Effects of slow and regular breathing exercise on cardiopulmonary coupling and blood pressure

Investigation of the interaction between cardiovascular variables and respiration provides a quantitative and noninvasive approach to assess the autonomic control of cardiovascular function. The aim of this paper is to investigate the changes of cardiopulmonary coupling (CPC), blood pressure (BP) and pulse transit time (PTT) during a stepwise-paced breathing (SPB) procedure (spontaneous breathing followed by paced breathing at 14, 12.5, 11, 9.5, 8 and 7 breaths per minute, 3 min each) and gain insights into the characteristics of slow breathing exercises. RR interval, respiration, BP and PTT are collected during the SPB procedure (48 healthy subjects, 27 ± 6 years). CPC is assessed through investigating both the phase and amplitude dynamics between the respiration-induced components from RR interval and respiration by the approach of ensemble empirical mode decomposition. It was found that even though the phase synchronization and amplitude oscillation of CPC were both enhanced by the SPB procedure, phase coupling does not increase monotonically along with the amplitude oscillation during the whole procedure. Meanwhile, BP was reduced significantly by the SPB procedure (SBP: from 122.0 ± 13.4 to 114.2 ± 14.9 mmHg, p < 0.001, DBP: from 82.2 ± 8.6 to 77.0 ± 9.8 mmHg, p < 0.001, PTT: from 172.8 ± 20.1 to 176.8 ± 19.2 ms, p < 0.001). Our results demonstrate that the SPB procedure can reduce BP and lengthen PTT significantly. Compared with amplitude dynamics, phase dynamics is a different marker for CPC analysis in reflecting cardiorespiratory coherence during slow breathing exercise. Our study provides a methodology to practice slow breathing exercise, including the setting of target breathing rate, change of CPC and the importance of regular breathing. The applications and usability of the study results have also been discussed.National Natural Science Foundation (China) (Grant Number: 61471398)Beijing Natural Science Foundation (Grant Number: 3122034)General Logistics Science Foundation (Grant Number: CWS11C108)National Key Technology Research and Development Program (Grant Numbers: 2013BAI03B04, 2013BAI03B05

Modulations of Heart Rate, ECG, and Cardio-Respiratory Coupling Observed in Polysomnography

The cardiac component of cardio-respiratory polysomnography is covered by ECG and heart rate recordings. However their evaluation is often underrepresented in summarizing reports. As complements to EEG, EOG, and EMG, these signals provide diagnostic information for autonomic nervous activity during sleep. This review presents major methodological developments in sleep research regarding heart rate, ECG and cardio-respiratory couplings in a chronological (historical) sequence. It presents physiological and pathophysiological insights related to sleep medicine obtained by new technical developments. Recorded nocturnal ECG facilitates conventional heart rate variability analysis, studies of cyclical variations of heart rate, and analysis of ECG waveform. In healthy adults, the autonomous nervous system is regulated in totally different ways during wakefulness, slow-wave sleep, and REM sleep. Analysis of beat-to-beat heart-rate variations with statistical methods enables us to estimate sleep stages based on the differences in autonomic nervous system regulation. Furthermore, up to some degree, it is possible to track transitions from wakefulness to sleep by analysis of heart-rate variations. ECG and heart rate analysis allow assessment of selected sleep disorders as well. Sleep disordered breathing can be detected reliably by studying cyclical variation of heart rate combined with respiration-modulated changes in ECG morphology (amplitude of R wave and T wave)

Sildenafil improves microvascular O-2 delivery-to-utilization matching and accelerates exercise O-2 uptake kinetics in chronic heart failure

Sperandio PA, Oliveira MF, Rodrigues MK, Berton DC, Treptow E, Nery LE, Almeida DR, Neder JA. Sildenafil improves microvascular O-2 delivery-to-utilization matching and accelerates exercise O-2 uptake kinetics in chronic heart failure. Am J Physiol Heart Circ Physiol 303: H1474-H1480, 2012. First published September 28, 2012; doi:10.1152/ajpheart.00435.2012.-Nitric oxide (NO) can temporally and spatially match microvascular oxygen (O-2) delivery (QO(2mv)) to O-2 uptake (VO2) in the skeletal muscle, a crucial adjustment-to-exercise tolerance that is impaired in chronic heart failure (CHF). To investigate the effects of NO bioavailability induced by sildenafil intake on muscle QO(2mv)-to-O-2 utilization matching and VO2 kinetics, 10 males with CHF (ejection fraction = 27 +/- 6%) undertook constant work-rate exercise (70-80% peak). Breath-by-breath VO2, fractional O-2 extraction in the vastus lateralis {similar to deoxy-genated hemoglobin + myoglobin ([deoxy-Hb + Mb]) by near-infrared spectroscopy}, and cardiac output (CO) were evaluated after sildenafil (50 mg) or placebo. Sildenafil increased exercise tolerance compared with placebo by similar to 20%, an effect that was related to faster on-and off-exercise VO2 kinetics (P 0.05). On-exercise [deoxy-Hb + Mb] kinetics were slowed by sildenafil (similar to 25%), and a subsequent response overshoot (n = 8) was significantly lessened or even abolished. in contrast, [deoxy-Hb + Mb] recovery was faster with sildenafil (similar to 15%). Improvements in muscle oxygenation with sildenafil were related to faster on-exercise VO2 kinetics, blunted oscillations in ventilation (n = 9), and greater exercise capacity (P < 0.05). Sildenafil intake enhanced intramuscular QO(2mv)-to-VO2 matching with beneficial effects on VO2 kinetics and exercise tolerance in CHF. the lack of effect on CO suggests that improvement in blood flow to and within skeletal muscles underlies these effects.Universidade Federal de São Paulo, Dept Med, Div Resp Dis, Pulm Funct & Clin Exercise Physiol Unit, BR-04020050 São Paulo, BrazilQueens Univ, Dept Med, Div Resp & Crit Care Med, Kingston, ON K7L 3N6, CanadaUniversidade Federal de São Paulo, Dept Med, Div Cardiol, BR-04020050 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Resp Dis, Pulm Funct & Clin Exercise Physiol Unit, BR-04020050 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Cardiol, BR-04020050 São Paulo, BrazilWeb of Scienc

Development and assessment of methods for arm-cranking exercise assisted by functional electrical stimulation (FES) in tetraplegia

In this pilot study, a new avenue for exercise in tetraplegia, involving FES applied to upper limb muscles, is suggested. The main motivation for developing methods for FES-assisted arm-cranking exercise is to provide an exercise modality specifically designed for tetraplegia that might address cardiopulmonary issues, as well as work with remaining voluntary control of upper body musculature. One primary aim of this thesis was to determine the feasibility of using these systems in tetraplegia. To investigate this, standard protocols for exercise training, and incremental and constant-load exercise testing, were adapted to make them suitable for this population and this exercise modality. These novel protocols are described here, and represent one of the contributions of the thesis. The implementation of these protocols for an experimental evaluation of the proposed systems for FES-assisted arm-cranking exercise makes up the main part of the thesis. Five volunteers with tetraplegia participated in this experimental evaluation, and their data are presented as two main case studies, and additional case reports. The first outcome of thesis evaluation is that it shows the feasibility of the proposed methods for FES-assisted arm-cranking exercise training and testing in tetraplegia. Secondly, benefits of regular use of the systems are illustrated for some individuals with tetraplegia, based on key indicators of cardiopulmonary fitness and measures of upper limb strength. Thirdly, the limitations of the current set-up for FES-assisted arm-cranking exercise in higher level tetraplegia are identified. In summary, this thesis describes new systems and protocols for FES-assisted arm-cranking exercise in tetraplegia, and provides a preliminary assessment of these methods

Amyotrophic lateral sclerosis : exercise and disease progression

Amyotrophic Lateral Sclerosis (ALS) belongs to a group of neurological disorders known as motor neuron diseases, which are caused by gradual degeneration and consequent death of motor neurons. In general, the disease begins in one of two fundamental ways: with involvement of the muscles of the bulbar region; or with loss of muscle strength of the upper or lower limbs - spinal form. Although other rare forms of manifestation are also cited in the literature, such as: respiratory (when respiratory muscles are initially affected); axial (initially affecting the cervical and paraspinal muscles) and the diffuse form (generalized onset of the disease). These forms of presentation determine the initial symptoms. Patients may initially develop muscle weakness in the limbs resulting in various clinical conditions with paresis, speech problems with dysarthria, dysphagia, and respiratory symptoms with dyspnea, and evolve to complete loss of body movements control. The degree of functional disability and dependence resulting from ALS lead the patient to gradually needing a caregiver for all their activities of daily life. The mean survival for ALS is around 3 - 5 years from first symptoms, and the fatal event usually occurs due to respiratory failure or infection. Although there is no effective treatment to halt disease progression, the clinical management has evolved positively in last years. The technological advance of medical interventions has contributed to a longer survival and higher quality of life. The monitoring of non-invasive ventilation has been very helpful for the clinical follow up and to decrease the anxiety experienced by caregivers. Unfortunately, the aerobic exercise is not a usual therapeutic option for ALS patients in the clinical management yet. Physical exercise has been suggested to promote growth factor delivery in experimental animal models of ALS. However, the aerobic exercise is understudied in ALS patients due the suspicious that the exercise could be harmful for this population. Meeting the recommendations from the last Cochrane review about Therapeutic exercise in ALS, we have analyzed the impact of aerobic exercise in the ALS progression. This thesis has 2 main contributions: 1 - To study the efficacy of moderated and accurate defined exercise program on the evolution and survival of ALS, and, 2 - to assess the feasibility to performing exercise monitored remotely from home in ALS patients. In addition, this thesis includes results from additional contributions, which are related to relevant issues always present during disease progression such as management of the respiratory failure (sub-chapters 5.2 and 5.3), the support for ALS caregivers (Chapter 6), and the potential impact of clinical management on disease progression in an environment with lack of resources (Chapter 7). In the sub-chapter 5.2 we present a work which describe the lack of consensus for the ideal timing to start NIV and about the use of alternative respiratory support. We address the impact of NIV and tracheostomy on family and / or informal caregivers, especially how it can affect quality of life. The importance of assessing the emotional, physical, social and psychological capacity of the caregiver is reinforced in order to cope with the increasing care needs of these patients. The sub-chapter 5.3 presents results on the importance of a careful management in the use and configuration of Non-Invasive Ventilation (NIV) parameters, in particular the role of ventilation and adherence adjustments in functional decline and survival of ventilated patients. A wide range of data recorded from the software used in ventilators, nocturnal pulse oximetry measurements and respiratory function tests were analyzed. Our results suggest that the variables that affect the respiratory comfort of the patient are relevant for adherence to NIV and positively affect survival in ALS. The Chapter 6 presents results of a feasibility study about a training program for caregivers. The uncertain progression of the disease and long-term care, as well as the insufficient number of skilled health professionals, determine that the admission of these patients to hospitals or to continuing care units is a complex option. Initiatives that allow better management of the disease at home can be an alternative solution. The functional disability of patients can promote significant financial constraints, and exposes their families to high levels of stress, which can compromise the provision of adequate health care, leading to the hospitalization of these patients. In this project, we identified an excellent level of participation as well as a good result in the evaluation of learning (above 70%). The main limiting factor for participation in the training program was the absence of a secondary caregiver. The Chapter 7 describes results from2 studies conducted with ALS patients in the African continent, which present data on disease progression in an environment with limited resources for clinical management. The Chapter 8 present a general discussion and conclusion of all works included in this Thesis. All the papers presented in this thesis aim to contribute to a broader view of the clinical management of ALS, where the role of exercise associated with more careful respiratory support, and the presence of a well-informed and trained caregiver, can together be an important contribution for the survival and quality of life of the patient with ALS. We hope our work presented in this thesis may contribute to a wider understanding on the clinical management of ALS. In particular demonstrating that controlled exercise associated with careful respiratory support, and the presence of a well-informed and trained caregiver, may be an added value in the survival and quality of life for ALS patient

Participant's Experience with Biofeedback: A Phenomenological Study

This research was used to identify participants’ perceptions towards biofeedback on their physical health prior to, during, and after biofeedback participation. Understanding the ability of biofeedback to treat HTN is very important. It is also crucial to know what participant’s thoughts and feelings are towards biofeedback therapy in order to understand the psychological and emotional elements that participants experience during their participation. In this phenomenological qualitative study, nine participants of paced breathing biofeedback exercises were interviewed to discuss how their thoughts and feelings towards biofeedback were impacted throughout the course of their participation. Participants were between the age of 18 and 35 with a family history of CVD

Slow 0.1 Hz Breathing and Body Posture Induced Perturbations of RRI and Respiratory Signal Complexity and Cardiorespiratory Coupling

Objective: We explored the physiological background of the non-linear operating mode of cardiorespiratory oscillators as the fundamental question of cardiorespiratory homeodynamics and as a prerequisite for the understanding of neurocardiovascular diseases. We investigated 20 healthy human subjects for changes using electrocardiac RR interval (RRI) and respiratory signal (Resp) Detrended Fluctuation Analysis (DFA, α1RRI, α2RRI, α1Resp, α2Resp), Multiple Scaling Entropy (MSERRI1−4, MSERRI5−10, MSEResp1−4, MSEResp5−10), spectral coherence (CohRRI−Resp), cross DFA (ρ1 and ρ2) and cross MSE (XMSE1−4 and XMSE5−10) indices in four physiological conditions: supine with spontaneous breathing, standing with spontaneous breathing, supine with 0.1 Hz breathing and standing with 0.1 Hz breathing. Main results: Standing is primarily characterized by the change of RRI parameters, insensitivity to change with respiratory parameters, decrease of CohRRI−Resp and insensitivity to change of in ρ1, ρ2, XMSE1−4, and XMSE5−10. Slow breathing in supine position was characterized by the change of the linear and non-linear parameters of both signals, reflecting the dominant vagal RRI modulation and the impact of slow 0.1 Hz breathing on Resp parameters. CohRRI−Resp did not change with respect to supine position, while ρ1 increased. Slow breathing in standing reflected the qualitatively specific state of autonomic regulation with striking impact on both cardiac and respiratory parameters, with specific patterns of cardiorespiratory coupling. Significance: Our results show that cardiac and respiratory short term and long term complexity parameters have different, state dependent patterns. Sympathovagal non-linear interactions are dependent on the pattern of their activation, having different scaling properties when individually activated with respect to the state of their joint activation. All investigated states induced a change of α1 vs. α2 relationship, which can be accurately expressed by the proposed measure—inter-fractal angle θ. Short scale (α1 vs. MSE1−4) and long scale (α2 vs. MSE5−10) complexity measures had reciprocal interrelation in standing with 0.1 Hz breathing, with specific cardiorespiratory coupling pattern (ρ1 vs. XMSE1−4). These results support the hypothesis of hierarchical organization of cardiorespiratory complexity mechanisms and their recruitment in ascendant manner with respect to the increase of behavioral challenge complexity. Specific and comprehensive cardiorespiratory regulation in standing with 0.1 Hz breathing suggests this state as the potentially most beneficial maneuver for cardiorespiratory conditioning. © Copyright © 2020 Matić, Platiša, Kalauzi and Bojić