Effects of exercise rehabilitation program on heart rate recovery in patients with chronic heart failure:

A systematic review of rehabilitation in chronic heart failure: evaluating the reporting of exercise interventions

A large body of research supports the use of exercise to improve symptoms, quality of life, and physical function in patients with chronic heart failure. Previous reviews have focused on reporting outcomes of exercise interventions such as cardiorespiratory fitness. However, none have critically examined exercise prescription. The aim of this review was to evaluate the reporting and application of exercise principles in randomised control trials of exercise training in patients with chronic heart failure. A systematic review of exercise intervention RCTs in patients with CHF, using the Consensus on Exercise Reporting Template (CERT), was undertaken. The Ovid Medline/PubMed, Embase, Scopus/Web of Science, and Cochrane Library and Health Technology Assessment Databases were searched from 2000 to June 2020. Prospective RCTs in which patients with CHF were randomized to a structured exercise programme were included. No limits were placed on the type or duration of exercise structured exercise programme or type of CHF (i.e. preserved or reduced ejection fraction). We included 143 studies, comprising of 181 different exercise interventions. The mean CERT score was 10 out of 19, with no study achieving a score of 19. Primarily, details were missing regarding motivational strategies, home-based exercise components, and adherence/fidelity to the intervention. Exercise intensity was the most common principle of exercise prescription missing from intervention reporting. There was no improvement in the reporting of exercise interventions with time (R²  = 0.003). Most RCTs of exercise training in CHF are reported with insufficient detail to allow for replication, limiting the translation of evidence to clinical practice. We encourage authors to provide adequate details when reporting future interventions. Where journal word counts are restrictive, we recommend using supplementary material or publishing trial protocols prior to beginning the study.

The effect of cardiac rehabilitation on blood pressure, and on left atrial and ventricular functions in hypertensive patients

PURPOSE

Hypertension is associated with left ventricular (LV) hypertrophy, impaired LV relaxation, and left atrial (LA) enlargement. Cardiac rehabilitation (CR) improves clinical outcomes in a broad spectrum of cardiac disease. The aim of our study was to determine the effect of CR on blood pressure (BP), and on LA and LV functions in hypertensive patients.

METHODS

Thirty consecutive hypertensive patients who would undergo CR program, and 38 hypertensive patients who refused to undergo CR program were included. All patients underwent ambulatory BP monitoring and transthoracic echocardiography, which were repeated after completion of the CR program, or 12 weeks later in the control group. LA and LV functions were assessed by both speckle tracking and 3-dimensional echocardiography. N-terminal pro-brain natriuretic peptide (NT-proBNP) levels were assessed before and after CR.

RESULTS

Although initial ambulatory BP values and NT-proBNP levels were similar between the groups, daily, day-time, and night-time BP and NT-proBNP were significantly lower in the CR group after rehabilitation. LA reservoir strain and LV global longitudinal strain of the CR group significantly increased after CR while no significant increase was observed in controls.

CONCLUSION

CR improves LA and LV strain while lowering BP and should be encouraged in routine management of hypertensive patients.

High-Intensity Interval Training for Patients With Cardiovascular Disease-Is It Safe? A Systematic Review

Background

Cardiac rehabilitation (CR) for patients with cardiovascular disease has traditionally involved low‐ to moderate‐intensity continuous aerobic exercise training (MICT). There is growing and robust evidence that high‐intensity interval training (HIIT) shows similar or greater efficacy compared with MICT across a range of cardiovascular and metabolic measures, in both healthy populations and populations with a chronic illness. However, there is understandable concern about the safety aspects of applying HIIT in CR settings. This systematic review analyzed safety data drawn from recent proof‐of‐concept studies of HIIT during CR among patients with cardiovascular disease.

Methods and Results

We included trials comparing HIIT with either MICT or usual care in patients with coronary artery disease or heart failure participating in tertiary care services, such as phase 2 (outpatient) CR. Adverse events occurring during or up to 4 hours after an exercise training session were collated. There were 23 studies included, which analyzed 1117 participants (HIIT=547; MICT=570). One major cardiovascular adverse event occurred in relation to an HIIT session, equating to 1 major cardiovascular event per 17 083 training sessions (11 333 training hours). One minor cardiovascular adverse events and 3 noncardiovascular adverse events (primarily musculoskeletal complaints) were also reported for HIIT. Two noncardiovascular events were reported in relation to MICT.

Conclusions

HIIT has shown a relatively low rate of major adverse cardiovascular events for patients with coronary artery disease or heart failure when applied within CR settings.

Association between heart rate recovery after exercise and renal function in patients referred for treadmill exercise test

Introduction

Heart rate recovery (HRR) is a marker of parasympathetic activity recovery after exercise, and it is associated with cardiovascular mortality and total mortality. Impaired renal function is also associated with cardiac mortality. The aim of this study was to investigate the association between HRR after exercise and renal function in patients referred for a treadmill exercise test.

Patients and methods

This cross-sectional study was conducted at a regional hospital in southern Taiwan. Patients who completed a symptom-limited treadmill exercise test from January 2015 to February 2018 were recruited. Before the treadmill exercise test, patients were asked to complete a questionnaire on the past disease history and lifestyle factors. Serum creatinine measurement within two years prior to or after the date of the treadmill exercise test of the patients was also obtained from the medical records for these patients. Estimated glomerular filtration rate (eGFR) was calculated. Simple and multiple linear regression analyses were performed to investigate the association between one-minute HRR and eGFR.

Results

A total of 2,825 patients completed the treadmill exercise test, and serum creatinine measurement was identified from medical records for 2,153 patients (76.2%). Multiple linear regression analysis revealed that a lower eGFR was significantly associated with lower one-minute HRR (P< 0.001), adjusting for other significant independent factors, including age, waist circumference, type 2 diabetes mellitus, and smoking.

Conclusions

In this cross-sectional observational study, a lower eGFR was significantly and independently associated with decreased one-minute HRR, suggesting that parasympathetic activity recovery after exercise could be impaired by a decrease in renal function.

Aerobic Interval vs. Continuous Training in Patients with Coronary Artery Disease or Heart Failure: An Updated Systematic Review and Meta-Analysis with a Focus on Secondary Outcomes

BACKGROUND

In a previous meta-analysis including nine trials comparing aerobic interval training with aerobic continuous training in patients with coronary artery disease, we found a significant difference in peak oxygen uptake favoring aerobic interval training.

OBJECTIVE

The objective of this study was to (1) update the original meta-analysis focussing on peak oxygen uptake and (2) evaluate the effect on secondary outcomes.

METHODS

We conducted a systematic review with a meta-analysis by searching PubMed and SPORTDiscus databases up to March 2017. We included randomized trials comparing aerobic interval training and aerobic continuous training in patients with coronary artery disease or chronic heart failure. The primary outcome was change in peak oxygen uptake. Secondary outcomes included cardiorespiratory parameters, cardiovascular risk factors, cardiac and vascular function, and quality of life.

RESULTS

Twenty-four papers were identified (n = 1080; mean age 60.7 ± 10.7 years). Aerobic interval training resulted in a higher increase in peak oxygen uptake compared with aerobic continuous training in all patients (1.40 mL/kg/min; p < 0.001), and in the subgroups of patients with coronary artery disease (1.25 mL/kg/min; p = 0.001) and patients with chronic heart failure with reduced ejection fraction (1.46 mL/kg/min; p = 0.03). Moreover, a larger increase of the first ventilatory threshold and peak heart rate was observed after aerobic interval training in all patients. Other cardiorespiratory parameters, cardiovascular risk factors, and quality of life were equally affected.

CONCLUSION

This meta-analysis adds further evidence to the clinically significant larger increase in peak oxygen uptake following aerobic interval training vs. aerobic continuous training in patients with coronary artery disease and chronic heart failure. More well-designed randomized controlled trials are needed to establish the safety of aerobic interval training and the sustainability of the training response over longer periods.

High-intensity Interval Training Dosage for Heart Failure and Coronary Artery Disease Cardiac Rehabilitation. A Systematic Review and Meta-analysis

INTRODUCTION AND OBJECTIVES

High-interval intensity training (HIT) has been suggested to improve peak VO₂ in cardiac rehabilitation programs. However, the optimal HIT protocol is unknown. The objective of this study was to identify the most effective doses of HIT to optimize peak VO₂ in coronary artery disease (CAD) and heart failure (HF) patients.

METHODS

A search was conducted in 6 databases (MEDLINE, Web of Science, LILACS, CINAHL, Academic Search Complete, and SportDiscus). Studies using a HIT protocol in CAD or HF patients and measuring peak VO₂ were included. The PEDro Scale and Cochrane Collaboration tools were used.

RESULTS

Analyses reported significant improvements in peak VO₂ after HIT in both diseases (P = .000001), with a higher increase in HF patients (P = .03). Nevertheless, in HF patients, there were no improvements when the intensity recovery was ≤ 40% of peak VO₂ (P = .19) and the frequency of training was ≤ 2 d/wk (P = .07). There were significant differences regarding duration in CAD patients, with greater improvements in peak VO₂ when the duration was < 12 weeks (P = .05). In HF, programs lasting < 12 weeks did not significantly improve peak VO₂ (P = .1).

CONCLUSIONS

The HIT is an effective method for improving peak VO₂ in HF and CAD, with a significantly greater increase in HF patients. The recovery intervals should be active and be between 40% and 60% of peak VO₂ in HF patients. Training frequency should be ≥ 2 d/wk for CAD patients and ≥ 3 d/wk for HF patients.

High intensity interval training versus moderate intensity continuous training on exercise capacity and quality of life in patients with heart failure with reduced ejection fraction: A systematic review and meta-analysis

OBJECTIVE

The aim of this study was to investigate the effects of high intensity interval training (HIIT) versus moderate intensity continuous training (MICT) in heart failure patients with reduced ejection fraction (HFrEF).

BACKGROUND

Despite the well-known positive effects of exercise in heart failure patients, the best mode of exercise is still under discussion.

METHODS

We searched Pubmed/MEDLINE, Cochrane Central Register of Controlled Trials, PEDro data base, and SciELO (from the earliest date available to October 2017) for randomized controlled trials that evaluated the effects of HIIT versus MICT in HFrEF patients. Weighted mean differences (WMD) with 95% confidence interval (CI) were calculated, and heterogeneity was assessed using the I² test.

RESULTS

13 studies met the study criteria, including 411 patients. Compared to MICT, HIIT resulted in improvement in Peak VO₂ WMD (1.35 mL·kg^-1·min^-1 95% CI: 0.03 to 2.64 N = 411). HIIT resulted in no difference in VE/VCO₂ slope WMD (-1.21 95% CI: -3.0 to 0.58 N = 135), and quality of life measured by Minnesota Living with Heart Failure questionnaire WMD (1.19 95% CI: -5.81 to 8.19 N = 79). Sub-group analyses comparing studies with and without isocaloric exercise training protocol also showed a nonsignificant difference in peak VO₂ for participants in the HIIT group compared with MICT group.

CONCLUSIONS

HIIT improves peak VO₂ and should be considered as a component of care of HFrEF patients. However, its superiority versus MICT disappears when isocaloric protocols are compared. An important caveat is uncertainty and variation of actual training intensities compared to program targets.

Molecular effects of exercise training in patients with cardiovascular disease: focus on skeletal muscle, endothelium, and myocardium

For decades, we have known that exercise training exerts beneficial effects on the human body, and clear evidence is available that a higher fitness level is associated with a lower incidence of suffering premature cardiovascular death. Despite this knowledge, it took some time to also incorporate physical exercise training into the treatment plan for patients with cardiovascular disease (CVD). In recent years, in addition to continuous exercise training, further training modalities such as high-intensity interval training and pyramid training have been introduced for coronary artery disease patients. The beneficial effect for patients with CVD is clearly documented, and during the last years, we have also started to understand the molecular mechanisms occurring in the skeletal muscle (limb muscle and diaphragm) and endothelium, two systems contributing to exercise intolerance in these patients. In the present review, we describe the effects of the different training modalities in CVD and summarize the molecular effects mainly in the skeletal muscle and cardiovascular system.

The Correlation of Decreased Heart Rate Recovery and Chronotropic Incompetence with Exercise Capacity in Idiopathic Pulmonary Arterial Hypertension Patients

We show by this study that a decrease in HRR1 in IPAH patients is associated with severe limitation of exercise capacity. HRR1 < 16 beats and CI just after completion of a CPET could be an indicator of poor prognosis.

Effects of High-Intensity Interval Training on Aerobic Capacity in Cardiac Patients: A Systematic Review with Meta-Analysis

Purpose. The aim of this study was to compare the effects of high-intensity interval training (INTERVAL) and moderate-intensity continuous training (CONTINUOUS) on aerobic capacity in cardiac patients. Methods. A meta-analysis identified by searching the PubMed, Cochrane Library, EMBASE, and Web of Science databases from inception through December 2016 compared the effects of INTERVAL and CONTINUOUS among cardiac patients. Results. Twenty-one studies involving 736 participants with cardiac diseases were included. Compared with CONTINUOUS, INTERVAL was associated with greater improvement in peak VO₂ (mean difference 1.76 mL/kg/min, 95% confidence interval 1.06 to 2.46 mL/kg/min, p < 0.001) and VO₂ at AT (mean difference 0.90 mL/kg/min, 95% confidence interval 0.0 to 1.72 mL/kg/min, p = 0.03). No significant difference between the INTERVAL and CONTINUOUS groups was observed in terms of peak heart rate, peak minute ventilation, VE/VCO₂ slope and respiratory exchange ratio, body mass, systolic or diastolic blood pressure, triglyceride or low- or high-density lipoprotein cholesterol level, flow-mediated dilation, or left ventricular ejection fraction. Conclusions. This study showed that INTERVAL improves aerobic capacity more effectively than does CONTINUOUS in cardiac patients. Further studies with larger samples are needed to confirm our observations.

Effect of High-Intensity Interval Versus Continuous Exercise Training on Functional Capacity and Quality of Life in Patients With Coronary Artery Disease: A RANDOMIZED CLINICAL TRIAL

PURPOSE

There is strong evidence that exercise training has beneficial health effects in patients with cardiovascular disease. Most studies have focused on moderate continuous training (MCT); however, a body of evidence has begun to emerge demonstrating that high-intensity interval training (HIIT) has significantly better results in terms of morbidity and mortality. The aim of this study was to compare the effects of MCT versus HIIT on functional capacity and quality of life and to assess safety.

METHODS

Seventy-two patients with ischemic heart disease were assigned to either HIIT or MCT for 8 weeks. We analyzed cardiopulmonary exercise test data, quality of life, and adverse events.

RESULTS

High-intensity interval training resulted in a significantly greater increase in (Equation is included in full-text article.)O2peak (4.5 ± 4.7 mL·kg·min) compared with MCT (2.5 ± 3.6 mL·kg·min) (P < .05). The aerobic threshold (VT1) increased by 21% in HIIT and 14% in MCT. Furthermore, there was a significant (P < .05) increase in the distance covered in the 6-minute walk distance test in the HIIT group (49.6 ± 6.3 m) when compared with the MCT group (29.6 ± 12.0 m). Both training protocols improved quality of life. No adverse events were reported in either of the groups.

CONCLUSIONS

On the basis of the results of this study, HIIT should be considered for use in cardiac rehabilitation as it resulted in a greater increase in functional capacity compared with MCT. We also observed greater improvement in quality of life without any increase in cardiovascular risk.

Exercise training-induced modification in autonomic nervous system: An update for cardiac patients

Patients with cardiovascular disease show autonomic dysfunction, including sympathetic activation and vagal withdrawal, which leads to fatal events. This review aims to place sympathovagal balance as an essential element to be considered in management for cardiovascular disease patients who benefit from a cardiac rehabilitation program. Many studies showed that exercise training, as non-pharmacologic treatment, plays an important role in enhancing sympathovagal balance and could normalize levels of markers of sympathetic flow measured by microneurography, heart rate variability or plasma catecholamine levels. This alteration positively affects prognosis with cardiovascular disease. In general, cardiac rehabilitation programs include moderate-intensity and continuous aerobic exercise. Other forms of activities such as high-intensity interval training, breathing exercises, relaxation and transcutaneous electrical stimulation can improve sympathovagal balance and should be implemented in cardiac rehabilitation programs. Currently, the exercise training programs in cardiac rehabilitation are individualized to optimize health outcomes. The sports science concept of the heart rate variability (HRV)-vagal index used to manage exercise sessions (for a goal of performance) could be implemented in cardiac rehabilitation to improve cardiovascular fitness and autonomic nervous system function.

Comparing exercise training modalities in heart failure: A systematic review and meta-analysis

Exercise training (ET) is suggested to improve exercise capacity, prognosis, quality of life (QOL) and functional modifications of the heart in patients with heart failure (HF). However, it is not clear which modality is best. In order to assess the effectiveness of different ET modalities on prognostic cardiopulmonary exercise test (CPET) parameters, QOL and left ventricular remodeling, a systematic review and meta-analysis was performed. Randomized clinical trials (RCTs) were selected in three databases. The primary outcome data were peak oxygen uptake, ventilation over carbon dioxide slope, oxygen uptake efficiency slope, exercise oscillatory ventilation, rest and peak pulmonary end-tidal CO2. Secondary variables were QOL, left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDD). Twenty RCTs (n=811) met the a priori stated inclusion criteria. Studies were categorized into four different groups: "interval training (IT1) versus combined interval and strength training (IT1S)" (n=156), "continuous training (CT1) versus combined continuous and strength training (CT1S)" (n=130), "interval training (IT2) versus continuous training (CT2)" (n=501) and "continuous training (CT3) versus strength training (S3)" (n=24). No significant random effects of exercise modality were revealed assessing the CPET parameters. There was a significant improvement in QOL applying CT1S (P<0.001). Comparing IT2 with CT2, LVEDD and LVEF were significantly improved favoring IT2 (P<0.001). There is some evidence to support that interval training is more effective to improve LVEF and LVEDD. The fact that patients with HF are actively involved in any kind of ET program seems sufficient to improve the prognosis, QOL and anatomic function.

Review of High-intensity Interval Training in Cardiac Rehabilitation

For the secondary prevention of cardiovascular disease, comprehensive cardiac rehabilitation is required. This involves optimal medical therapy, education on nutrition and exercise therapy, and smoking cessation. Of these, efficient exercise therapy is a key factor. A highly effective training protocol is therefore warranted, which requires a high rate of compliance. Although moderate-intensity continuous training has been the main training regimen recommended in cardiac rehabilitation guidelines, high-intensity interval training has been reported to be more effective in the clinical and experimental setting from the standpoint of peak oxygen uptake and central and peripheral adaptations. In this review, we illustrate the scientific evidence for high-intensity interval training. We then verify this evidence and discuss its significance and the remaining issues.

Effects of High-Intensity Interval Training versus Continuous Training on Physical Fitness, Cardiovascular Function and Quality of Life in Heart Failure Patients

Introduction

Physical fitness is an important prognostic factor in heart failure (HF). To improve fitness, different types of exercise have been explored, with recent focus on high-intensity interval training (HIT). We comprehensively compared effects of HIT versus continuous training (CT) in HF patients NYHA II-III on physical fitness, cardiovascular function and structure, and quality of life, and hypothesize that HIT leads to superior improvements compared to CT.

Methods

Twenty HF patients (male:female 19:1, 64±8 yrs, ejection fraction 38±6%) were allocated to 12-weeks of HIT (10*1-minute at 90% maximal workload—alternated by 2.5 minutes at 30% maximal workload) or CT (30 minutes at 60–75% of maximal workload). Before and after intervention, we examined physical fitness (incremental cycling test), cardiac function and structure (echocardiography), vascular function and structure (ultrasound) and quality of life (SF-36, Minnesota living with HF questionnaire (MLHFQ)).

Results

Training improved maximal workload, peak oxygen uptake (VO_2peak) related to the predicted VO_2peak, oxygen uptake at the anaerobic threshold, and maximal oxygen pulse (all P<0.05), whilst no differences were present between HIT and CT (N.S.). We found no major changes in resting cardiovascular function and structure. SF-36 physical function score improved after training (P<0.05), whilst SF-36 total score and MLHFQ did not change after training (N.S.).

Conclusion

Training induced significant improvements in parameters of physical fitness, although no evidence for superiority of HIT over CT was demonstrated. No major effect of training was found on cardiovascular structure and function or quality of life in HF patients NYHA II-III.

Trial Registration

Nederlands Trial Register NTR3671

Possible neurocognitive benefits of exercise in persons with heart failure

More than 6 million Americans have heart failure (HF) and more than 500,000 are diagnosed each year. In addition to its many adverse medical consequences, HF is also a significant risk factor for neurological disorders like Alzheimer's disease and associated with cognitive impairment long prior to the onset of these conditions. Converging bodies of literature suggest cognitive dysfunction in HF may be at least partially modifiable. One key mechanism for cognitive improvement is improved cerebral blood flow, which may be possible with exercise in patients with HF. This brief review provides a model for the likely neurocognitive benefits of exercise in HF and encourages further work in this area.

Effects of Exercise Training on Autonomic Function in Chronic Heart Failure: Systematic Review

Objectives. Cardiac autonomic imbalance accompanies the progression of chronic heart failure (CHF). It is unclear whether exercise training could modulate autonomic control in CHF. This study aimed to review systematically the effects of exercise training on heart rate recovery (HRR) and heart rate variability (HRV) in patients with CHF. Methods. Literatures were systematically searched in electronic databases and relevant references. Only published randomized controlled trials (RCTs) focusing on exercise training for CHF were eligible for inclusion. Outcome measurements included HRR and HRV parameters. Results. Eight RCTs were eligible for inclusion and provided data on 280 participants (186 men). The participants were 52–70 years of age with New York Heart Association functional class II-III of CHF. Each study examined either aerobic or resistance exercise. Two trials addressed outcome of HRR and six HRV among these studies. Two RCTs showed that moderate aerobic exercise could improve HRR at 2 minutes after exercise training in CHF. Five of six RCTs demonstrated positive effects of exercise training on HRV which revealed the increments in high frequency (HF) and decrements in LF (low frequency)/HF ratio after training. Conclusion. Participation in an exercise training program has positive effects on cardiac autonomic balance in patients with CHF.

Chronotropic Incompetence and Dynamic Postexercise Autonomic Dysfunction Are Associated with the Presence and Severity of Erectile Dysfunction

BACKGROUND

Exercise stress testing (EST) is crucial to determine cardiovascular (CV) risk in men with erectile dysfunction (ED). Low exercise workload, a slower rate of recovery following exercise, and an impaired capacity to increase heart rate (HR) during exercise testing (chronotropic incompetence) are independent predictors of adverse CV outcomes. Aim of this study was to investigate the association between ED and EST parameters.

METHODS

A total of 180 ED patients and 50 men without ED underwent maximal EST. Exercise parameters including exercise capacity (metabolic equivalents, METS), peak exercise time, HR at six METS, peak exercise, HR recovery (HRR) at 1 and 2 minutes and chronotropic index (CI) were evaluated in all individuals. Endothelial function was evaluated with flow-mediated dilatation (FMD) of the brachial artery.

RESULTS

ED patients had lower peak exercise time and thus lower calculated exercise capacity (P < 0.001) and reduced CI (P < 0.01) compared to men without ED. There was a significant association of ED severity with duration of exercise, peak workload, HRR 2 minutes after exercise, and CI (all P < 0.05). There also was a positive relation of HRR and CI with FMD (all P < 0.05).

CONCLUSIONS

This study shows interrelationships between exercise capacity, HRR, CI, and ED. Abnormal HRR and CI are associated with systemic endothelial dysfunction. These findings imply pathophysiological links and may have important implications for the estimation of cardiovascular risk in ED patients.

Aerobic exercise effect on prognostic markers for systolic heart failure patients: a systematic review and meta-analysis

From previous systematic reviews and meta-analyses, there is consensus about the positive effect of exercise training on exercise capacity for systolic heart failure (HF); however, the effect on actual prognostic markers such as NTproBNP and minute ventilation/carbon dioxide production (VE/VCO2) slope has not been evaluated. The primary aim of the proposed study is to determine the effect of aerobic exercise training (AEX) on the VE/VCO2 slope and NTproBNP. The following databases (up to February 30, 2013) were searched with no language limitations: CENTRAL (The Cochrane Library 2013, issue 2), MEDLINE (from January 1966), EMBASE (from January 1980), and Physiotherapy Evidence Database (PEDro) (from January 1929). We screened reference lists of articles and also conducted an extensive hand search of the literature. Randomized controlled trials of exercise-based interventions with 2-month follow-up or longer compared to usual medical care or placebo were included. The study population comprised adults aged between 18 and 65 years, with evidence of chronic systolic heart failure (LVEF < 45 % and baseline NTproBNP > 300 pg/ml). Two review authors independently extracted data on study design, participants, interventions, and outcomes. We assessed the risk of bias using PEDro scale. We calculated mean differences (MD) or standardized mean differences between intervention and control groups for outcomes with sufficient data; for other outcomes, we described findings from individual studies. Eight studies involving a total of 408 participants met the inclusion criteria across the NTproBNP (5 studies with 191 patients) and VE/VCO2 slope (4 studies with 217 patients). Aerobic exercise significantly improved NTproBNP by a MD of -817.75 [95 % confidence interval (CI) -929.31 to -706.19]. Mean differences across VE/VCO2 slope were -6.55 (95 % CI -7.24 to -5.87). Those patients' characteristics and exercise were similar (frequency = 3-5 times/week; duration = 20-50 min/day; intensity = 60-80 % of VO2 peak) on the included studies. Moreover, the risk of bias across all studies was homogeneous (PEDro scale = 7-8 points). However, based on the statistical analysis, the heterogeneity among the studies was still high, which is related to the variable characteristics of the studies. Aerobic exercise may be effective at improving NTproBNP and the VE/VCO2 slope in systolic HF patients, but these effects are limited to a specific HF population meeting specific inclusion criterion in a limited number of studies. Future randomized controlled studies including diastolic and HF overleap with pulmonary diseases are needed to better understand the exact influence of AEX.

Aerobic interval training vs. moderate continuous training in coronary artery disease patients: a systematic review and meta-analysis

BACKGROUND

Exercise training improves exercise capacity (peakVO2), which is closely related to long-term survival in cardiac patients. However, it remains unclear which type and intensity of exercise is most effective for improving exercise tolerance and body weight. Individual studies suggest that aerobic interval training (AIT) might increase peakVO2 more in this population.

OBJECTIVE

We conducted a meta-analysis to summarize the effects of AIT compared with moderate continuous training (MCT) on peakVO2, submaximal exercise capacity, and body weight in patients with coronary artery disease (CAD) with preserved and/or reduced left ventricular ejection fraction (LVEF).

DATA SOURCES AND STUDY SELECTION

A systematic search was conducted and we included randomized trials comparing AIT and MCT in CAD patients lasting at least 4 weeks, reporting peakVO2 results, and published in a peer-reviewed journal up to May 2013. The primary outcome measure was peakVO2. Secondary outcomes were submaximal exercise capacity parameters and body weight.

SYNTHESIS METHODS

Random- and fixed-effects models were used and data were reported as weighted means and 95% confidence intervals (CIs).

RESULTS

Nine study groups were included, involving 206 patients (100 AIT, 106 MCT). Overall, AIT resulted in a significantly larger increase in peakVO2 [+1.60 mL/kg/min (95% CI 0.18-3.02; p = 0.03)] compared with MCT. MCT seemed to be more effective in reducing body weight (-0.78 kg; 95% CI -0.01 to 1.58; p = 0.05).

LIMITATIONS

The small number of studies might have affected the power to reach significance for the secondary outcomes.

CONCLUSION

In CAD patients with preserved and/or reduced LVEF, AIT is superior to MCT for improving peakVO2, while MCT seems to be more effective in reducing body weight. However, large, well-designed, randomized controlled trials are warranted to confirm these findings.

Beneficial effects of combined exercise training on early recovery cardiopulmonary exercise testing indices in patients with chronic heart failure

PURPOSE

Exercise training induces several beneficial effects in patients with chronic heart failure (CHF). This study investigated the effects of high-intensity aerobic interval training (AIT) compared with combined AIT and strength training (COM) on early ventilatory and metabolic recovery pattern after symptom-limited cardiopulmonary exercise testing (CPET) in CHF patients.

METHODS

Stable CHF patients (N = 42; 54 ± 10 years [mean ± SD], 35 males) participated in an exercise training program for 12 weeks, 3 times per week. Participants were randomly assigned to either AIT (n = 20) or COM group (n = 22). Cardiopulmonary exercise testing was performed before and after completion of the program. Primary measurements included absolute and percentage difference of oxygen uptake, carbon dioxide output, minute ventilation ((Equation is included in full-text article.)E), tidal volume (VT), respiratory rate, and the first-degree slope of oxygen uptake ((Equation is included in full-text article.)O2/t slope) and carbon dioxide output ((Equation is included in full-text article.)CO2/t slope) during the first minute of recovery after maximal exercise.

RESULTS

The COM group had a greater improvement in the absolute and the percentage difference of (Equation is included in full-text article.)E (P = .03 and P = .04, respectively) and respiratory rate (P = .02 and P = .01, respectively) during the first minute of recovery period after exercise compared with the AIT group alone. No significant changes were noted for VT measurements. A significant increase in (Equation is included in full-text article.)CO2/t slope was observed in COM compared with the AIT group (P = .01). There was a trend for a greater increase in (Equation is included in full-text article.)O2/t slope in the COM group (P = .07).

CONCLUSIONS

The addition of strength training to AIT induces significant beneficial effects in terms of ventilatory and metabolic recovery kinetics than AIT alone in CHF patients, possibly indicating greater ventilatory efficiency and metabolic improvement.

Benefits of exercise training and the correlation between aerobic capacity and functional outcomes and quality of life in elderly patients with coronary artery disease

Cardiopulmonary exercise training is beneficial to people with coronary artery disease (CAD). Nevertheless, the correlation between aerobic capacity, and functional mobility and quality of life in elderly CAD patients is less addressed. The purpose of the current study is to investigate the beneficial effects of exercise training in elderly people with CAD, integrating exercise stress testing, functional mobility, handgrip strength, and health-related quality of life. Elderly people with CAD were enrolled from the outpatient clinic of a cardiac rehabilitation unit in a medical center. Participants were assigned to the exercise training group (N = 21) or the usual care group (N = 15). A total of 36 sessions of exercise training, completed in 12 weeks, was prescribed. Echocardiography, exercise stress testing, the 6-minute walking test, Timed Up and Go test, and handgrip strength testing were performed, and the Short-Form 36 questionnaire (SF-36) was administered at baseline and at 12-week follow-up. Peak oxygen consumption improved significantly after training. The heart rate recovery improved from 13.90/minute to 16.62/minute after exercise training. Functional mobility and handgrip strength also improved after training. Significant improvements were found in SF-36 physical function, social function, role limitation due to emotional problems, and mental health domains. A significant correlation between dynamic cardiopulmonary exercise testing parameters, the 6-minute walking test, Timed Up and Go test, handgrip strength, and SF-36 physical function and general health domains was also detected. Twelve-week, 36-session exercise training, including moderate-intensity cardiopulmonary exercise training, strengthening exercise, and balance training, is beneficial to elderly patients with CAD, and cardiopulmonary exercise testing parameters correlate well with balance and quality of life.

Effects of interval and continuous exercise training on autonomic cardiac function in COPD patients

BACKGROUND AND AIM

Both interval (IT) and continuous (CT) exercise training results in an improvement of aerobic capacity in patients with chronic obstructive pulmonary disease (COPD); however, their effects on cardiac autonomic function remains unclear. The aim of our study was to evaluate the effect of a supervised CT vs IT on autonomic cardiac function in COPD patients.

METHODS

COPD patients were divided into two different groups according to training modality (IT or CT). Autonomic cardiac dysfunction (ACD) was defined as a heart rate recovery lower than 12 bpm heart rate after the first minute of maximal exercise (HRR1 ) and an abnormal chronotropic response (CR) to exercise (<80%).

RESULTS

A total of 29 patients {mean [standard deviation (SD)] age: 68 (8) years, %FEV1 : 42 (13) predicted} were trained (15 subjects in the CT group, 14 subjects in the IT group). After training, both groups increased peak oxygen consumption [mean difference ΔVO2 peak: 156 mL/min (P = 0.04) on IT; and 210 mL/min (P = 0.01) on CT], HRR1 [IT, from 10.4 (5) to 13.8 (5) bpm (P = 0.04); and CT, from 14.3 (5) to 17.7 (5) bpm (P = 0.04)] and CR [IT, from 57% (22) to 81% (9) (P = 0.001); and CT, from 48% (28) to 73% (17) (P = 0.001)]. Sixteen patients showed ACD. Among these patients, HRR1 (P = 0.01 for IT and P = 0.04 for CT) and CR (P = 0.001 for IT and P = 0.002 for CT) were enhanced after training.

CONCLUSIONS

Both IT and CT exercise training improve heart rate recovery and CR in COPD patients. These benefits could help to individualize exercise training.

Exercise intolerance in chronic heart failure: the role of cortisol and the catabolic state

Chronic heart failure (CHF) is a complex clinical syndrome leading to exercise intolerance due to muscular fatigue and dyspnea. Hemodynamics fail to explain the reduced exercise capacity, while a significant skeletal muscular pathology seems to constitute the main underlying mechanism for exercise intolerance in CHF patients. There have been proposed several metabolic, neurohormonal and immune system abnormalities leading to an anabolic/catabolic imbalance that plays a central role in the pathogenesis of the wasting process of skeletal muscle myopathy. The impairment of the anabolic axes is associated with the severity of symptoms and the poor outcome in CHF, whereas increased cortisol levels are predictive of exercise intolerance, ventilatory inefficiency and chronotropic incompetence, suggesting a significant contributing mechanism to the limited functional status. Exercise training and device therapy could have beneficial effects in preventing and treating muscle wasting in CHF. However, specific anabolic treatment needs more investigation to prove possible beneficial effects.

High-intensity aerobic interval exercise in chronic heart failure

Aerobic exercise training is strongly recommended in patients with heart failure (HF) and reduced left ventricular ejection fraction (LVEF) to improve symptoms and quality of life. Moderate-intensity aerobic continuous exercise (MICE) is the best established training modality in HF patients. For about a decade, however, another training modality, high-intensity aerobic interval exercise (HIIE), has aroused considerable interest in cardiac rehabilitation. Originally used by athletes, HIIE consists of repeated bouts of high-intensity exercise interspersed with recovery periods. The rationale for its use is to increase exercise time spent in high-intensity zones, thereby increasing the training stimulus. Several studies have demonstrated that HIIE is more effective than MICE, notably for improving exercise capacity in patients with HF. The aim of the present review is to describe the general principles of HIIE prescription, the acute physiological effects, the longer-term training effects, and finally the future perspectives of HIIE in patients with HF.

Should high-intensity-aerobic interval training become the clinical standard in heart failure?

Aerobic exercise training in the heart failure (HF) population is supported by an extensive body of literature. The clinically accepted model for exercise prescription is currently moderate-intensity-aerobic continuous training (MI-ACT). Documented benefits from the literature include improvements in various aspects of physiologic function, aerobic exercise capacity and quality of life while the impact on morbidity and mortality is promising but requires further investigation. Recently, however, a body of evidence has begun to emerge demonstrating high-intensity-aerobic interval training (HI-AIT) can be performed safely with impressive improvements in physiology, functional capacity and quality of life. These initial findings have led some to question the long-standing clinical approach to aerobic exercise training in patients with HF (i.e., MI-ACT), implying it should perhaps be replaced with a HI-AIT model. This is a potentially controversial paradigm shift given the potential increase in adverse event risk associated with exercising at higher intensities, particularly in the HF population where the likelihood of an untoward episode is already at a heightened state relative to the apparently healthy population. The present review therefore addresses key issues related to HI-AIT in the HF population and makes recommendations for future research and current clinical practice.

Meta-analysis of aerobic interval training on exercise capacity and systolic function in patients with heart failure and reduced ejection fractions

It is unknown if vigorous to maximal aerobic interval training (INT) is more effective than traditionally prescribed moderate-intensity continuous aerobic training (MCT) for improving peak oxygen uptake (Vo2) and the left ventricular ejection fraction (LVEF) in patients with heart failure with reduced ejection fraction. MEDLINE, PubMed, Scopus, and the Web of Science were searched using the following keywords: "heart failure," high-intensity interval exercise," "high-intensity interval training," "aerobic interval training," and "high-intensity aerobic interval training." Seven randomized trials were identified comparing the effects of INT and MCT on peak Vo2, 5 of which measured the LVEF at rest. The trials included clinically stable patients with heart failure with reduced ejection fraction with impaired left ventricular systolic function (mean LVEF 32%) who were relatively young (mean age 61 years) and predominantly men (82%). Weighted mean differences were calculated using a random-effects model. INT led to significantly higher increases in peak Vo2 compared with MCT (INT vs MCT, weighted mean difference 2.14 ml O2/kg/min, 95% confidence interval 0.66 to 3.63). Comparison of the effects of INT and MCT on the LVEF at rest was inconclusive (INT vs MCT, weighted mean difference 3.29%, 95% confidence interval -0.7% to 7.28%). In conclusion, in clinically stable patients with heart failure with reduced ejection fraction, INT is more effective than MCT for improving peak Vo2 but not the LVEF at rest.

Sleep apnea and cognitive function in heart failure

Background. Prior research indicates that heart failure (HF) patients exhibit significant cognitive deficits on neuropsychological testing. Sleep apnea is associated with both HF and reduced cognitive function, but the combined impact of these conditions on cognitive function is unknown. Methods. In the current study, 172 older adults with a dual diagnosis of HF and sleep apnea or HF alone completed a battery of cognitive tests measuring attention, executive functioning, and memory. Results. Relative to patients with HF alone, persons with both HF and sleep apnea performed worse on measures of attention after adjusting for demographic and medical variables. Conclusions. The current findings suggest that HF patients with comorbid sleep apnea may be at greater risk for cognitive impairment relative to HF patient without such history. Further work is needed to clarify mechanisms for these findings and to determine whether the interactive effects on cognitive function lead to poorer patient outcomes.

Heart rate recovery: a practical clinical indicator of abnormal cardiac autonomic function

The autonomic nervous system (ANS) and cardiovascular function are intricately and closely related. One of the most frequently used diagnostic and prognostic tools for evaluating cardiovascular function is the exercise stress test. Exercise is associated with increased sympathetic and decreased parasympathetic activity and the period of recovery after maximum exercise is characterized by a combination of sympathetic withdrawal and parasympathetic reactivation, which are the two main arms of the ANS. Heart rate recovery after graded exercise is one of the commonly used techniques that reflects autonomic activity and predicts cardiovascular events and mortality, not only in cardiovascular system disorders, but also in various systemic disorders. In this article, the definition, applications and protocols of heart rate recovery and its value in various diseases, in addition to exercise physiology, the ANS and their relationship, will be discussed.

Chronotropic incompetence and abnormal heart rate recovery early after left ventricular assist device implantation

BACKGROUND

Chronotropic response to exercise and heart rate recovery immediately after exercise (HRR(1) ) are valid prognostic markers in patients with chronic heart failure (CHF). The aim of this study was to evaluate heart rate profile during and after exercise in CHF patients early after left ventricular assist device (LVAD) implantation.

METHODS

We enrolled seven stable consecutive CHF patients (five males, mean age: 45 ± 16 years) after 1 month of LVAD (HeartMate II; Thoratec Corp, Pleasanton, CA, USA) implantation, seven healthy subjects, and 14 patients with advanced HF (HF control group) who performed an incremental symptom-limited cardiopulmonary exercise testing (CPET). CHF patients performed CPET at 1 and 3 months after LVAD. HRR(1) was defined as the HR difference from peak to 1 minute after exercise and chronotropic response to exercise as the chronotropic reserve ([CR, %]=[peak HR-resting HR/220-age-resting HR]× 100).

RESULTS

LVAD patients 3 months after implantation had a significantly different HR profile during exercise compared to healthy controls, with significantly lower CR (57 ± 31 vs 90 ± 14, %, P < 0.001) and HRR(1) (14 ± 6 vs 28 ± 8, bpm, P < 0.01). HR profile during exercise did not significantly change 1 and 3 months after LVAD implantation. There was no statistical difference compared to HF control group and LVAD group regarding cardiopulmonary parameters.

CONCLUSIONS

LVAD patients present an impaired CR and an abnormal HRR(1) after implantation, indicating significant cardiac autonomic abnormalities. These alterations seem to remain unaltered 3 months after LVAD implantation.

Skeletal muscle microcirculatory abnormalities are associated with exercise intolerance, ventilatory inefficiency, and impaired autonomic control in heart failure

BACKGROUND

Several skeletal muscle abnormalities have been identified in patients with chronic heart failure (CHF), including endothelial dysfunction. We hypothesized that skeletal muscle microcirculation, assessed by near-infrared spectroscopy (NIRS), is impaired in CHF patients and is associated with disease severity.

METHODS

Eighty-three stable patients with mild-moderate CHF (72 males, mean age 54 ± 14 years, body mass index 26.7 ± 3.4 kg/m(2)) and 8 healthy subjects, matched for age, gender and body mass index, underwent NIRS with the vascular occlusion technique and cardiopulmonary exercise testing (CPET) evaluation on the same day. Tissue oxygen saturation (StO(2), %), defined as the percentage of hemoglobin saturation in the microvasculature compartments, was measured in the thenar muscle by NIRS before, during and after 3-minute occlusion of the brachial artery. Measurements included StO(2), oxygen consumption rate (OCR, %/min) and reperfusion rate (RR, %/min). All subjects underwent a symptom-limited CPET on a cycle ergometer. Measurements included VO(2) at peak exercise (VO(2)peak, ml/kg/min) and anaerobic threshold (VO(2)AT, ml/kg/min), VE/VCO(2) slope, chronotropic reserve (CR, %) and heart rate recovery (HRR(1), bpm).

RESULTS

CHF patients had significantly lower StO(2) (75 ± 8.2 vs 80.3 ± 6, p < 0.05), lower OCR (32.3 ± 10.4 vs 37.7 ± 5.5, p < 0.05) and lower RR (10 ± 2.8 vs 15.7 ± 6.3, p < 0.05) compared with healthy controls. CHF patients with RR ≥9.5 had a significantly greater VO(2)peak (p < 0.001), VO(2)AT (p < 0.01), CR (p = 0.01) and HRR(1) (p = 0.01), and lower VE/VCO(2) slope (p = 0.001), compared to those with RR <9.5. In a multivariate analysis, RR was identified as an independent predictor of VO(2)peak, VE/VCO(2) slope and HRR(1).

CONCLUSIONS

Peripheral muscle microcirculation, as assessed by NIRS, is significantly impaired in CHF patients and is associated with disease severity.

High-intensity interval exercise in chronic heart failure: protocol optimization

BACKGROUND

There are little data on the optimization of high-intensity aerobic interval exercise (HIIE) protocols in patients with chronic heart failure (CHF). Therefore, we compared acute cardiopulmonary responses to 4 different HIIE protocols to identify the optimal one.

METHODS AND RESULTS

Twenty men with stable systolic CHF performed 4 different randomly ordered single HIIE sessions with measurement of gas exchange. For all protocols (A, B, C, and D) exercise intensity was set at 100% of peak power output (PPO). Interval duration was 30 seconds (A and B) or 90 seconds (C and D), and recovery was passive (A and C) or active (50% of PPO in B and D). Time spent above 85% of VO(2peak) and time above the ventilatory threshold were similar across all 4 HIIE protocols. Total exercise time was significantly longer in protocols with passive recovery intervals (A: 1,651 ± 347 s; C: 1,574 ± 382 s) compared with protocols with active recovery intervals (B: 986 ± 542 s; D: 961 ± 556 s). All protocols appeared to be safe, with exercise tolerance being superior during protocol A.

CONCLUSION

Among the 4 HIIE protocols tested, protocol A with short intervals and passive recovery appeared to be superior.

Intermittent versus continuous exercise training in chronic heart failure: a meta-analysis

INTRODUCTION

We conducted a meta-analysis of randomized, controlled trials of combined strength and intermittent aerobic training, intermittent aerobic training only and continuous exercise training in heart failure patients.

METHODS

A systematic search was conducted of Medline (Ovid) (1950-September 2011), Embase.com (1974-September 2011), Cochrane Central Register of Controlled Trials and CINAHL (1981-September 19 2011). The search strategy included a mix of MeSH and free text terms for the key concepts heart failure, exercise training, interval training and intermittent exercise training.

RESULTS

The included studies contained an aggregate of 446 patients, 212 completed intermittent exercise training, 66 only continuous exercise training, 59 completed combined intermittent and strength training and 109 sedentary controls. Weighted mean difference (MD) in Peak VO2 was 1.04mlkg(-1)min(-1) and (95% C.I.) was 0.42-1.66 (p=0.0009) in intermittent versus continuous exercise training respectively. Weighted mean difference in Peak VO2 was -1.10mlkg(-1)min(-1) (95% C.I.) was -1.83-0.37 p=0.003 for intermittent only versus intermittent and strength (combined) training respectively. In studies reporting VE/VCO2 for intermittent versus control groups, MD was -1.50 [(95% C.I. -2.64, -0.37), p=0.01] and for intermittent versus continuous exercise training MD was -1.35 [(95% C.I. -2.15, -0.55), p=0.001]. Change in peak VO2 was positively correlated with weekly exercise energy expenditure for intermittent exercise groups (r=0.48, p=0.05).

CONCLUSIONS

Combined strength and intermittent exercise appears superior for peak VO2 changes when compared to intermittent exercise of similar exercise energy expenditure.

Effects of interval cycle training with or without strength training on vascular reactivity in heart failure patients

BACKGROUND

Exercise training confers beneficial effects on vascular reactivity in patients with chronic heart failure (CHF). This randomized study compares the effects of interval cycle training combined with strength training versus interval training alone on vascular reactivity in CHF patients.

METHODS

Twenty-eight consecutive stable CHF patients (23 males, 53 ± 10 years, 28.4 ± 4.1 kg/m(2), left ventricular ejection fraction of 37 ± 12%) were randomly assigned to 3 times' weekly training sessions for 3 months, consisting of a) 40 minutes of interval cycle training (n = 14), versus b) 20 minutes of similar interval training plus 20 minutes of strength training of the quadriceps, hamstrings, muscles of the shoulder and biceps brachialis (n = 14). The work/recovery ratio of each session was 30/60 seconds. The intensity of interval training was set at 50% of the peak workload achieved at the steep ramp test (consisted of a 25-Watt increase on a cycle ergometer every 10 seconds until exhaustion). All patients underwent maximal, symptom-limited cardiopulmonary exercise testing and ultrasound evaluation of vascular reactivity by flow-mediated vasodilation (FMD) before and after the program.

RESULTS

A significant improvement in FMD was observed in the combined training group (P = 0.002), in contrast to the interval training alone group (P = NS); the improvement was significantly greater in the combined training than in the interval training alone group (P < .05). Peak oxygen uptake increased significantly and similarly in both groups, in the interval training group (P = .03), and in the combined training group (P = .006). No significant correlation was found between FMD improvement and cardiopulmonary exercise parameters.

CONCLUSIONS

A combined high-intensity, interval cycle exercise with strength training induces a greater beneficial effect on vascular reactivity rather than interval exercise training alone in CHF patients.

The addition of strength training to aerobic interval training: effects on muscle strength and body composition in CHF patients

PURPOSE

The loss of lean muscle mass and muscle strength is a common problem in chronic heart failure (CHF) patients. Endurance training is efficient in improving patient exercise capacity. This study sought to evaluate the additional effects of strength training on muscle strength and body composition in chf patients participating in an interval training program.

METHODS

Twenty consecutive, stable CHF patients participated in a rehabilitation program. Subjects were randomly assigned to aerobic (n = 10) or combined aerobic plus strength training group (n = 10). Aerobic group performed interval training on cycle ergometers. Strength training incorporated exercises for various muscle groups, including quadriceps, hamstrings, biceps brachii, and the deltoids. Both regimes were of the same duration. Body composition was evaluated by whole-body dual energy x-ray absorptiometry and quadriceps strength by the sum of the 2-repetition maximum (2-RM) test for each leg. Peak oxygen uptake (.VO(2peak)) and peak work load (W(peak)) as well as oxygen uptake (.VO(2AT)) and workload at anaerobic threshold (W(AT)) were evaluated by a symptom limited cardiopulmonary exercise testing.

RESULTS

Concerning leg lean mass, no significant within-subjects or between-groups changes were observed (P > .05). Both groups improved in 2-RM test (P < .05), while a significant difference was observed between groups (P < .05). .VO(2peak) and .VO(2AT) and W(peak) and W(AT) were equally improved between training groups (P < .05).

CONCLUSIONS

Combined aerobic interval and strength training induces a greater benefit than interval training alone on muscle strength in CHF patients. Adaptations other than hypertrophy, such as muscle fiber type alterations and/or neuromuscular adjustments, may account for these results.

Effects of interval exercise training on respiratory drive in patients with chronic heart failure

BACKGROUND

Patients with chronic heart failure (CHF) suffer from ventilatory abnormalities. This study examined the effects of interval exercise training on the respiratory drive in CHF patients.

METHODS

Forty-six clinically stable CHF patients (38 males/8 women, mean age = 53 +/- 11 years) participated in an exercise rehabilitation program (ERP) 3 times/week, for 12 weeks by interval training modality with or without the addition of resistance training. All patients underwent symptom-limited cardiopulmonary exercise testing (CPET), and measurements of mouth occlusion pressure at 100 ms (P(0.1)) and maximum inspiratory muscle strength (P(Imax)) before and after ERP. Respiratory drive was estimated by mouth occlusion pressure P(0.1) and P(0.1)/P(Imax) ratio at rest, and the ventilatory pattern by resting mean inspiratory flow (V(T)/T(I)) and by V(T)/T(I) at identical CPET workloads, before and after ERP. We also studied a control non exercising group of 11 patients (8 men and 3 women).

RESULTS

P(0.1) at rest decreased from 3.04 +/- 1.52 to 2.62 +/- 0.9 cmH(2)O (p = 0.015), P(0.1)/P(Imax) % at rest from 4.56 +/- 3.73 to 3.69 +/- 2.03 (p = 0.006), resting V(T)/T(I) from 0.44 +/- 0.10 to 0.41 +/- 0.10 l/s (p = 0.014), and V(T)/T(I) at identical work rate from 2.13 +/- 0.59 to 1.93 +/- 0.58 l/s (p = 0.001) after ERP. VO(2) at peak exercise increased from 16.3 +/- 4.8 to 18.5 +/- 5.3 ml/kg/min (p < 0.001) in the exercise group. No improvement was noted in the control group.

CONCLUSIONS

ERP by interval training improves the respiratory drive and ventilatory pattern at rest and during exercise in CHF patients.

Relation of heart rate recovery to psychological distress and quality of life in patients with chronic heart failure

BACKGROUND

Psychological distress, poor disease-specific quality of life (QoL), and reduction in vagally mediated early heart rate recovery (HRR) after exercise, all previously predicted morbidity and mortality in patients with chronic heart failure (CHF). We hypothesized lower HRR with greater psychological distress and poorer QoL in CHF.

DESIGN

All assessments were made at the beginning of a comprehensive cardiac outpatient rehabilitation intervention program.

METHODS

Fifty-six CHF patients (mean 58+/-12 years, 84% men) completed the Hospital Anxiety and Depression Scale and the Minnesota Living With Heart Failure Questionnaire. HRR was determined as the difference between HR at the end of exercise and 1 min after exercise termination (HRR-1).

RESULTS

Elevated levels of anxiety symptoms (P=0.005) as well as decreased levels of the Minnesota Living With Heart Failure Questionnaire total (P = 0.025), physical (P=0.026), and emotional (P=0.017) QoL were independently associated with blunted HRR-1. Anxiety, total, physical, and emotional QoL explained 11.4, 8, 7.8, and 9.0%, respectively, of the variance after controlling for covariates. Depressed mood was not associated with HRR-1 (P=0.20).

CONCLUSION

Increased psychological distress with regard to elevated anxiety symptoms and impaired QoL were independent correlates of reduced HRR-1 in patients with CHF. Reduced vagal tone might explain part of the adverse clinical outcome previously observed in CHF patients in relation to psychological distress and poor disease-specific QoL.