Dynamics of cardiorespiratory response during and after the six-minute walk test in patients with heart failure

Walking Endurance and Oxygen Uptake On-Kinetics in Individuals With Parkinson Disease Following Overground Locomotor Training

BACKGROUND AND PURPOSE

Poor walking endurance in Parkinson disease (PD) may be attributable to both bioenergetic and biomechanical factors, but locomotor training methods addressing both these factors simultaneously are understudied. Our objective was to examine the effects of overground locomotor training (OLT) on walking endurance in individuals with mild-to-moderate PD, and to further explore potential cardiorespiratory contributions.

METHODS

A single-arm, longitudinal design was used to examine the effects of 24 biweekly sessions of OLT in people with mild-to-moderate PD (n = 12). Walking endurance was measured as total distance walked during a 10-minute walk test (10minWT). Oxygen uptake (V˙ o2 ) on-kinetic profiles were determined using a monoexponential function. Perceived fatigability was assessed following the 10minWT using a self-report scale. Magnitude of change in primary outcomes was assessed using Cohen's d and adjusted for sample size (Cohen's d(unbiased) ).

RESULTS

Participants executed 3036 (297) steps and maintained 65.5% (8%) age-predicted heart rate maximum in a typical session lasting 56.9 (2.5) minutes. Medium effects in total distance walked-885.9 (157.2) versus 969.5 (140.9); Cohen's d(unbiased) = 0.54-and phase II time constant of the V˙ o2 on-kinetic profile-33.7 (12.3) versus 25.9 (15.3); Cohen's d(unbiased) = 0.54-were observed alongside trivial effects for perceived fatigability-4.7 (1.4) versus 4.8 (1.5); Cohen's d(unbiased) = 0.11-following OLT.

DISCUSSION AND CONCLUSIONS

These preliminary findings may demonstrate the potential for moderate-intensity OLT to improve walking endurance and enhance cardiorespiratory adjustments to walking activity in adults with mild-to-moderate PD.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A407 ).

Individually tailored home-based physiotherapy program makes sustainable improvement in exercise capacity and daily physical activity in patients with pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a rare, chronic, progressive, and life-threatening cardiopulmonary disease. This study investigated the impact of an individually tailored 12 weeks home-based physiotherapy program in PAH patients, with the aim to evaluate change in exercise capacity and daily physical activity level.

METHODS

This was an analysis of secondary outcomes from a prospective, randomized, controlled intervention study. Twenty-one participants were recruited from the Latvian PH registry based on inclusion criteria and randomized in a training group (TG) and control group (CG). Both groups continued a medical target therapy, but for TG, the individually tailored home-based physiotherapy program was added including physical exercises, relaxation, self-control, education, and supervision with telehealth elements. Outcomes included a 6-min walk test (6MWT) (m) and daily physical activity based on accelerometry results assessed at baseline, after 12 weeks, and at follow-up 6 months after commencement of intervention.

RESULTS

6MWT distance significantly (p < 0.05) and clinically (>33 m) increased within TG after 12 weeks (51.8 m, 95% CI = 25.7-77.9 m, Cohen's d = 1.7) and at follow-up (75.5 m, 95% CI = 46.1-104.8 m, Cohen's d = 2.1). A significant difference in 6MWT results between the groups at 12 weeks and follow-up was approved. In TG, low-intensity activities significantly (p < 0.05) increased both after 12 weeks (Cohen's d = 1.6) and at follow-up (Cohen's d = 1.2), moderate-intensity activities significantly (p < 0.05) increased at follow-up (Cohen's d = 1.3), and no significant improvements were present in CG.

CONCLUSION

The individually tailored 12 weeks home-based physiotherapy program comprising comprehensive physical exercise training, relaxation, self-control skills training, and education, added to stable medical target therapy and supervised by physiotherapist through telehealth elements, is effective in improving exercise capacity and increasing daily time in low or moderate physical activities 6 months after commencement of the intervention in patients with PAH.

The prospects for NT-pro BNP level determining in physical activity conditions in patients during the rehabilitation period after the myocardial infarction, complicated with decompensated heart failure

The aim of the study was to determine the futility of NT-pro BNP level analysis during dosed physical exercise for diagnosing decompensated HF in the postinfarction period and the possibility to determine the HF functional class. Materials and methods. 160 patients with previous MI were examined, patients’ average age was (56.67±5.72) years. The patients were randomized in 2 groups dependently on the presence of the signs of II А-B according to V. Kh. Vasylenko and M. D. Strazhesko classification and FC III-IV (according to NYHA) decompensated chronic HF. Group I consisted of 120 patients with Q-QS and non-Q MI; group II (the control one) had 40 patients with MI without signs of decompensated HF; 20 healthy people made up a norm group. Results. Signs of coronary insufficiency such as dizziness and signs of poor peripheral perfusion (cyanosis/paleness) occurred in 104 (86.7 %) and 79 (65.8 %) cases that differ from the same values in the second group 4 (10.0 %) and 14 (35.0 %) respectively. 88 (73.3 %) patients with the signs of decompensated HF felt general weakness, fatigue, and expressed a request to stop the test. The HR in the postinfarction patients with the signs of decompensated HF was before the exercise (88.2±3.18) bpm (p≤0.05); in the patients with past MI without the signs of decompensated HF, it was (75.32±3.41) bpm (p≤0.05); and in the practically healthy people, it was (77.73±3.02) bpm. We found out a reverse moderate correlation between the distances that had been covered by a patient during the 6MWT NT-proBNP level in blood serum of examined patients. Conclusions. Inadequate response to dosed physical exercises and increased immunological parameters as quantitative HF markers could be useful not only for diagnostics, but also for the risk stratification for decompensated HF that had occurred in patients on different rehabilitation stages after an acute MI.

6-minute walking test: a useful tool in the management of heart failure patients

Reduced functional ability and exercise tolerance in patients with heart failure (HF) are associated with poor quality of life and a worse prognosis. The 6-minute walking test (6MWT) is a widely available and well-tolerated test for the assessment of the functional capacity of patients with HF. Although the cardiopulmonary exercise test (a maximal exercise test) remains the gold standard for the evaluation of exercise capacity in patients with HF, the 6MWT (submaximal exercise test) may provide reliable information about the patient’s daily activity. The current review summarizes the value of 6MWT in patients with HF and identifies its usefulness and limitations in everyday clinical practice in populations of HF. We aimed to investigate potential associations of 6MWD with other measures of functional status and determinants of 6MWD in patients with HF as well as to review its prognostic role and changes to various interventions in these patients.

Association between early pulmonary complications after abdominal surgery and preoperative physical capacity

Objective: To investigate whether early postoperative pulmonary complications after abdominal surgery are associated with a lower performance in preoperative six-minute walk test.Methods: A cross-sectional cohort study of 50 participants who underwent elective abdominal surgery and performed the six-minute walk test within 48 hours prior to surgery were conducted. Postoperative pulmonary complications up to the seventh postoperative day were obtained from medical records.Results: Overall, 25 participants developed postoperative pulmonary complications. The mean (standard deviation) preoperative walked distances of the participants with and without postoperative pulmonary complications were, respectively, 444.8 (81.3) meters and 498.3 (63.7) meters (p = .013). The incidence of postoperative pulmonary complications was greater in the participants with walked distance < 400 meters. The multivariable logistic regression model revealed a significant association between postoperative pulmonary complications and preoperative walked distance (Odds ratio = 0.978, p = .010) in participants who underwent intestinal, stomach, or bile tract resection. Conclusions: This study found a high incidence of postoperative pulmonary complications in abdominal surgery participants and an association between lower preoperative physical capacity and the risk of postoperative pulmonary complications in participants who underwent intestinal, stomach, and biliary tract resection.

Comparison of functional and maximal exercise capacity, respiratory and peripheral muscle strength, dyspnea, and fatigue in patients with heart failure with pacemakers and healthy controls: a cross-sectional study

Background: Despite major breakthroughs that have recently been made in pacemakers implanted in patients with heart failure (HF), it is clear that functional impairments and symptoms often remain. However, only limited studies have investigated exercise capacity, muscle strength, pulmonary function, dyspnea, and fatigue in these patients. Therefore, we aimed to compare aforementioned outcomes in patients and healthy controls. Methods: A cross-sectional study. Fifty patients with HF with pacemakers (58.90 ± 10.69 years, NYHA II-III, LVEF: 30.79 ± 8.78%) and 40 controls (56.33 ± 5.82 years) were compared. Functional (6-Minute Walking test (6-MWT)) and maximal exercise capacity (Incremental Shuttle Walk test (ISWT)), respiratory (Mouth pressure device) and peripheral muscle strength (Dynamometer), pulmonary function (Spirometry), dyspnea (Modified Medical Research Council Dyspnea scale), and fatigue (Fatigue Severity scale) were evaluated. ClinicalTrial number: NCT03701854. Results: 6-MWT (412.62 ± 96.51 m versus 610.16 ± 59.48 m) and ISWT (279.97 m versus 655 m) distances (p ˂ 0.001), pulmonary function (p˂0.001), respiratory and peripheral muscle strength (p ˂ 0.001) were significantly lower; dyspnea (p ˂ 0.001) and fatigue (p = .030) scores were higher in patients compared with controls. Conclusion: Maximal and functional exercise capacity is impaired in the majority of patients with HF with pacemakers, respiratory and peripheral muscles are weakened, dyspnea and fatigue perceptions are increased. Patients with pacemakers have to be included in cardiac rehabilitation programs to improve impairments.

Electrocardiogram-Derived Tidal Volume During Treadmill Stress Test

OBJECTIVE

Electrocardiogram (ECG) has been regarded as a source of respiratory information with the main focus in the estimation of the respiratory rate. Although little research concerning the estimation of tidal volume (TV) has been conducted, there are several ECG-derived features that have been related with TV in the literature, such as ECG-derived respiration, heart rate variability, and respiratory rate. In this paper, we exploited these features for estimating TV using a linear model.

METHODS

25 young (33.4 ± 5.2 years) healthy male volunteers were recruited for performing a maximal (MaxT) and a submaximal (SubT) treadmill stress test, which were conducted on different days. Both tests were automatically segmented in stages attending to the heart rate. Afterwards, a subject-specific TV model was calibrated for each stage, employing features from MaxT, and the model was later used for estimating the TV in SubT.

RESULTS

During exercise, the different proposed approaches led to relative fitting errors lower than 14% in most of the cases and 6% in some of them.

CONCLUSION

Low achieved fitting errors suggest that TV can be estimated from ECG during a treadmill stress test.

SIGNIFICANCE

The results suggest that it is possible to estimate TV during exercise using only ECG-derived features.

A systematic comparison of exercise training protocols on animal models of cardiovascular capacity

Cardiovascular disease (CVD) is a major global cause of mortality, which has prompted numerous studies seeking to reduce the risk of heart failure and sudden cardiac death. While regular physical activity is known to improve CVD associated morbidity and mortality, the optimal duration, frequency, and intensity of exercise remains unclear. To address this uncertainty, various animal models have been used to study the cardioprotective effects of exercise and related molecular mechanism such as the mice training models significantly decrease size of myocardial infarct by affecting Kir6.1, VSMC sarc-K_ATP channels, and pulmonary eNOS. Although these findings cement the importance of animal models in studying exercise induced cardioprotection, the vast assortment of exercise protocols makes comparison across studies difficult. To address this issue, we review and break down the existent exercise models into categories based on exercise modality, intensity, frequency, and duration. The timing of sample collection is also compared and sorted into four distinct phases: pre-exercise (Phase I), mid-exercise (Phase II), exercise recovery (Phase III), and post-exercise (Phase IV). Finally, because the life-span of animals so are limited, small changes in animal exercise duration can corresponded to untenable amounts of human exercise. To address this limitation, we introduce the Life-Span Relative Exercise Time (RET_{life span}) as a method of accurately defining short-term, medium-term and long-term exercise relative to the animal's life expectancy. Systematic organization of existent protocols and this new system of defining exercise duration will allow for a more solid framework from which researchers can extrapolate animal model data to clinical application.