correlation with the CATs,
: -0.54. In the VO
peak estimation model based on the CAT (estimated VO
peak =15.148- 0.185× CATs), the index explained 20% of the variance, with estimated error of 2.826 mL⋅kg
⋅min
. In the VO
peak estimation model based on FEV
(estimated VO
peak =6.490+ 0.113× FEV
), the variable explained 50% of the variance, with an estimated error of 2.231 mL⋅kg
⋅min
. In the VO
peak estimation model based on CATs and FEV
(estimated VO
peak =8.441- 0.0999× CAT + 0.1000× FEV
), the variables explained 55% of the variance, with an estimated error of 2.156 mL⋅kg
⋅min
.
COPD patients' maximum aerobic capacity has a significant correlation with easily accessible and widely used clinical variables, such as the CATs and FEV
, which can be used to estimate peak VO
.
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