Effect of Different Circuit Training on Cardiovascular Responses in Cirrhotic Patients.

The purpose of this study was to analyze and compare heart rate (HR), heart rate variability (HRV), and blood pressure (BP) responses during and after circuit resistance training with 1 min. (CIR1) vs. 2 min. (CIR2) rest intervals between exercises in liver cirrhosis patients. 10 patients (7 women, 3 men) participated in 2 experimental sessions (CIR1 and CIR2) in random order. Each experimental session consisted of 6 exercises performed for 3 sets of 10 repetitions with 70% of the 10-RM load. The only difference between experimental sessions was taking either 1 min. (CIR1) or 2 min. (CIR2) of rest between exercises. Prior and during each session, BP, HR and HRV (beat-to-beat intervals) were assessed. Training efficiency were significant higher for CIR1 when compared to CIR2, since same total training volume was performed in less time. Both protocols elicited significant changes in HR, SBP, and SampEn. Based on the ∆HR and ∆IRR between protocols, higher cardiovascular stress was observed for CIR1 vs. CIR2. However, the patients presented a similar recovery pattern between experimental sessions, and did not present significant alterations in the HRV at 60 min post-workout. In summary, the fast adjustment of autonomic modulation in HRV and BP suggests that circuit resistance training with 1-min or 2-min rest intervals between exercises elicits typical cardiovascular responses in liver cirrhosis patients.

Order Effects of Resistance and Stretching Exercises on Heart Rate Variability and Blood Pressure in Healthy Adults.

da Silva Araujo, G, Behm, DG, Monteiro, ER, de Melo Fiuza, AGF, Gomes, TM, Vianna, JM, Reis, MS, and da Silva Novaes, J. Order effects of resistance and stretching exercises on heart rate variability and blood pressure in healthy adults. J Strength Cond Res 33(10): 2684-2693, 2019-The purpose of this study was to compare the acute effect of different combinations and order of resistance exercise (RE) and stretching exercise (SE) on heart rate variability, systolic blood pressure (SBP), and diastolic blood pressure (DBP). Twenty subjects, recreationally trained, performed 5 sessions in a random order: (a) SE followed by RE no rest (SE + RE), (b) RE followed by SE no rest (RE + SE), (c) SE between RE sets (SBE), (d) SE isolated, and (e) RE isolated. Heart rate variability, SBP, and DBP were collected for 15 minutes before (baseline) and 60 minutes after each experimental session. A significant decrease was found for standardized deviation of differences between adjacent normal r-r intervals (RMSSDms) SE + RE (-50.79%), SE (+9.2%), SBE (-42.8%), and RE (-46.3%). Similarly, a significant increase was found for LFnu in SE + RE (+12.8%) and SBE (+16.6%). In addition, a significant decrease was found for HFnu in SE + RE (-34.8%) and SBE (-39.7%). Finally, a significant decrease was found for SBP in SE (-6.1%). In conclusion, this study indicated that SE followed by RE promotes a reduction in LFnu and RMSSDnu, with trivial to small magnitude decreases in SBP. Therefore, performing SE either before or between RE would be an important exercise prescription recommendation to lower cardiac load and consequently greater safety.

Dysautonomy in different death risk groups (Rassi score) in patients with Chagas heart disease.

BACKGROUND: It has been difficult to prove that "catecholamine-induced cardiomyopathy" contributes to the mechanism of sudden cardiac death in Chagas heart disease. Also, it is almost impossible to rule out the possibility that it is not involved in the process. More importantly, the vagal-cholinergic pathway in the ventricle plays a direct role in the prevention of the initiation of complex ventricular arrhythmias, including nonsustained ventricular tachycardia, ventricular fibrillation responsible for sudden death. OBJECTIVE: To determine frequency of parasympathetic autonomic indices among the different groups of risk of cardiovascular death when stratified by Rassi score. METHODS: Patients with Chagas heart disease were selected and divided into three risk groups by Rassi score. A fourth group, non-Chagas group, was of similar age and gender. All were subjected to analysis of heart rate variability during controlled breathing (RSA) and tilt table passive test (tilt test). High frequency and low frequency/high frequency ratio were calculated and presented by box-plot. Also, t-test was used to compare the two groups. RESULTS: It was observed that the parasympathetic and sympathetic component were affected, when the risk group increased the response was worsened to the stimulus (RSA or Tilt). Also, the low-risk group was jeopardized, when compared to the non-Chagas group. CONCLUSION: The loss of parasympathetic modulation was present in all Rassi risk groups, including the low risk, indicating that a morphological change of the myocardium represents a detectable neurofunctional change.

Incremental Ramp Load Protocol to Assess Inspiratory Muscle Endurance in Healthy Individuals: Comparison with Incremental Step Loading Protocol.

INTRODUCTION: Protocols for obtaíníng the maxímum threshold pressure have been applied wíth límited precision to evaluate ínspiratory muscle endurance. In thís sense, new protocols are needed to allow more relíable measurements. The purpose of the present study was to compare a new incremental ramp load protocol for the evaluation of ínspíratory muscle endurance wíth the most used protocol in healthy indíviduals. METHODS: This was a prospective cross-sectional study carried out ín a síngle center. Nínety-two healthy indíviduals (43 men [22 ± 3 years] and 49 women [22 ± 3 years]) were randomly allocated to perform: (i) íncremental ramp load protocol and (íí) íncremental step loadíng protocol. The sustained pressure threshold (or maximum threshold pressure), maximum threshold pressure/dynamic strength índex ratío, time untíl task faílure, as well as dífference between the mean heart rate of the last five mínutes of baselíne and the peak heart rate of the last 30 seconds of each protocol were measured. RESULTS: Incremental ramp load protocol wíth small íncreases in the load and starting from mínímum values of strength index was able to evaluate the inspiratory muscle endurance through the maxímum threshold pressure of healthy indívíduals. CONCLUSION: The present study suggests that the íncremental ramp load protocol is able to measure maximum threshold pressure in a more thorough way, wíth less progression and greater accuracy in the load stratification compared to the límited incremental step loading protocol and with a safe and expected cardiovascular response in healthy individuals.

Strength training improves functional capacity of individuals with chronic heart failure: Randomized clinical trial.

INTRODUCTION: Chronic heart failure (CHF) is characterized by dyspnea, exercise intolerance and impaired quality of life. Physical exercise is a key point in the treatment of these outcomes. OBJECTIVE: To evaluate the effect of 24 weeks of two different training strategies on functional capacity, muscle strength and quality of life in individuals with CHF. METHODS: The following tests and evaluations were performed before and after 24 weeks of training: exercise test, one-repetition maximum test (1- RM) and Minnesota Living with Heart Failure Questionnaire (MLHFQ). Subjects were randomized according to the modality they would perform first: aerobic training group (ATG - n=6) or strength training group (STG - n=7). RESULTS: The sample consisted of 13 individuals (10 men), aged 55 ± 12 years and a left ventricular ejection fraction (LVEF) of 38.8 ± 5.3%. There was a significant increase in V'O 2peak only in STG (STG: 26.92 ± 9.81 vs 30.52 ± 8.39 mL.kg -1 .min -1 - p=0.025; ATG: 19.60 ± 7,00 vs 22.42 ± 8.54 mL.kg -1 .min -1 - p=0.119). Both groups showed significant improvements in muscle strength (STG: 45 ± 17 vs 51 ± 20 kg - p=0.001; ATG: 38 ± 19 vs 42 ± 20 kg - p=0.012). There was no significant difference in quality of life (STG: 30 ± 18 vs 24 ± 20 - p=0.109; ATG: 36 ± 16 vs 26 ± 15 - p=0.143). CONCLUSION: The early implementation of strength training improves functional capacity and muscle strength of individuals with CHF.

Effect of an exercise-based cardiac rehabilitation program on quality of life of patients with chronic Chagas cardiomyopathy: results from the PEACH randomized clinical trial.

To investigate the effect of an exercise-based cardiac rehabilitation program on the quality of life (QoL) of patients with chronic Chagas cardiomyopathy (CCC). PEACH study was a single-center, superiority randomized clinical trial of exercise training versus no exercise (control). The sample comprised Chagas disease patients with CCC, left ventricular ejection fraction < 45%, without or with HF symptoms (CCC stages B2 or C, respectively). QoL was assessed at baseline, after three months, and at the end of six months of follow-up using the SF-36 questionnaire. Patients randomized for the exercise group (n = 15) performed exercise training (aerobic, strength and stretching exercises) for 60 min, three times a week, during six months. Patients in the control group (n = 15) were not provided with a formal exercise prescription. Both groups received identical nutritional and pharmaceutical counseling during the study. Longitudinal analysis of the effects of exercise training on QoL, considering the interaction term (group × time) to estimate the rate of changes between groups in the outcomes (represented as beta coefficient), was performed using linear mixed models. Models were fitted adjusting for each respective baseline QoL value. There were significant improvements in physical functioning (ß = + 10.7; p = 0.02), role limitations due to physical problems (ß = + 25.0; p = 0.01), and social functioning (ß = + 19.2; p < 0.01) scales during the first three months in the exercise compared to the control group. No significant differences were observed between groups after six months. Exercise-based cardiac rehabilitation provided short-term improvements in the physical and mental aspects of QoL of patients with CCC.Trial registration: ClinicalTrials.gov Identifier: NCT02517632; August 7, 2015.

Association Between Upper Limb Strength Through 1-Repetition Maximum Test and V'O2peak in Heart Failure.

Purpose: This study aimed to evaluate whether there is a correlation between the maximum strength of upper limb when performing a multijoint exercise and peak oxygen uptake (V'O2peak) in Chronic Heart Failure (CHF) subjects. Method: This cross-sectional study involved CHF subjects with a left ventricular ejection fraction (LVEF) less than 50%, who underwent a cardiopulmonary exercise test (CPET) on a treadmill and 1-repetition maximum (1-RM) test for upper limb strength using a bench press exercise. Results: The sample consisted of 16 individuals aged 54 ± 12 years with a LVEF of 37 ± 7%. The V'O2peak was 14.98 ± 5.4 ml·min-1·kg-1 and mean maximum load in the 1-RM test was 38 ± 16 kg. There was strong correlation of V'O2peak with the load in the 1-RM test (r = 0.70; p = .037; r2 = 0.48). Conclusion: There is a strong correlation between the load in 1-RM test for upper limb with V'O2peak in CHF individuals. It is a safe, inexpensive and reproducible way to assess the muscle strength in this population.

Immediate effects of the high-velocity low-amplitude thrust on the heart rate autonomic modulation of judo athletes.

INTRODUCTION: There is controversy about the repercussions of high speed-low amplitude thrust (HVLAT) manipulation in the thoracic region on the autonomic nervous system. OBJECTIVE: To evaluate the immediate effects of the HVLAT in the high thoracic region on the heart rate autonomic modulation of judo athletes. METHODS: In the experimental study, thirty-eight healthy men divided into 2 groups (Judo athletes and non-athletes) having heart rate variability (HRV) collected beat-to-beat using a cardio-pacemater during all stages of the manipulation: i) rest, ii) time 1 (participant positioning), iii) time 2 (positioning of the participant together with the therapist), iv) HVLAT manipulation, v) post 5min, vi) post 10min and vii) post 15min HVLAT. Systolic blood pressure (SBP), diastolic blood pressure (DBP), breath frequency (BF), and HRV were also analyzed. RESULTS: A higher sympathetic modulation was observed with an increase in the standard deviation of successive normal R-R intervals (SDNN) and SD2 indices representing the total variability, however, there was no significant statistical difference in the root mean square of the mean squared differences (RMSSD), percentual of interval differences of successive NN intervals greater than 50 ms (pNN50), and SD1 variables, which represent the parasympathetic nervous system. CONCLUSION: HVLAT manipulation was able to decrease HRV during manipulation, reflecting sympathetic hyperactivity. However, the return of the HRV indices to the baseline conditions in the first minutes of recovery in Judo athletes and non-athletes reflected the safety of the application of the manipulation in these conditions studied.

Limited cardiopulmonary capacity in patients with liver cirrhosis when compared to healthy subjects.

OBJECTIVES: The present study compared cardiorespiratory capacity between cirrhotic patients and healthy subjects. METHODS: Nineteen cirrhotic patients and 19 healthy subjects, paired by age and gender, participated in the study. Volunteers performed an incremental cardiopulmonary test with a ramp protocol, a ventilatory and metabolic variables were obtained and analyzed. The recovery was analyzed by calculating the time needed for 50% of oxygen consumption (VO2) recovery to occur as the median between the peak of the exercise and the end of recovery on the VO2 curve (T1/2). The VE/VCO2 slope were performed by the linear regression of ventilation (VE) and carbon dioxide production (VCO2) data. RESULTS: During resting condition, cirrhotic patients presented significantly higher levels of VO2 compared to healthy subjects. The VE/ VO2 and VE/ VCO2 values were significantly higher in the control group at the anaerobic threshold and at the peak of the test compared to cirrhotic patients. Time under effort was significantly higher for healthy subjects. CONCLUSIONS: Based on these findings, it is possible to conclude that liver cirrhosis can compromise the patients' quality of life, mainly by inducing metabolic alterations which can impair functional capacity and lead to a sedentary lifestyle.

Cardiovascular Physiotherapy on Respiratory Sinus Arrhythmia of Patients Undergoing Coronary Artery Bypass Grafting.

INTRODUCTION: Patients in the postoperative period of coronary artery bypass grafting (CABG) present respiratory and autonomic dysfunctions. In this sense, cardiovascular physiotherapy has been offered as an indispensable differential for the improvement of the prognosis of this population. Heart rate variability is a simple, noninvasive method to analyze autonomic modulation, as well as the accentuation maneuver of respiratory sinus arrhythmia, which demonstrates the parasympathetic autonomic control over the heart. Five patients undergoing cardiac surgery performed a protocol of cardiovascular physiotherapy in the postoperative period and had their data referring to the preoperative period, the 1st and 4th postoperative days analyzed.

Concurrent Validity of the Static and Dynamic Measures of Inspiratory Muscle Strength: Comparison between Maximal Inspiratory Pressure and S-Index.

OBJECTIVE: To verify the concurrent validity between the inspiratory muscle strength (IMS) values obtained in static (maximal inspiratory pressure [MIP]) and dynamic (S-Index) assessments. METHODS: Healthy individuals were submitted to two periods of evaluation: i) MIP, static maneuver to obtain IMS, determined by the Mueller's maneuver from residual volume (RV) until total lung capacity (TLC); ii) and S-Index, inspiration against open airway starting from RV until TLC. Both measures were performed by the same evaluator and the subjects received the same instructions. Isolated maneuvers with differences < 10% were considered as reproducible measures. RESULTS: Data from 45 subjects (21 males) were analyzed and that showed statistical difference between MIP and S-Index values (133.5 ± 33.3 and 125.6 ± 32.2 in cmH2O, respectively), with P=0.014. Linear regression showed r2=0.54 and S-Index prediction formula = 39.8+(0.75×MIP). Pearson's correlation demonstrated a strong and significant association between the measures with r=0.74. The measurements showed good concordance evidenced by the Bland-Altman test. CONCLUSION: S-Index and MIP do not present similar values since they are evaluations of different events of the muscular contraction. However, they have a strong correlation and good agreement, which indicate that both are able to evaluate the IMS of healthy individuals.

Ventilatory and Near-Infrared Spectroscopy Responses Similarly Determine Anaerobic Threshold in Patients With Heart Failure.

PURPOSE: The present study compared the level of agreement of anaerobic threshold (AT) between ventilatory and near-infrared spectroscopy (NIRS) techniques in patients with chronic heart failure (CHF) and healthy subjects. METHODS: Patients with CHF (n = 9) and a control group (CG; n = 14) underwent cardiopulmonary exercise testing on a cycle ergometer until physical exhaustion. Determination of AT was performed visually by (1) ventilatory-expired gas analysis curves and (2) oxyhemoglobin (O2Hb) and deoxyhemoglobin (HHb) curves assessed by NIRS. RESULTS: The CHF group presented significantly lower oxygen consumption (O2), heart rate, and workload at AT when compared with the CG measured by NIRS (P < .05). However, the effect size, measured by the Cohen d, revealed large magnitude (>0.80) in both techniques when compared between CHF patients and the CG. In addition, ventilatory and NIRS techniques demonstrated significant and very strong/strong correlations for relative O2 (r = 0.91) and heart rate (r = 0.85) in the detection of AT in the CHF group. CONCLUSION: Both ventilatory and NIRS assessments are correlated and there are no differences in the responses between CHF patients and healthy subjects in the determination of AT. These findings indicate both approaches may have utility in the assessment of submaximal exercise performance in patients with CHF.

Cardiovascular Acute Effects of Traditional vs. Paired Set Resistance Training in Patients With Liver Cirrhosis.

Purpose: This study compared the acute effects of two different resistance training methods on heart rate variability, blood pressure, and rating of perceived exertion in patients with liver cirrhosis. Methods: Ten patients with Child-Pugh A (seven women and three men) participated in two experimental sessions, in random order: The traditional set condition consisted of three sets of six exercises performed in a sequential manner, while the paired set condition consisted of alternating sets between two exercises (three pairs of exercises). Ten repetitions were performed for each set with 70% of a 10 repetition maximum load and with 2 min rest between sets. Blood pressure and heart rate variability were assessed pre-workout and for 60 min post-workout. The rating of perceived exertion was assessed at the end of the third set for each exercise. Results: Significant alterations in heart rate variability were observed when considering the lowest value obtained during recovery, in which the SDNN was reduced in both the traditional set and paired set conditions, as well as the root mean square of standard deviation for the traditional set condition (p < .05). Additionally, for the paired set condition, there was a significant reduction in the HFnu band and a significant increase in the LFnu band (p < .05). Effect size showed reductions in diastolic and mean blood pressure until 30 min in a small magnitude for traditional sets. Conclusion: Similar cardiovascular responses were observed between methods eliciting normal physiological responses within safe limits for patients with liver cirrhosis.

Incremental Ramp Load Protocol to Assess Inspiratory Muscle Endurance in Healthy Individuals: Comparison with Incremental Step Loading Protocol

ABSTRACT Introduction: Protocols for obtaining the maximum threshold pressure have been applied with limited precision to evaluate inspiratory muscle endurance. In this sense, new protocols are needed to allow more reliable measurements. The purpose of the present study was to compare a new incremental ramp load protocol for the evaluation of inspiratory muscle endurance with the most used protocol in healthy individuals. Methods: This was a prospective cross-sectional study carried out in a single center. Ninety-two healthy individuals (43 men [22 ± 3 years] and 49 women [22 ± 3 years]) were randomly allocated to perform: (i) incremental ramp load protocol and (ii) incremental step loading protocol. The sustained pressure threshold (or maximum threshold pressure), maximum threshold pressure/dynamic strength index ratio, time until task failure, as well as difference between the mean heart rate of the last five minutes of baseline and the peak heart rate of the last 30 seconds of each protocol were measured. Results: Incremental ramp load protocol with small increases in the load and starting from minimum values of strength index was able to evaluate the inspiratory muscle endurance through the maximum threshold pressure of healthy individuals. Conclusion: The present study suggests that the incremental ramp load protocol is able to measure maximum threshold pressure in a more thorough way, with less progression and greater accuracy in the load stratification compared to the limited incremental step loading protocol and with a safe and expected cardiovascular response in healthy individuals.

Oxygen uptake on-kinetics during six-minute walk test predicts short-term outcomes after off-pump coronary artery bypass surgery.

PURPOSE: We aimed to investigate the ability of oxygen uptake kinetics to predict short-term outcomes after off-pump coronary artery bypass grafting. METHODS: Fifty-two patients aged 60.9 ± 7.8 years waiting for off-pump coronary artery bypass surgery were evaluated. The 6-min walk test distance was performed pre-operatively, while simultaneously using a portable cardiopulmonary testing device. The transition of oxygen uptake kinetics from rest to exercise was recorded to calculate oxygen uptake kinetics fitting a monoexponential regression model. Oxygen uptake at steady state, constant time, and mean response time corrected by work rate were analysed. Short-term clinical outcomes were evaluated during the early post-operative of off-pump coronary artery bypass surgery. RESULTS: Multivariate analysis showed body mass index, surgery time, and mean response time corrected by work rate as independent predictors for short-term outcomes. The optimal mean response time corrected by work rate cut-off to estimate short-term clinical outcomes was 1.51 × 10-3 min2/ml. Patients with slower mean response time corrected by work rate demonstrated higher rates of hypertension, diabetes, EuroSCOREII, left ventricular dysfunction, and impaired 6-min walk test parameters. The per cent-predicted distance threshold of 66% in the pre-operative was associated with delayed oxygen uptake kinetics. CONCLUSIONS: Pre-operative oxygen uptake kinetics during 6-min walk test predicts short-term clinical outcomes after off-pump coronary artery bypass surgery. From a clinically applicable perspective, a threshold of 66% of pre-operative predicted 6-min walk test distance indicated slower kinetics, which leads to longer intensive care unit and post-surgery hospital length of stay. Implications for rehabilitation Coronary artery bypass grafting is a treatment aimed to improve expectancy of life and prevent disability due to the disease progression; The use of pre-operative submaximal functional capacity test enabled the identification of patients with high risk of complications, where patients with delayed oxygen uptake kinetics exhibited worse short-term outcomes; Our findings suggest the importance of the rehabilitation in the pre-operative in order to "pre-habilitate" the patients to the surgical procedure; Faster oxygen uptake on-kinetics could be achieved by improving the oxidative capacity of muscles and cardiovascular conditioning through rehabilitation, adding better results following cardiac surgery.

Noninvasive ventilation acutely modifies heart rate variability in chronic obstructive pulmonary disease patients.

OBJECTIVE: The purpose of present study was to evaluate the acute effects of bi-level positive airway pressure (BiPAP) on heart rate variability (HRV) of stable chronic obstructive pulmonary disease patients (COPD). METHODS: Nineteen males with COPD (69+/-8 years and with forced expiratory volume in 1s <50% of predicted) and eight healthy sedentary age-matched (69 years) males in the control group (CG) were evaluated during two conditions of controlled respiratory rate: spontaneous breathing (SB) and BiPAP (inspiratory and expiratory levels between 12-14 cmH(2)O and 4-6 cmH(2)O, respectively). Peripheral oxygen saturation (SpO(2)), end-tidal of carbon dioxide (ETCO(2)), systolic blood pressure (SBP) and R-R interval were obtained. HRV was analyzed by time (RMSSD and SDNN index) and frequency domains (high frequency - HF, low frequency - LF and HF/LF ratio). RESULTS: Significant reduction of ETCO(2) and SBP in both groups and increase of SpO(2) in COPD group was observed during BiPAP ventilation (p<0.05). During spontaneous breathing, patients with COPD presented lower values of LF, LF/HF and higher values of HF when compared to CG (p<0.05). However, HF was significantly reduced and LF increased during BiPAP ventilation (58+/-19-48+/-15 and 41+/-19-52+/-15 un, respectively) in COPD group. Significant correlations between delta BiPAP-SB (Delta) ETCO(2) and DeltaHF were found (r=0.89). CONCLUSIONS: Sympathetic and parasympathetic neural control of heart rate is altered in COPD patients and that BiPAP acutely improves ventilation, enhances sympathetic response and decreases vagal tonus. The improvement of ventilation caused by BiPAP was associated with reduced cardiac vagal activity in stable moderate-to-severe COPD patients.

Association of Oscillatory Ventilation during Cardiopulmonary Test to Clinical and Functional Variables of Chronic Heart Failure Patients.

OBJECTIVE: The aim of this study is to characterize the presence of exercise oscillatory ventilation (EOV) and to relate it with other cardiopulmonary exercise test (CET) responses and clinical variables. METHODS: Forty-six male patients (age: 53.1±13.6 years old; left ventricular ejection fraction [LVEF]: 30±8%) with heart failure were recruited to perform a maximal CET and to correlate the CET responses with clinical variables. The EOV was obtained according to Leite et al. criteria and VE/VCO2 > 34 and peak VO2 < 14 ml/kg/min were used to assess patients' severity. RESULTS: The EOV was observed in 16 of 24 patients who performed the CET, as well as VE/VCO2 > 34 and peak VO2 < 14 ml/kg/min in 14 and 10 patients, respectively. There was no difference in clinical and CET variables of the patients who presented EOV in CET when compared to non-EOV patients. Also, there was no difference in CET and clinical variables when comparing patients who presented EOV and had a VE/VCO2 slope > 34 to patients who just had one of these responses either. CONCLUSION: The present study showed that there was an incidence of patients with EOV and lower peak VO2 and higher VE/VCO2 slope values, but they showed no difference on other prognostic variables. As well, there was no influence of the presence of EOV on other parameters of CET in this population, suggesting that this variable may be an independent marker of worst prognosis in HF patients.

Effects of an intradialytic cardiovascular rehabilitation program on functional capacity and cardiac function: ICRP trial

Abstract Introduction: Chronic kidney disease (CKD) is a worldwide public health problem associated with an increased risk of death from cardiovascular complications. Although previous studies have described significant improvements in exercise in functional capacity and quality of life in patients with end-stage kidney disease (ESKD), there is a lack of studies that propose to assess its impact on cardiac function using transthoracic echocardiogram (ECHO). In addition, most of the intradialytic exercise protocols are inconsistent, and incomplete regarding their intensity prescription, time of intervention, and monitoring. Methods: The present study aims to evaluate the effects of an intradialytic cardiovascular rehabilitation protocol (ICRP) using medium intensity aerobic exercises, for 30 min. on cardiac function and functional capacity. In this 6-month longitudinal study, heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure, peripheral oxygen saturation (SpO2) and modified Borg scale will be analyzed in all HD sessions. The cardiac function will be evaluated by left ventricular ejection fraction (LVEF) through ECHO; functional capacity by the six-minute walk test (6MWT); quality of life through the SF-36 questionnaire and routine laboratory tests and KT/Vsp calculation before and after the ICRP. Conclusion: ICRP protocol will be examined and is expected to improve cardiac function, functional capacity, and quality of life in ESKD patients on hemodialysis.

Additional value of anaerobic threshold in a general mortality prediction model in a urban patient cohort with Chagas cardiomyopathy. / Valor adicional do limiar anaeróbio em um modelo de predição de morte geral em uma coorte urbana de pacientes com cardiopatia chagásica.

BACKGROUND: Anaerobic threshold (AT) is recognized as objective and direct measurement that reflects variations in metabolism of skeletal muscles during exercise. Its prognostic value in heart diseases of non-chagasic etiology is well established. However, the assessment of risk of death in Chagas heart disease is relatively well established by Rassi score. But, the added value that AT can bring to Rassi score has not been studied yet. OBJECTIVES: To assess whether AT presents additional effect to Rassi score in patients with chronic Chagas' heart disease. METHODS: Prospective research of dynamic cohort by review of 150 medical records of patients. Were selected for cohort 45 medical records of patients who underwent cardiopulmonary exercise testing between 1996-1997 and followed until September 2015. Data analysis to detect association between studied variables can be seen using a logistic regression model. The suitability of the models was verified using ROC curves and the coefficient of determination R2. RESULTS: 8 patients (17.78%) died by September 2015, with 7 of them (87.5%) from cardiovascular causes, of which 4 (57.14%) were considered on high risk by Rassi score. With Rassi score as independent variable, and death being the outcome, we obtained an area under the curve (AUC)=0.711, with R2=0.214. Instituting AT as independent variable, we found AUC=0.706, with R2=0.078. When we define Rassi score and AT as independent variables, it was obtained AUC=0.800 and R2=0.263. CONCLUSION: when AT is included in logistic regression, it increases by 5% the explanation (R2) to the death estimation.

Avaliação da modulação autonômica da frequência cardíaca de pacientes com doença renal crônica em hemodiálise: estudo preliminar / Evaluación de la modulación autónoma de la frecuencia cardíaca en pacientes con enfermedad renal crónica sometidos a hemodiálisis: estudio preliminar / Evaluation of the autonomic heart rate modulation of patients with chronic renal disease in hemodyalysis: preliminare study

RESUMO A doença renal crônica (DRC) é definida como dano à função renal. Doentes renais crônicos atingem alta prevalência de morte por eventos cardiovasculares antes dos estágios finais, sendo maior a mortalidade em estágio dialítico, em que é evidenciado um desequilíbrio autonômico. Objetivamos avaliar a modulação simpatovagal de pacientes com DRC em tratamento de hemodiálise ambulatorial. Foram avaliados 23 pacientes, divididos em: Grupo DRC com DRC no estágio 5D (DRC-5D) em tratamento regular de hemodiálise ambulatorial; Grupo-controle com indivíduos saudáveis. A variabilidade da frequência cardíaca (VFC) foi coletada por um cardiofrequencímetro e analisada por índices lineares do domínio do tempo e do domínio da frequência. 14 pacientes no Grupo DRC com média de idade 48±16; e 9 pacientes saudáveis no Grupo-controle com média de idade 64±5. Nos resultados pelo domínio de tempo, o Grupo DRC mostrou valores significativamente maiores da frequência cardíaca (FC) comparado ao Grupo-controle (83,49±13,09 bpm vs. 67,88±9,43 bpm). Todavia, os índices média dos intervalos R-R (735,82±121,54 ms vs. 898,94±123,58 ms), RMSSD (11,75±11,86 ms vs. 20,03±6,80 ms), SDNN (17,06±9,81ms vs. 28,42±7,62 ms) do Grupo DRC mostraram valores significativamente menores comparados aos do Grupo-controle, respectivamente. Nos resultados pelo domínio da frequência, o Grupo DRC mostrou valores significativamente menores em comparação ao Grupo-controle nos índices BFab (129,7±184,3 ms vs. 262,31±168,15 ms) e AFab (82,70±227,66 ms vs. 180,77±119,85 ms). Pacientes com DRC em hemodiálise apresentaram redução da modulação parassimpática quando comparados com indivíduos saudáveis, sugerindo prejuízo do balanço simpatovagal e, consequente, disfunção autonômica cardíaca.

RESUMEN La enfermedad renal crónica (ERC) se define como la pérdida de la función renal. Los pacientes renales crónicos tienen una alta prevalencia de muerte por eventos cardiovasculares antes de la etapa final, con mayor mortalidad en la etapa de diálisis, en la que se evidencia un desequilibrio autonómico. Este estudio tuvo como objetivo evaluar la modulación simpatovagal de pacientes con ERC sometidos a tratamiento de hemodiálisis ambulatoria. Se evaluaron 23 pacientes, lo cuales fueron divididos en: Grupo ERC con ERC en etapa 5D (ERC-5D) en tratamiento de hemodiálisis ambulatoria regular; Grupo de control con individuos sanos. Para identificar la variabilidad de la frecuencia cardíaca (VFC) se utilizó un monitor de frecuencia cardíaca y los datos obtenidos fueron analizados por los índices lineales de tiempo y de dominio de frecuencia. En el grupo ERC 14 pacientes tenían un promedio de edad de 48±16 años; y en el grupo control 9 pacientes sanos tenían un promedio de edad de 64±5. En los resultados para el dominio del tiempo, el grupo ERC mostró valores significativamente más altos de frecuencia cardíaca (FC) en comparación con el grupo control (83,49±13,09 lpm vs. 67,88±9,43 lpm). Sin embargo, los índices medios de los intervalos R-R (735,82±121,54 ms vs. 898,94±123,58 ms), RMSSD (11,75±11,86 ms vs. 20,03±6,80 ms), SDNN (17,06±9,81 ms vs. 28,42±7,62 ms) del grupo ERC demostraron valores significativamente más bajos en comparación con el grupo control, respectivamente. En los resultados para el dominio de la frecuencia, en el grupo ERC se obtuvo valores significativamente más bajos en comparación con el grupo control en los índices BFab (129,7±184,3 ms vs. 262,31±168,15 ms) y AFab (82,70±227,66 ms vs. 180,77±119,85 ms). Los pacientes con ERC sometidos a hemodiálisis mostraron una modulación parasimpática reducida en comparación con los individuos sanos, lo que sugiere un deterioro del equilibrio simpaticovagal y, en consecuencia, una disfunción autonómica cardíaca.

ABSTRACT Chronic kidney disease (CKD) is defined as damage to kidney function. Patients have high prevalence of death by cardiovascular events before the final stages of the disease, with higher mortality in dialytic stage, in which autonomic imbalance is evidenced. This study seeks to evaluate sympathovagal modulation of patients with CKD undergoing hemodialysis treatment. We evaluated 23 subjects, divided into: CDK-group with CKD-stage 5D in regular hemodialysis treatment; and Control-group with healthy individuals. Heart rate variability (HRV) was collected by a heart rate monitor and analyzed by linear time domain and frequency domain indices. CDK-group had 14 patients, mean age of 48±16; and Control-group had 9 healthy patients, mean age of 64±5. In the time domain, CDK-group showed significantly higher heart rate values compared with Control-group (83.49±13.09 bpm vs. 67.88±9.43 bpm). However, the mean indices of the R-R intervals (735.82±121.54 ms vs. 898.94±123.58 ms), RMSSD (11.75±11.86 ms vs. 20.03±6.80 ms), and SDNN (17.06±9.81 ms vs. 28.42±7.62 ms) from CDK-group showed significantly lower values compared with Control-group. In frequency domain results, CDK-group showed significantly lower values compared with Control-group in LFab (129.7±184.3 ms vs. 262.31±168.15 ms) and HFab (82.70±227.66 ms vs. 180.77±119.85 ms). Patients with CKD on hemodialysis had reduced parasympathetic modulation compared with healthy subjects, suggesting impairment of the sympathovagal balance and, consequently, cardiac autonomic dysfunction.