Submaximal Exercise Testing in Cardiovascular Rehabilitation Settings (BEST Study)

Is breathing frequency a potential means for monitoring exercise intensity in people with atrial fibrillation and coronary heart disease when heart rate is mitigated?

PURPOSE

Moderate-intensity aerobic exercise is safe and beneficial in atrial fibrillation (AF) and coronary heart disease (CHD). Irregular or rapid heart rates (HR) in AF and other heart conditions create a challenge to using HR to monitor exercise intensity. The purpose of this study was to assess the potential of breathing frequency (BF) to monitor exercise intensity in people with AF and CHD without AF.

METHODS

This observational study included 30 AF participants (19 Male, 70.7 ± 8.7 yrs) and 67 non-AF CHD participants (38 Male, 56.9 ± 11.4 yrs). All performed an incremental maximal exercise test with pulmonary gas exchange.

RESULTS

Peak aerobic power in AF ( V ˙ O2peak; 17.8 ± 5.0 ml.kg-1.min-1) was lower than in CHD (26.7 ml.kg-1.min-1) (p < .001). BF responses in AF and CHD were similar (BF peak: AF 34.6 ± 5.4 and CHD 36.5 ± 5.0 breaths.min-1; p = .106); at the 1st ventilatory threshold (BF@VT-1: AF 23.2 ± 4.6; CHD 22.4 ± 4.6 breaths.min-1; p = .240). % V ˙ O2peak at VT-1 were similar in AF and CHD (AF: 59%; CHD: 57%; p = .656).

CONCLUSION

With the use of wearable technologies on the rise, that now include BF, this first study provides an encouraging potential for BF to be used in AF and CHD. As the supporting data are based on incremental ramp protocol results, further research is required to assess BF validity to manage exercise intensity during longer bouts of exercise.

Chronic exercise and neuropsychological function in healthy young adults: a randomised controlled trial investigating a running intervention

Despite the well-known physical and mental health benefits of regular exercise, many of the world's population, including healthy young adults, grossly undershoot recommended physical activity levels. Chronic exercise has potential to improve cognitive performance and affect in most age groups. However, there is currently a poverty of relevant research in young adults, especially randomised controlled trials. To address this, the current research investigated the effects of a running intervention on neuropsychological function (cognition and affect) in young adults. We predicted that following a running intervention, neuropsychological performance would improve alongside increases in aerobic fitness. Thirty-two healthy young adult university students were randomised (using a 3:1 ratio) into an intervention or control group, with the intervention group (n = 24) asked to run for 30 min three times a week over a 6-week period and the control group (n = 8) asked to maintain their current level of exercise over a 6-week period. We assessed fitness, cognitive performance, affect and running enjoyment at baseline and follow-up, and runners recorded the environmental conditions of their runs. Repeated measures ANCOVAs failed to find any significant effects of the running intervention on fitness or the neuropsychological measures. Anecdotal evidence supported running environment and enjoyment as potentially relevant factors. The failure to find any fitness improvements, which likely underpins the lack of neuropsychological improvements, highlights the importance of monitoring exercise sessions. Coupled with other insights gained from this trial, this article may prove useful towards future endeavours to develop exercise interventions beneficial to young adults.TRN: ACTRN12621000242820, Date of registration: 08/03/2021.

Optimization of the seat position for a personal vehicle equipped with a crankset: pilot study

The aim of the study was to optimize the seat for a personal vehicle equipped with a crankset mechanism, meant for everyday use. The inclination of the seat backrest was selected on the basis of theoretical considerations. Then dynamic tests were carried out on a group of young, healthy men in order to verify the ergonomic aspects of the seat position in relation to the crankset and determine the efficiency of the human-mechanism system with a load of 50 W. The data obtained from the dynamic tests were subject to statistical analysis. Research has shown that higher seat positions result in statistically higher efficiencies. In addition, a holistic analysis of the personal vehicle design problem shows that the upper position of the seat is also the best. The results of the research can be used to optimize personal vehicles using human force as a drive.

A Comprehensive Assessment of the Chinese Version of the Duke Activity Status Index in Patients with Cardiovascular Diseases

Background

Exercise capacity serves as a direct representation of cardiac function. The Duke Activity Status Index (DASI), a self-administered 12-item questionnaire, covers aspects of daily living, household tasks, sexual function, and physical activity. Although widely used to evaluate exercise capacity, its validation in Chinese cardiovascular disease (CVD) patients has not been thoroughly explored. Considering the significant cultural and lifestyle differences between China and Western countries, which may influence Chinese patients' comprehension and responses to DASI, our objective is to culturally adapt DASI for Chinese patients with CVD to ensure its precision in assessing exercise capacity.

Methods

The cultural adaptation of the original DASI questionnaire into Chinese followed a rigorous process to ensure its validity, reliability, and sensitivity to Chinese CVD patients. The study included 107 outpatients diagnosed with CVD who completed the DASI and cardiopulmonary exercise testing (CPET). Cronbach's alpha, Spearman correlation, and factor analysis were utilized to test reliability and validity. Receiver operating characteristic (ROC) curve analysis was employed to assess the prognostic utility of the DASI.

Results

Participants had a mean DASI score of 39.40 ± 10.75 and a peak oxygen uptake (Peak VO 2 ) of 19.53 ± 5.89 mL/min/kg. The Chinese version of the DASI exhibited satisfactory reliability and validity in CVD patients, with a Chronbach's alpha coefficient of 0.706. The DASI score demonstrated a moderate correlation with Peak VO 2 measured by CPET (r = 0.67, p < 0.001). Factor analysis yielded three factors, accounting for 56.76% of the total variance, with factor 1 contributing to 26.38% of the variance. ROC curve analysis demonstrated that the DASI exhibited discriminative utility in the identification of patients with improved long-term prognosis (p < 0.001). The ROC curve had an area of 0.788 [95% confidence interval (CI) = 0.704-0.871]. The DASI score ≥ 36.85 served as the optimal threshold for enhanced long-term prognosis, exhibiting a sensitivity of 0.80 and a specificity of 0.69.

Conclusions

The culturally adapted DASI questionnaire is a straightforward and efficient tool for reasonably evaluating exercise capacity in Chinese CVD patients.

Periodized Aerobic Training between Thresholds Improves Submaximal Cardiorespiratory Parameters in Octogenarians

BACKGROUND AND AIMS

The worldwide aging population is expanding, with more individuals living into their 80s. Physiological functions decline gradually with age, compounded by sedentary lifestyles. Incorporating physical activity into daily routine is crucial for maintaining independence. This study aimed to assess a periodized high-intensity aerobic training program (PEZO-BT) in octogenarians, focusing on submaximal ergospirometry effects.

METHODS

A total of 48 non-frail octogenarian subjects (12 females, 36 males) were randomized into control and intervention groups. All subjects underwent submaximal cardiopulmonary exercise testing with gas analysis at baseline, stopping after the respiratory compensation point (RCP). Our intervention group completed a 14-week PEZO-BT aerobic training program. The outcomes were oxygen consumption at first ventilatory threshold (VO2AT), ventilatory efficiency slope (VE/VCO2), oxygen uptake efficiency slope (OUES), cardiorespiratory optimal point (COP), oxygen pulse change (ΔVO2/HR) from anaerobic threshold (AT) to respiratory compensation point (RCP), and power output at anaerobic threshold (POAT).

RESULTS

Mixed ANOVA examined time and treatment effects. If significance emerged, post hoc t-tests were used to compare significances between groups. The homogeneity of variance was assessed using Levene's test. Chi-square tests compared ergospirometry criteria and ventilatory performance within groups. The mean differences at post intervention were significant in VO2AT (p < 0.001), VE/VCO2 (p < 0.001), ΔVO2/HR (p < 0.05), and POAT (p < 0.001), while OUES and COP were not significant (p > 0.05). However, clinical effects were observed in the entire intervention group.

CONCLUSIONS

Training improved exercise capacity and workload. Overall, this periodic aerobic and high-intensity interval training (HIIT) program yielded significant improvements in cardiorespiratory fitness (CRF) in previously untrained octogenarians with and without comorbidities. The findings suggest implications for promoting long-term healthy aging.

Maximal oxygen uptake prediction from submaximal bicycle ergometry using a differential model

The maximal oxygen uptake (VO₂max) estimation has been a subject of research for many years. Cardiorespiratory measurements during incremental tests until exhaustion are considered the golden yard stick to assess VO₂max. However, precise VO₂max determination based on submaximal tests is attractive for athlete as well for clinical populations. Here, we propose and verify such a method based on experimental data. Using a recently developed model of heart rate (HR) and VO₂ kinetics in graded exercise tests, we applied a protocol, which is terminated at 80% of the estimated maximal HR during ergometer cycling. In our approach, initially, formula for maximal HR is selected by retrospective study of a reference population (17 males, 23.5 ± 2.0 years, BMI: 23.9 ± 3.2 kg/m²). Next, the subjects for experimental group were invited (nine subjects of both sexes: 25.1 ± 2.1 years, BMI 23.2 ± 2.2 kg/m²). After calculation of maximal HR using cardiorespiratory recordings from the submaximal test, VO₂max is predicted. Finally, we compared the prediction with the values from the maximal exercise test. The differences were quantified by relative errors, which vary from 1.2% up to 13.4%. Some future improvements for the procedure of VO₂max prediction are discussed. The experimental protocol may be useful for application in rehabilitation assessment and in certain training monitoring settings, since physical exertion is not a prerequisite and the approach provides an acceptable VO₂max estimation accuracy.

Comparison of telehealth and supervised phase III cardiac rehabilitation in regional Australia: protocol for a non-inferiority trial

INTRODUCTION

Exercise-based cardiac rehabilitation programmes (ExCRP) promote recovery and secondary prevention for individuals with cardiovascular disease (CVD). Despite this, enrolment and adherence to ExCRP in rural locations is low. Telehealth programmes provide a convenient, home-based intervention, but concerns remain about compliance to exercise prescription. This paper presents the rationale and protocol design to determine if telehealth delivered ExCRP is not inferior to supervised ExCRP for improving cardiovascular function and exercise fidelity.

METHOD AND ANALYSIS

A non-inferiority, parallel (1:1), single-blinded randomised clinical trial will be conducted. Fifty patients with CVD will be recruited from a rural phase II ExCRP. Participants will be randomly assigned to telehealth or supervised ExCRP and prescribed three weekly exercise sessions for 6 weeks. Exercise sessions will include a 10 min warm up, up to 30 min of continuous aerobic exercise at a workload equivalent to the ventilatory anaerobic threshold and a 10 min cool down. The primary outcome will be change in cardiorespiratory fitness as measured by cardiopulmonary exercise test. Secondary outcome measures will include change in blood lipid profile, heart rate variability, pulse wave velocity, actigraphy measured sleep quality and training fidelity. Non-inferiority will be confirmed if intention-to-treat and per-protocol analyses conclude the same outcome following independent samples t-test with p<0.025.

ETHICS AND DISSEMINATION

Research ethics committees at La Trobe University, St John of God Health Care and Bendigo Health approved the study protocol and informed consent. Findings will be published in peer-reviewed journals and disseminated among stakeholders.

TRIAL REGISTRATION NUMBER

ACTRN12622000872730p; pre-results.

Usefulness of the Duke Activity Status Index to Assess Exercise Capacity and Predict Risk Stratification in Patients with Pulmonary Arterial Hypertension

Exercise capacity is an important component of risk assessment for pulmonary arterial hypertension (PAH). We investigated the association of the Duke Activity Status Index (DASI) with peak oxygen consumption (peakVO₂) and explored whether the DASI can discriminate the high-risk individuals in patients with PAH, according to peakVO₂ < 11 mL/min/kg. A total of 89 patients were evaluated using cardiopulmonary exercise testing (CPET) and DASI. The correlation between the DASI and peakVO₂ was measured by univariate analysis, and a receiver operating characteristic (ROC) curve analysis was conducted. The DASI was correlated with peakVO₂ in the univariate analysis. The ROC curve analysis revealed that the DASI had a discriminative value for identifying the individuals with a high risk in PAH patients (p < 0.001), with an area under ROC curve (AUC) of 0.79 (95% CI: 0.67-0.92). Similar results were observed in patients with PAH associated with congenital heart disease (CHD-PAH), (p = 0.001), with an AUC of 0.80 (95% CI: 0.658-0.947). Therefore, DASI reflects exercise capacity in patients with PAH and has good ability to discriminate patients with a low risk and a high risk, and it may be included in the risk assessment of PAH.

Does long-term exposure to air pollution suppress parasympathetic reactivation after incremental exercise among healthy males and females?

PURPOSE

As consequences of industrial processes, air pollution has led to increased cardiovascular diseases resulting in mortality. However, there are few pieces of evidence expressing physical fitness and gender impacts in such environments. Regarding long-term exposure to air pollution, this study aimed to determine the effect of physical fitness on post-exercise cardiac parasympathetic reactivation among healthy males and females.

METHODS

120 individuals (46 ± 5 years) participated and were categorized into two main groups (n = 60; EG, CG); (1) The experimental group included individuals living in an air-polluted environment; (2) The control group included the citizens of a clean air region; and two physical fitness status subgroups (n = 30; active vs. sedentary) across both sexes. The heart rate (HR) changes at different timing after performing an incremental exercise, and T30 were calculated as metrics of cardiac parasympathetic reactivation.

RESULTS

The heart rate recovery values were substantially lower in EG in comparison to CG (p < 0.001) at different timing, while, T30 was significantly greater in residents of the air-polluted city compared to CG (p < 0.001). As for heart rate recovery at the 5th minute, the values were significantly lower in the steady-female group in comparison to the active females living in the air-polluted city (p < 0.01).

CONCLUSION

Based on our findings, although physical fitness modifies the adverse impacts of long-term exposure to air pollution on post-exercise cardio-parasympathetic reactivation, it appears to parallel the acute/intermediate recovery of the thermoregulatory and vascular systems, among both sexes, it does not prevent them.

Home-based and remote functional exercise testing in cardiac conditions, during the covid-19 pandemic and beyond: a systematic review

BACKGROUND

With the change in healthcare to one that adopts a greater reliance on remote delivery, guidance regarding functional exercise testing, either in-person in the home or performed remotely, is urgently needed for people with cardiac conditions.

OBJECTIVES

To identify functional exercise tests that have been conducted in the home or remotely in patients with cardiac conditions.

DATA SOURCES

A search was undertaken across four electronic databases and grey literature for English language publications without time restrictions.

STUDY ELIGIBILITY CRITERIA

Studies of any designs were selected if they reported an exercise test conducted at home or remotely in patients with cardiac conditions.

STUDY APPRAISAL AND SYNTHESIS

Studies were independently screened and graded by two reviewers according to the Downs and Black checklist. A narrative synthesis of the included studies was undertaken.

RESULTS

Five studies (six articles) were included, with a total of 438 patients with cardiac conditions. Tests used at home or remotely were the 6-minute walk test (6MWT, five studies) and the timed up and go test (one study). No studies reported the use of step tests in the home or remotely. The 6MWTs were administered via a smartphone application, rope, videoconferencing and accelerometer and proved to be feasible, valid and reliable.

CONCLUSIONS

Despite a marked demand for home-based exercise programs, the 6MWT remains the most commonly administered functional exercise test for people with cardiac conditions. Surprisingly few studies have explored alternative tests for this patient population that may be more suitable for home or remote performance.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO: CRD42020219512.

The Physical Activity Levels and Sitting Time of Adults Living With Atrial Fibrillation: The CHAMPLAIN-AF Study

Background

The primary goal of this study was to determine the time spent completing moderate-to-vigorous intensity physical activity (MVPA) among adults with atrial fibrillation (AF). Secondary aims examined MVPA and sitting time (ST) by AF subtypes (ie, paroxysmal, persistent, long-standing persistent, and permanent) and associations between MVPA or ST and knowledge, task self-efficacy, and outcome expectations.

Methods

An observational study was conducted in the Champlain region of Ontario, Canada. AF patients completed a survey to determine MVPA and ST using the Short-Form International Physical Activity Questionnaire.

Results

A total of 619 patients (66% male; median age 65 years [95% CI 64-67 years]) completed the survey. Median MVPA and ST were 100 (60-120) min/wk and 6 (5-6) h/d; 56% of patients were not meeting the Canadian 24H Movement Guidelines. Most patients (54%) did not know/were unsure of the MVPA recommendations, yet 72% thought physical activity should be part of AF management. Positive correlations were found between higher MVPA levels and the following: (i) speaking to a healthcare professional about engaging in physical activity for managing AF (ρ = 0.108, P = 0.017); (ii) greater confidence regarding ability to perform physical activity and muscle-strengthening exercise (ρ = 0.421, P < 0.01); and (iii) patient agreement that AF would be better managed if they were active (ρ = 0.205, P < 0.01).

Conclusions

Many AF patients do not meet the MVPA recommendations, which may be due to lack of physical activity knowledge. Exercise professionals may help educate patients on the benefits of physical activity, improve task-self efficacy, and integrate MVPA into patient lifestyles.

Which functional outcome measures can we use as a surrogate for exercise capacity during remote cardiopulmonary rehabilitation assessments? A rapid narrative review

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic has seen many cardiopulmonary rehabilitation services delivering programmes remotely. One area of concern is how to assess exercise capacity when a supervised exercise test is not possible. The aim of this review was to examine the relationship between functional exercise tests and recommended exercise tests for cardiopulmonary rehabilitation.

METHODS

A rapid narrative review was carried out. Searches were conducted by two of the study authors. The study had the following features. Participants: adults, all with long-term conditions; intervention: any/none; outcome: Duke activity status index (DASI), sit to stand (STS, 30 s, 1 min and 5 repetitions), short physical performance battery (SPPB), 4-metre gait speed (4MGS) or step test (Chester/others) AND directly compared to one of the recommended exercise tests for cardiopulmonary rehabilitation: 6-min walk test (6MWT), incremental shuttle walk test (ISWT) or cardiopulmonary exercise test (CPET) in terms of reporting agreement/correlation; Study design: primary research only, controlled trials or observational studies.

RESULTS

Sixteen articles out of 249 screened were included (n=2271 patients). Overall, there were weak-strong correlations for the included tests with a recommended exercise test (r=0.38-0.85). There were few reported issues with feasibility or safety of the tests. However, all tests were supervised in a clinical setting. The test that had the highest correlation with the field walking test was the 4MGS with the ISWT (r=0.78) and with the 6MWT (r=0.85).

DISCUSSION

The 4MGS has the highest correlation with routine measures of exercise tolerance. However, it may be difficult to standardise in a remote assessment or to prescribe exercise from. Clinicians should strive for face-to-face standardised exercise tests where possible to be able to guide exercise prescription.