Six-minute walk test and heart rate variability: lack of association in advanced stages of heart failure

1997 ◽  
Vol 6 (5) ◽  
pp. 348-354 ◽  
Author(s):  
MA Woo ◽  
DK Moser ◽  
LW Stevenson ◽  
WG Stevenson

BACKGROUND: The 6-minute walk and heart rate variability have been used to assess mortality risk in patients with heart failure, but their relationship to each other and their usefulness for predicting mortality at 1 year are unknown. OBJECTIVE: To assess the relationships between the 6-minute walk test, heart rate variability, and 1-year mortality. METHOD: A sample of 113 patients in advanced stages of heart failure (New York Heart Association Functional Class III-IV, left ventricular ejection < 0.25) were studied. All 6-minute walks took place in an enclosed, level, measured corridor and were supervised by the same nurse. Heart rate variability was measured by using (1) a standard-deviation method and (2) Poincare plots. Data on RR intervals obtained by using 24-hour Holter monitoring were analyzed. Survival was determined at 1 year after the Holter recording. RESULTS: The results showed no significant associations between the results of the 6-minute walk and the two measures of heart rate variability. The results of the walk were related to 1-year mortality but not to the risk of sudden death. Both measures of heart rate variability had significant associations with 1-year mortality and with sudden death. However, only heart rate variability measured by using Poincare plots was a predictor of total mortality and risk of sudden death, independent of left ventricular ejection fraction, serum levels of sodium, results of the 6-minute walk test, and the standard-deviation measure of heart rate variability. CONCLUSIONS: Results of the 6-minute walk have poor association with mortality and the two measures of heart rate variability in patients with advanced-stage heart failure and a low ejection fraction. Further studies are needed to determine the optimal clinical usefulness of the 6-minute walk and heart rate variability in patients with advanced-stage heart failure.

2010 ◽  
Vol 13 (1) ◽  
pp. 31 ◽  
Author(s):  
Federico Benetti ◽  
Ernesto Pe�herrera ◽  
Teodoro Maldonado ◽  
Yan Duarte Vera ◽  
Valvanur Subramanian ◽  
...  

Background: End-stage heart failure (HF) is refractory to current standard medical therapy, and the number of donor hearts is insufficient to meet the demand for transplantation. Recent studies suggest autologous stem cell therapy may regenerate cardiomyocytes, stimulate neovascularization, and improve cardiac function and clinical status. Although human fetal-derived stem cells (HFDSCs) have been studied for the treatment of a variety of conditions, no clinical studies have been reported to date on their use in treating HF. We sought to determine the efficacy and safety of HFDSC treatment in HF patients.Methods and Results: Direct myocardial transplantation of HFDSCs by open-chest surgical procedure was performed in 10 patients with HF due to nonischemic, nonchagasic dilated cardiomyopathy. Before and after the procedure, and with no changes in their preoperative doses of medications (digoxin, furosemide, spironolactone, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, betablockers), patients were assessed for New York Heart Association (NYHA) class, performance in the exercise tolerance test (ETT), ejection fraction (EF), left ventricular end-diastolic dimension (LVEDD) via transthoracic echocardiography, performance in the 6-minute walk test, and performance in the Minnesota congestive HF test. All 10 patients survived the operation. One patient had a stroke 3 days after the procedure, and although she later recovered, she was unable to perform the follow-up tests. Another male patient experienced pericardial effusion 3 weeks after the procedure. Although it resolved spontaneously, the patient abandoned his control tests and died 5 months after the procedure. An autopsy of the myocardium suggested that new young cells were present in the cardiomyocyte mix. At 40 months, the mean (SD) NYHA class decreased from 3.4 0.5 to 1.33 0.5 (P = .001); the mean EF increased 31%, from 26.6% 4% to 34.8% 7.2% (P = .005); and the mean ETT increased 291.3%, from 4.25 minutes to 16.63 minutes (128.9% increase in metabolic equivalents, from 2.46 to 5.63) (P < .0001); the mean LVEDD decreased 15%, from 6.85 0.6 cm to 5.80 0.58 cm (P < .001); mean performance in the 6-minute walk test increased by 43.2%, from 251 113.1 seconds to 360 0 seconds (P = .01); the mean distance increased 64.4%, from 284.4 144.9 m to 468.2 89.8 m (P = .004); and the mean result in the Minnesota test decreased from 71 27.3 to 6 5.9 (P < .001).Conclusion: Although these initial findings suggest direct myocardial implantation of HFDSCs is feasible and improves cardiac function in HF patients at 40 months, more clinical research is required to confirm these observations.


2020 ◽  
Vol 28 (3) ◽  
pp. 290-299
Author(s):  
Kira A. Ageeva ◽  
Evgenii V. Filippov

Aim. To study the prognostic value of the results of dynamic capnography in the complex assessment of parameters of the respiratory system in 6-minute walk test in patients with chronic heart failure (CHF). Materials and Methods. 73 Patients were examined: the group of study included 48 patients with IIA or IIB stage CHF (mean age 57.94.6 years, 23 men), the control group included 25 practically healthy volunteers (mean age 47.63.5 years, 9 men). The patients were conducted complex determination of parameters of the respiratory system: clinical scaling before and after 6-minute walk test (6MWT), instrumental examinations including spirometry, capnography and pulse oximetry before, during and after physical activity. The analysis of survival was conducted on the basis of the dynamic follow-up of patients within 5 years (60 months). Results. In the analysis of parameters of dyspnea at rest, all the parameters were higher in the group of patients with CHF (р0.05). The distance walked by the patients with CHF in 6 minutes was 488.2390.84 m, which was significantly less than in the control group (815.6053.89 m, р=0.009). Dyspnea as the cause of stoppage/slowing down of walking in 6MWT, was also more often recorded in patients with CHF (93.83.0% and 48.05.1%, р=0.049). Besides, in 6MWT the patients noted: weakness in legs (50.15.0% in the group of CHF and 40.05.0% in the control group, р=0.014), palpitation (29.04.6% and 20.04.1%, respectively, р=0.004). Worsening of dyspnea parameters in 6MWT was more evident in patients with CHF than in the control group (р0.01). In the CHF group, hypocapnic type of ventilation was revealed in 6MWT, analysis of РЕТСО2 trend graphs revealed a wave-like increase in the parameters, the so called periodic breathing (PB). CO2 trend was recorded in CHF group in 58.31.0% of cases (the difference with the control group with р=0.046), the trend of heart rate in 18.80.3% of cases (р=0.027). Cox proportional hazards regression analysis of mortality in patients with CHF showed a prognostic significance of a complex model comprising the following parameters of a patient: body mass index (р=0.005), left ventricular end-diastolic dimension (р=0.034), left ventricular end-systolic dimension (р=0.002), left ventricular ejection fraction (р=0.041), 6MWT distance (р=0.004), desaturation (р=0.009), and the presence of signs of PB during 6MWT (р=0.005). Model coefficients were statistically significant at р0.0001. Conclusions. Dynamic capnography and pulse oximetry allow to identify signs of PB in patients with CHF during 6MWT which may deepen a complex assessment of parameters of the cardio-respiratory system in patients with CHF in order to determine tolerance to physical exercise as well as the effectiveness of the conducted treatment. Complex assessment of survival of patients with CHF showed prognostic significance of the following parameters of a patient: body mass index, left ventricular end-diastolic dimension, left ventricular end-systolic dimension, left ventricular ejection fraction, 6MWT distance, desaturation, PB during 6MWT.


2005 ◽  
Vol 289 (4) ◽  
pp. H1729-H1735 ◽  
Author(s):  
Sophie Motte ◽  
Myrielle Mathieu ◽  
Serge Brimioulle ◽  
Anne Pensis ◽  
Lynn Ray ◽  
...  

Heart failure is associated with autonomic imbalance, and this can be evaluated by a spectral analysis of heart rate variability. However, the time course of low-frequency (LF) and high-frequency (HF) heart rate variability changes, and their functional correlates during progression of the disease are not exactly known. Progressive heart failure was induced in 16 beagle dogs over a 7-wk period by rapid ventricular pacing. Spectral analysis of heart rate variability and respiration, echocardiography, hemodynamic measurements, plasma atrial natriuretic factor, and norepinephrine was obtained at baseline and every week, 30 min after pacing interruption. Progressive heart failure increased heart rate (from 91 ± 4 to 136 ± 5 beats/min; P < 0.001) and decreased absolute and normalized (percentage of total power) HF variability from week 1 and 2, respectively ( P < 0.01). Absolute LF variability did not change during the study until it disappeared in two dogs at week 7 ( P < 0.05). Normalized LF variability increased in moderate heart failure ( P < 0.01), leading to an increased LF-to-HF ratio ( P < 0.05), but decreased in severe heart failure ( P < 0.044; week 7 vs. week 5). Stepwise regression analysis revealed that among heart rate variables, absolute HF variability was closely associated with wedge pressure, right atrial and pulmonary arterial pressure, left ventricular ejection fraction and volume, ratio of maximal velocity of early (E) and atrial (A) mitral flow waves, left atrial diameter, plasma norepinephrine, and atrial natriuretic peptide (0.45 < r < 0.65, all P < 0.001). In tachycardia-induced heart failure, absolute HF heart rate variability is a more reliable indicator of cardiac dysfunction and neurohumoral activation than LF heart rate variability.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Elżbieta Domka-Jopek ◽  
Andrzej Jopek ◽  
Agnieszka Bejer ◽  
Ewa Lenart-Domka ◽  
Grzegorz Walawski

Introduction. The Six-Minute Walk Test (6MWT) is a widely used test to measure the physical performance of patients to assess the effectiveness of treatment, to qualify for rehabilitation, and to evaluate its effects..Aim.This paper focuses on the assessment of the growth of a double product (DP) during the 6MWT and its diagnostic value in the assessment of patients with heart failure.Material and Methods. The paper has retrospective character. We analyzed medical records of 412 patients hospitalized for cardiac reasons, in whom a 6MWT was performed. The patients were divided into two groups: one with diagnosed heart failure and a control group.Results. The patients with diagnosed heart failure, compared to the control group, were characterized by a shorter walking distance and greater DP increase at equal walking intervals. After distinguishing the group with the preserved and decreased left ventricle ejection fraction, the value of the DP increase was still higher compared to the control group. The mean DP increase corresponding to one meter of walk was the only one that correlated negatively with the left ventricular ejection fraction.Conclusion.The assessment of the increase of the DP during the march test seems to be a better parameter reflecting the efficiency of the myocardium from the distance of the march.


Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2198
Author(s):  
Alexandru Burlacu ◽  
Crischentian Brinza ◽  
Iolanda Valentina Popa ◽  
Adrian Covic ◽  
Mariana Floria

Psychological stress is a well-established risk factor for cardiovascular disease (CVD). Heart rate variability (HRV)-biofeedback could significantly reduce stress levels and improve autonomic nervous system function and cardiovascular endpoints. We aimed to systematically review the literature to investigate the impact of HRV modulation through HRV-biofeedback on clinical outcomes in patients with CVD. A literature search was performed in the following databases: MEDLINE (PubMed), Embase, and Cochrane from the inception until 1 October 2021. Patients in the HRV-biofeedback group had significantly lower rates of all-cause readmissions than patients who received psychological education (respectively, p = 0.028 and p = 0.001). Heart failure following HRV-biofeedback displayed an inverse association with stress and depression (respectively, p = 0.022 and p = 0.033). When stratified according to left ventricular ejection fraction (LVEF), patients with LVEF ≥ 31% showed improved values of the 6 min walk test after HRV-biofeedback interventions (p = 0.05). A reduction in systolic and diastolic blood pressure associated with HRV-biofeedback was observed (p < 0.01) in pre-hypertensive patients. HRV-biofeedback had beneficial effects on different cardiovascular diseases documented in clinical trials, such as arterial hypertension, heart failure, and coronary artery disease. A standard breathing protocol should be applied in future studies to obtain equivalent results and outcomes. However, data regarding mortality in patients with coronary artery disease are scarce and need further research.


2018 ◽  
Vol 45 (9) ◽  
pp. 1273-1280 ◽  
Author(s):  
Grégory Pugnet ◽  
Zora Marjanovic ◽  
Christophe Deligny ◽  
Karine Boussardon ◽  
Ilham Benzidia ◽  
...  

Objective.To assess the reproducibility and the utility of the 6-minute walk test (6MWT) in systemic sclerosis (SSc).Methods.All patients with SSc who underwent at least two 6MWT within a minimum 3-month interval plus simultaneous routine clinical, biological, and functional evaluations were consecutively enrolled in this observational study over 6 years. Following American Thoracic Society guidelines, each 6MWT was repeated twice to assess the 6-minute walk distance (6MWD) reproducibility, with the highest value being reported for subsequent analysis.Results.Among 56 (38 female) included patients aged 46 ± SD 12.7 years, with 17 ± 10 modified Rodnan skin score (mRSS) and 1 ± 0.8 Scleroderma Health Assessment Questionnaire (SHAQ) at first referral, 277 6MWT evaluations (5 ± 3.9 6MWT per patient) were performed over 23 ± 22.5 months followup. Meanwhile, 8 deaths (87.5% SSc-related) occurred. The mean 6MWD absolute value was 457 ± 117 m with a 4 ± 2.2 mean Borg dyspnea score. The 6MWD intraclass correlation coefficient was 0.996 (95% CI 0.995–0.999, p < 0.0001). In multivariate linear regression analysis, these factors were independently associated with a lower 6MWD: sex (R2 = 0.47, p < 0.0001), mRSS (R2 = 0.47, p = 0.008), tendon friction rub (R2 = 0.47, p = 0.003), SHAQ (R2 = 0.47, p = 0.02), muscle disability score (R2 = 0.47, p = 0.03), DLCO% (R2 = 0.47, p = 0.0008), and left ventricular ejection fraction (R2 = 0.47, p = 0.006). The 6MWD at first referral was an independent predictor for the overall mortality (HR 0.99, 95% CI 0.988–0.999) and the SSc-related mortality (HR 0.99, 95% CI 0.988–0.999).Conclusion.We show strong reproducibility for the 6MWD and confirm the 6MWT utility to assess the overall prognosis of patients with SSc.


2021 ◽  
Author(s):  
Mohanad Alkhodari ◽  
Herbert F. Jelinek ◽  
Shiza Saleem ◽  
Leontios J. Hadjileontiadis ◽  
Ahsan H. Khandoker

Abstract Analysis of heart failure is important in clinical practice to ensure coronary artery disease (CAD) patients will be provided with appropriate timely treatment. The current gold standard, echocardiography, although reliable, provides a once-off left ventricular ejection fraction (LVEF) measurement but does not provide information about heart function the during day / night cardiac cycles. The aim of this study was to investigate the ability of heart rate variability (HRV) features in classifying CAD patients into multiple LVEF groups through a new index, HRV ejection fraction (HRVEF) and its agreement to established norms. A total of 92 heart failure patients were included in this study. HRVEF groups optimized on hourly basis through Jenks natural breaks algorithm exhibited a consistent pattern with a goodness of variance fit (GVF) of more than 0.70 accuracy during the late-night to early-morning (01:00-08:00) and evening (17:00-23:00) time periods. At these hours, several HRV features were found significant in differentiating between HRVEF groups using statistical analysis of variance (ANOVA) test. These features include the successive differences between normal heartbeats (RMSSD), low and high frequency (LF, HF) power, standard deviation of normal heartbeats (SD2), short-term scaling exponent (alpha1), and percentage of normal heartbeats in alternation segments (PAS). This study paves the way towards new LVEF guidelines based on the association between LVEF and HRV features for a better demonstration of the circadian cardiac function at different LVEF levels in CAD patients.


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