Objective effects of a 6 months' endurance and strength training program in outpatients with congestive heart failure

Muscle-Skeletal Abnormalities and Muscle Oxygenation during Isokinetic Strength Exercise in Heart Failure with Preserved Ejection Fraction Phenotype: A Cross-Sectional Study

Exercise intolerance, a hallmark of patients with heart failure (HF), is associated with muscle weakness. However, its causative microcirculatory and muscle characteristics among those with preserved or reduced ejection fraction (HFpEF or HFrEF) phenotype is unclear. The musculoskeletal abnormalities that could result in impaired peripheral microcirculation are sarcopenia and muscle strength reduction in HF, implying lowered oxidative capacity and perfusion affect transport and oxygen utilization during exercise, an essential task from the microvascular muscle function. Besides that, skeletal muscle microcirculatory abnormalities have also been associated with exercise intolerance in HF patients who also present skeletal muscle myopathy. This cross-sectional study aimed to compare the muscle microcirculation dynamics via near-infrared spectroscopy (NIRS) response during an isokinetic muscle strength test and ultrasound-derived parameters (echo intensity was rectus femoris muscle, while the muscle thickness parameter was measured on rectus femoris and quadriceps femoris) in heart failure patients with HFpEF and HFrEF phenotypes and different functional severities (Weber Class A, B, and C). Twenty-eight aged-matched patients with HFpEF (n = 16) and HFrEF (n = 12) were assessed. We found phenotype differences among those with Weber C severity, with HFrEF patients reaching lower oxyhemoglobin (O₂Hb, μM) (−10.9 ± 3.8 vs. −23.7 ± 5.7, p = 0.029) during exercise, while HFpEF reached lower O₂Hb during the recovery period (−3.0 ± 3.4 vs. 5.9 ± 2.8, p = 0.007). HFpEF with Weber Class C also presented a higher echo intensity than HFrEF patients (29.7 ± 8.4 vs. 15.1 ± 6.8, p = 0.017) among the ultrasound-derived variables. Our preliminary study revealed more pronounced impairments in local microcirculatory dynamics in HFpEF vs. HFrEF patients during a muscle strength exercise, combined with muscle-skeletal abnormalities detected via ultrasound imaging, which may help explain the commonly observed exercise intolerance in HFpEF patients.

Lean Mass Abnormalities in Heart Failure: The Role of Sarcopenia, Sarcopenic Obesity, and Cachexia

The role of body composition in patients with heart failure (HF) has been receiving much attention in the last few years. Particularly, reduced lean mass (LM), the best surrogate for skeletal muscle mass, is independently associated with abnormal cardiorespiratory fitness (CRF) and muscle strength, ultimately leading to reduced quality of life and worse prognosis. While in the past, reduced CRF in patients with HF was thought to result exclusively from cardiac dysfunction leading to reduced cardiac output at peak exercise, current evidence supports the concept that abnormalities in LM may also play a critical role. Abnormalities in the LM body composition compartment are associated with the development of sarcopenia, sarcopenic obesity, and cachexia. Such conditions have been implicated in the pathophysiology and progression of HF. However, identification of such conditions remains challenging, as universal definitions for sarcopenia, sarcopenic obesity, and cachexia are lacking. In this review article, we describe the most common body composition abnormalities related to the LM compartment, including skeletal and respiratory muscle mass abnormalities, and the consequences of such anomalies on CRF and muscle strength in patients with HF. Finally, we discuss the potential nonpharmacologic therapeutic strategies such as exercise training (ie, aerobic exercise and resistance exercise) and dietary interventions (ie, dietary supplementation and dietary patterns) that have been implemented to target body composition, with a focus on HF.

Determinants of maximal exercise performance in chronic heart failure

BACKGROUND

Chronic heart failure (CHF) is characterized by symptoms like fatigue, dyspnoea and limited exercise performance. It has been postulated that maximal exercise performance (Wmax) is predominantly limited by skeletal muscle function and less by heart function.

AIM

To study the interrelation between most relevant muscle and anthropometrical variables and Wmax in CHF patients in order to develop a model that describes the impact of these variables for maximal exercise performance.

DESIGN

In 77 patients with CHF Wmax was assessed by incremental cycle ergometry until exhaustion (20 Watt/3 min). Peak torque (strength) and total work (endurance) for the quadriceps and hamstrings were assessed by isokinetic dynamometry. Isometric strength was measured by hand dynamometry. Relevant muscle areas were calculated by computerized tomography scan.

RESULTS

Significant correlations between Wmax and isokinetic muscle parameters (peak torque and total work) ranged from 0.41-0.65 (P<0.01). Other significant relationships (P<0.01) with Wmax were obtained for age (r=-0.22), gender (r=0.45), fat free mass (FFM) (r=0.51), quadriceps muscle area (r=0.73), hamstrings muscle area (r=0.50), upper leg muscle function (i.e., a combination of muscle strength and muscle endurance) (r=0.71) and isometric strength (r=0.63). Multiple regression analysis showed that upper leg muscle function and quadriceps muscle area could predict 57% of the variance in Wmax.

CONCLUSION

Muscle strength and muscle endurance, combined with quadriceps muscle area are the main predictors of maximal exercise performance in patients with CHF.

Recommendations for resistance exercise in cardiac rehabilitation. Recommendations of the German Federation for Cardiovascular Prevention and Rehabilitation

Aerobic endurance training has been an integral component of the international recommendations for cardiac rehabilitation for more than 30 years. Notwithstanding, only in recent years have recommendations for a dynamic resistance-training program been cautiously put forward. The perceived increased risk of cardiovascular complications related to blood pressure elevations are the primary concern with resistance training in cardiac patients; recent studies however have demonstrated that this need not be a contraindication in all cardiac patients. While blood pressure certainly may rise excessively during resistance training, the actual rise depends on a variety of controllable factors including magnitude of the isometric component, the load intensity, the amount of muscle mass involved as well as the number of repetitions and/or the load duration. Intra-arterial blood pressure measurements in cardiac patients have demonstrated that that during low-intensity resistance training [40-60% maximum voluntary contraction (MVC)] with 15-20 repetitions, only modest elevations in blood pressure are revealed, similar to those seen during moderate endurance training. When properly implemented by an experienced exercise therapist, in specific patient groups an individually tailored, medically supervised dynamic resistance training program carries no inherent higher risk for the patient than aerobic endurance training. As an adjunct to endurance training, in selected patients, resistance training can increase muscle strength and endurance, as well as positively influence cardiovascular risk factors, metabolism, cardiovascular function, psychosocial well-being and quality of life. According to present data, resistance training is however not recommended for all patient groups. The appropriate training method and correct performance are highly dependent on each patient's clinical status, cardiac stress tolerance and possible comorbidities. Most studies have used middle-aged men of average normal aerobic performance capacity and with good left-ventricular (LV) function. Data are lacking for high-risk groups, women and older patients. With the current knowledge it is reasonable to include resistance training without any restraints as part of cardiac rehabilitation programs for coronary artery disease (CAD) patients with good cardiac performance capacity (i.e., revascularised and with good myocardial function). As patients with myocardial ischaemia and/or poor left ventricular function may develop wall motion disturbances and/or severe ventricular arrhythmias during resistance exercise, the following criteria are suggested for resistance training: moderate-to-good LV function, good cardiac performance capacity [>5-6 metabolic equivalents of oxygen consumption (METS)=1.4 watt/kg body weight], no symptoms of angina pectoris or ST segment depression under continued maintenance of the medical therapy. Based on available data, this article presents recommendations for risk stratification in cardiac rehabilitation programs with respect to the implementation of dynamic resistance training. Additional recommendations for specific patient groups and detailed directions showing how to structure and implement such therapy programs are presented as well.

Dietary Nitrate and Skeletal Muscle Contractile Function in Heart Failure

Heart failure (HF) patients suffer from exercise intolerance that diminishes their ability to perform normal activities of daily living and hence compromises their quality of life. This is due largely to detrimental changes in skeletal muscle mass, structure, metabolism, and function. This includes an impairment of muscle contractile performance, i.e., a decline in the maximal force, speed, and power of muscle shortening. Although numerous mechanisms underlie this reduction in contractility, one contributing factor may be a decrease in nitric oxide (NO) bioavailability. Consistent with this, recent data demonstrate that acute ingestion of NO3 (-)-rich beetroot juice, a source of NO via the NO synthase-independent enterosalivary pathway, markedly increases maximal muscle speed and power in HF patients. This review discusses the role of muscle contractile dysfunction in the exercise intolerance characteristic of HF, and the evidence that dietary NO3 (-) supplementation may represent a novel and simple therapy for this currently underappreciated problem.

Comparison of Different Forms of Exercise Training in Patients With Cardiac Disease: Where Does High-Intensity Interval Training Fit?

In this review, we discuss the most recent forms of exercise training available to patients with cardiac disease and their comparison or their combination (or both) during short- and long-term (phase II and III) cardiac rehabilitation programs. Exercise training modalities to be discussed include inspiratory muscle training (IMT), resistance training (RT), continuous aerobic exercise training (CAET), and high-intensity interval training (HIIT). Particular emphasis is placed on HIIT compared or combined (or both) with other forms such as CAET or RT. For example, IMT combined with CAET was shown to be superior to CAET alone for improving functional capacity, ventilatory function, and quality of life in patients with chronic heart failure. Similarly, RT combined with CAET was shown to optimize benefits with respect to functional capacity, muscle function, and quality of life. Furthermore, in recent years, HIIT has emerged as an alternative or complementary (or both) exercise modality to CAET, providing equivalent if not superior benefits to conventional continuous aerobic training with respect to aerobic fitness, cardiovascular function, quality of life, efficiency, safety, tolerance, and exercise adherence in both short- and long-term training studies. Finally, short-interval HIIT was shown to be useful in the initiation and improvement phases of cardiac rehabilitation, whereas moderate- or longer-interval (or both) HIIT protocols appear to be more appropriate for the improvement and maintenance phases because of their high physiological stimulus. We now propose progressive models of exercise training (phases II-III) for patients with cardiac disease, including a more appropriate application of HIIT based on the scientific literature in the context of a multimodal cardiac rehabilitation program.

The Impact of Exercise Training on Conduit Artery Wall Thickness and Remodeling in Chronic Heart Failure Patients

Exercise training is an important adjunct to medical therapy in chronic heart failure, but the extent to which exercise impacts on conduit artery remodeling is unknown. The aim of this study was to evaluate the impact of aerobic and resistance exercise training modalities on arterial remodeling in patients with chronic heart failure. We randomized 36 untrained subjects with chronic heart failure to resistance training (58.8±3.5 years), aerobic training (61.3±2.8 years), or an untrained control group (64.4±2.4 years). Peak oxygen consumption during cycle ergometry increased after 12 weeks in both the resistance and aerobic training ( P <0.001) groups, but not in controls, whereas leg strength only increased after resistance training ( P <0.05). Brachial artery wall thickness decreased in the resistance training group (475±10 versus 443±13 μm; P <0.01), whereas no changes were apparent in the aerobic or control groups. Brachial diameter increased by ≈6% and ≈5% in the aerobic training and resistance training groups ( P <0.01), with no change evident in the control group. The wall:lumen ratio consequently declined in the resistance training group at 12 weeks (0.121±0.004 versus 0.107±0.004; P <0.01) and increased in the control group (0.111±0.006 versus 0.121±0.009; P <0.05). No wall:lumen change was evident in the aerobic training group. Our findings suggest that exercise has a systemic impact on remodeling of conduit arteries in humans and that resistance exercise training may be advantageous in subjects with chronic heart failure in this regard.

Effects of low frequency functional electrical stimulation with 15 and 50 Hz on muscle strength in heart failure patients

PURPOSE

To compare the acute effects of functional electrical stimulation (FES) with 15 and 50 Hertz (Hz) frequencies on muscle strength in patients with heart failure with healthy individuals.

METHODS

Twenty-two 61.6 ± 1.0 y-old male volunteers were studied: 10 patients with heart failure (functional class II-III) and 12 healthy controls. The isometric muscle peak torque (IMPT) of the quadriceps femoral muscle was measured through a Biodex dynamometer in maximum voluntary contraction (MVC), and under FES of 50 Hz and 15 Hz, which was applied with a 0.4 ms pulse width, 10-s contraction time, 50-s resting time and maximum tolerable intensity.

RESULTS

The IMPT differed in MVC, 50 Hz and 15 Hz FES both in patients (201.9 ± 14, 55.6 ± 13 and 42.1 ± 12 Newton-metre, respectively; p < 0.001) and in controls (179.3 ± 9, 62.4 ± 8 and 52.3 ± 7 Newton-metre, respectively; p < 0.001). There were no differences between the groups. In patients and controls, respectively, the 50 Hz FES corresponded to 27% versus 35% and the 15 Hz to 21% versus 29% of the IMPT generated at the MVC (p < 0.001).

DISCUSSION

This result can be attributed to the fact that muscle strength is proportional to the stimulation frequency and to the number of recruited motor units. Thus, the higher the frequency, the greater the motor recruiting, producing increased muscle strength.

CONCLUSION

The IMPT generated by acute 50 Hz application of FES is higher than the one generated by 15 Hz, but it is lower than MVC in controls and patients with heart failure.

Effects of aerobic or aerobic and resistance training on cardiorespiratory and skeletal muscle function in heart failure: a randomized controlled pilot trial

OBJECTIVE

To examined the effects of different training modalities on exercise capacity (Vo( 2peak)), systolic function, muscular strength and endurance and quality of life in heart failure patients.

DESIGN

Randomized controlled trial.

SETTING

Cardiac rehabilitation centre in Canada.

SUBJECTS

Forty-two individuals with heart failure (62 +/- 12 years; New York Heart Association (NYHA) classes I-III).

INTERVENTIONS

Aerobic training (n = 14), combined aerobic and resistance training (n = 15) or usual care (n = 13) three times per week for 12 weeks.

MAIN MEASURES

(1) Vo( 2peak) measured by symptom-limited graded exercise test on cycle ergometer; (2) systolic function assessed by two-dimensional echocardiography; (3) muscular strength and muscular endurance measured by one-repetition maximum procedure; and (4) quality of life assessed by questionnaires.

RESULTS

In the intention-to-treat analysis, neither aerobic nor combined aerobic and resistance training significantly improved Vo(2peak), systolic function or quality of life compared with usual care. However, combined aerobic and resistance training significantly improved upper extremity strength (40.7 (14.0)-48.5 (16.0) kg, P<0.05) and muscular endurance (5.7 (2.7)-11.6 (7.6) reps, P<0.05) compared with aerobic training or usual care. In compliant participants (exercise adherence 80%), Vo(2peak) increased in the aerobic group (16.9 (6.0)-19.0 (6.8), P= 0.026) and tended to increase in the combined training group (15.9 (5.0)-17.6 (5.6), P= 0.058) compared with usual care. Quality of life was improved in the aerobic group only.

CONCLUSIONS

Both aerobic and combined aerobic and resistance training are effective interventions to improve Vo(2peak) in compliant heart failure patients. Combined training may be more effective in improving muscle strength and endurance.

Implications of chronic heart failure on peripheral vasculature and skeletal muscle before and after exercise training

The pathophysiology of chronic heart failure (CHF) is typically conceptualized in terms of cardiac dysfunction. However, alterations in peripheral blood flow and intrinsic skeletal muscle properties are also now recognized as mechanisms for exercise intolerance that can be modified by therapeutic exercise. This overview focuses on blood delivery, oxygen extraction and utilization that result from heart failure. Related features of inflammation, changes in skeletal muscle signaling pathways, and vulnerability to skeletal muscle atrophy are discussed. Specific focus is given to the ways in which perfusion and skeletal muscle properties affect exercise intolerance and how peripheral improvements following exercise training increase aerobic capacity. We also identify gaps in the literature that may constitute priorities for further investigation.

Enhancement of isokinetic muscle strength with a combined training programme in chronic heart failure

BACKGROUND

Patients with congestive heart failure (CHF) exhibit an impaired exercised tolerance that dramatically limits their functional capacity and alters their quality of life.

DESIGN

The aim of this study was to compare the effects of two types of training programmes on isokinetic muscle strength and aerobic capacities in patients with CHF.

METHODS

A group of 23 stable CHF patients included consecutively followed an exercise training programme, 3 days a week for 8 weeks. The first group (P1, n=11) exercised on a cycloergometer for 45 min at 65% of peak VO2. The second group (P2, n=12) followed a 45-min combined bicycle and quadricipital strength training. Strength training consisted of 10 series of 10 repetitions at 70% of maximal voluntary force. Incremental maximal cardiopulmonary exercise tests as well as an isokinetic quadricipital dynamometry evaluation were performed before and after training.

RESULTS AND CONCLUSIONS

In P1, peak VO2 increased by 20% (22.3+/-4.9 versus 17.8+/-4.5 ml min(-1) kg(-1); P<0.05) without any significant change in isokinetic muscle strength. In P2, peak VO2 improved within the same range (20.5+/-2.8 versus 18.6+/-3.7 ml min(-1) kg(-1); P<0.01). This last rehabilitation programme significantly increased isokinetic muscle strength at each angular velocities (+10.5+/-13.5%, P<0.04; +5.6+/-7.0%, P<0.03; for 180 degrees s(-1) and 60 degrees s(-1) respectively). Only the combined endurance/strength training programme was associated with an improvement in both peak VO2 and peripheral muscle strength, two significant parameters of outcome and quality of life in CHF.

The isokinetic assessment of peripheral muscle function in patients with coronary artery disease: correlations with cardiorespiratory capacity

OBJECTIVE

We aimed to determine whether diminished cardiorespiratory capacity in patients with coronary artery disease (CAD) is accompanied by impaired skeletal muscle function as measured by isokinetic dynamometry. We also evaluated the correlation between isokinetic strength and aerobic capacity in these patients.

MATERIALS AND METHODS

Fifteen CAD patients and 15 age-matched healthy subjects (mean age 60+/-6 vs. 57+/-3.5 years) underwent maximal laboratory exercise testing, a 6-min walking test and an assessment of peripheral skeletal muscle function by use of an isokinetic apparatus. Quadricep and hamstring function was tested at two angular velocities, 150 and 180 degrees s(-1) with simultaneous electrocardiography monitoring. The cardiorespiratory and mechanical parameters (VO(2), ventilatory threshold [VT], heart rate [HR], and power) were measured at VT and at maximal effort.

RESULTS

Quadricep and hamstring peak torque was impaired in CAD patients, with quadriceps peak torque at 180 degrees being 71.13 +/- 14 vs. 91.13 +/- 23 Nm (P<0.01) and hamstring peak torque 46.50+/-10 vs. 59.86+/-12 Nm (P<0.01). CAD subjects presented a deficient aerobic capacity as compared with the healthy subjects at maximal effort. At VT, the VO(2), ventilation, and HR were significantly lower in CAD patients, at 13.77+/-2.33 vs. 17.08+/-3.59 ml min(-1) kg(-1) (P<0.05), 29.64 +/- 664 vs. 37.76 +/- 7.2 ml min(-1) (P<0.05), and 86+/-14 vs. 111+/-15 beats min(-1) (P=0.001), respectively. The 6-min walking distance was significantly shorter for CAD patients than healthy subjects (425.93+/-52.77 vs. 551.46 +/- 57.94 m; P<0.01). In CAD patients quadriceps and hamstring strength was not correlated with VO(2) at maximal effort and at VT. Total distance walked during the 6-min walk and VO(2)max were correlated (r=0.869; P<0.001) but not at VT.

CONCLUSION

CAD patients showed impaired cardiorespiratory capacity accompanied by increased muscle fatigability as compared with healthy subjects. An isokinetic muscle assessment in these patients must be achieved systematically and seems to have value in cardiovascular rehabilitation.

Safety and Efficacy of Resistance Training in Patients With Chronic Heart Failure: Research‐Based Evidence

Although a rich body of research exists regarding the safety and efficacy of resistance training, health care providers continue to caution patients with heart failure not to engage in this type of exercise. Research studies utilizing resistance training demonstrate improvements in muscular strength and endurance, New York Heart Association functional class, and quality of life. Despite the hemodynamic changes which occur during resistance exercise, no negative outcomes have been reported. The purpose of this paper is to review the most current research regarding the use of resistance training with heart failure patients to provide assistance to clinicians and enable them to provide education and appropriate recommendations to their patients.

Evidence for prescribing exercise as therapy in chronic disease

Considerable knowledge has accumulated in recent decades concerning the significance of physical activity in the treatment of a number of diseases, including diseases that do not primarily manifest as disorders of the locomotive apparatus. In this review we present the evidence for prescribing exercise therapy in the treatment of metabolic syndrome-related disorders (insulin resistance, type 2 diabetes, dyslipidemia, hypertension, obesity), heart and pulmonary diseases (chronic obstructive pulmonary disease, coronary heart disease, chronic heart failure, intermittent claudication), muscle, bone and joint diseases (osteoarthritis, rheumatoid arthritis, osteoporosis, fibromyalgia, chronic fatigue syndrome) and cancer, depression, asthma and type 1 diabetes. For each disease, we review the effect of exercise therapy on disease pathogenesis, on symptoms specific to the diagnosis, on physical fitness or strength and on quality of life. The possible mechanisms of action are briefly examined and the principles for prescribing exercise therapy are discussed, focusing on the type and amount of exercise and possible contraindications.

The effect of resistance training on left ventricular function and structure of patients with chronic heart failure

INTRODUCTION

Resistance training (RT) has been shown to improve chronic heart failure (CHF) patients' functional ability and quality of life. Despite these benefits RT has not always been recommend as a form of exercise principally because of a concern for acceleration of the left ventricular (LV) remodeling process. This study investigated the effects of 8 weeks RT on the LV structure and function of patients with CHF.

METHOD

Fifteen men who suffered from CHF were divided into either a RT program or non-training control group. Before and after 8 weeks of training patients underwent resting echocardiography to assess their end-diastolic and end-systolic dimensions (EDD and ESD, respectively), ejection fraction (EF), fractional shortening (FS) and stroke volume (SV).

RESULTS

A repeated measured ANOVA showed that 8 weeks of RT had no significant effect on the LV measurements (group x time, p>0.05). Post training comparison, however, revealed that the EF and FS of the training group was significantly higher than in the control group (40.9+/-10.5% vs. 30.3+/-4.6%, p=0.029 and 25.0+/-7.0% vs. 17.4+/-3.1%, p=0.020 respectively).

CONCLUSION

RT is a suitable method of training for CHF patients since it does not cause a reduction of LV contractility function or enhance myocardial deterioration as measured by EF and FS.

Reliability of clinical muscular endurance tests in patients with chronic heart failure

BACKGROUND

In clinical praxis it is important to be able to assess the effect of rehabilitation in patients with chronic heart failure (CHF). There is therefore a need for simple clinical tests that are objective, reliable and valid measures.

AIM

The aim of this study was to examine the reliability of three muscle endurance tests for patients with CHF and to compare the results to a healthy control group.

METHOD

The study included 20 patients (7 women) with CHF and 20 healthy persons. Dynamic endurance of the shoulder and calf muscle was measured as well as static shoulder endurance. All three tests were performed twice, within 5-10 days.

RESULTS

The reliability (rs) of the tests for the patients with CHF was between 0.90-0.99 and for the healthy persons between 0.79-0.98. There was also a significant difference in dynamic endurance in shoulder flexion and in heel-rise left leg test between patients with CHF and healthy persons.

CONCLUSION

Tests of dynamic and static endurance of the shoulder muscle and dynamic calf muscle endurance are reliable assessment tools for use in clinical practice. Patients with CHF have reduced isotonic muscular endurance compared with healthy persons.

Resistance Exercise Training in Patients with Heart Failure

The utility, safety and physiological adaptations of resistance exercise training in patients with chronic heart failure (CHF) are reviewed and recommendations based on current research are presented. Patients with CHF have a poor clinical status and impaired exercise capacity due to both cardiac limitations and peripheral maladaptations of the skeletal musculature. Because muscle atrophy has been demonstrated to be a hallmark of CHF, the main principle of exercise programmes in such patients is to train the peripheral muscles effectively without producing great cardiovascular stress. For this reason, new modes of training as well as new training methods have been applied. Dynamic resistance training, based on the principles of interval training, has recently been established as a safe and effective mode of exercise in patients with CHF. Patients perform dynamic strength exercises slowly, on specific machines at an intensity usually in the range of 50-60% of one repetition maximum; work phases are of short duration (< or =60 seconds) and should be followed by an adequate recovery period (work/recovery ratio >1 : 2). Patients with a low cardiac reserve can use small free weights (0.5, 1 or 3 kg), elastic bands with 8-10 repetitions, or they can perform resistance exercises in a segmental fashion. Based on recent scientific evidence, the application of specific resistance exercise programmes is safe and induces significant histochemical, metabolic and functional adaptations in skeletal muscles, contributing to the treatment of muscle weakness and specific myopathy occurring in the majority of CHF patients. Increased exercise tolerance and peak oxygen consumption (V-dotO(2peak)), changes in muscle composition, increases in muscle mass, alterations in skeletal muscle metabolism, improvement in muscular strength and endurance have also been reported in the literature after resistance exercise alone or in combination with aerobic exercise. According to new scientific evidence, appropriate dynamic resistance exercise should be recommended as a safe and effective alternative training mode (supplementary to conventional aerobic exercise) in order to counteract peripheral maladaptation and improve muscle strength, which is necessary for recreational and daily living activities, and thus quality of life, of patients with stable, CHF.

Rehabilitation in Cardiac Patients

This article discusses the effects of training in cardiac rehabilitation and describes the influence of various training modalities on the evolution of exercise capacity in cardiac patients. Both home- and hospital-based studies are analysed separately. From the collected studies, a very heterogeneous character of the content of the rehabilitation programmes appears. Direct comparison of the effects of the training programmes on exercise capacity remains difficult. Baseline factors for predicting a better training outcome are: low exercise capacity and peripheral oxygen extraction; presence of hibernating myocardium; high myocardial perfusion; low degree of coronary vessel occlusion; working status; and improved feelings of wellbeing. The increased work capacity as a result of rehabilitation is associated with: an increased volume density of skeletal muscle mitochondria; peripheral muscular vasodilatory capacity; cardiac output and a decreased left ventricular end-diastolic pressure; depletion of muscular phosphocreatine levels; and degree of restenosis. Home- and hospital-based interventions induce comparable training effects. More research is needed concerning the training modalities in cardiac rehabilitation. There is an influence of weekly training frequency and programme duration on the training outcome. A higher training frequency and/or duration might induce greater training effects. The evolution of the anaerobic threshold is sensitive to the training intensity and inclusion of strength training, which remains to be established for maximal exercise capacity. However, insufficient information is available on the influence of training session duration on the evolution of exercise capacity.

Exercise training for patients with heart failure: a systematic review of factors that improve mortality and morbidity

PURPOSE

To determine the efficacy of exercise training and its effects on outcomes in patients with heart failure.

METHODS

MEDLINE, Medscape, and the Cochrane Controlled Trials Registry were searched for trials of exercise training in heart failure patients. Data relating to training protocol, exercise capacity, and outcome measures were extracted and reviewed.

RESULTS

A total of 81 studies were identified: 30 randomized controlled trials, five nonrandomized controlled trials, nine randomized crossover trials, and 37 longitudinal cohort studies. Exercise training was performed in 2387 patients. The average increment in peak oxygen consumption was 17% in 57 studies that measured oxygen consumption directly, 17% in 40 studies of aerobic training, 9% in three studies that only used strength training, 15% in 13 studies of combined aerobic and strength training, and 16% in the one study on inspiratory training. There were no reports of deaths that were directly related to exercise during more than 60,000 patient-hours of exercise training. During the training and follow-up periods of the randomized controlled trials, there were 56 combined (deaths or adverse events) events in the exercise groups and 75 combined events in the control groups (odds ratio [OR] = 0.98; 95% confidence interval [CI]: 0.61 to 1.32; P = 0.60). During this same period, 26 exercising and 41 nonexercising subjects died (OR = 0.71; 95% CI: 0.37 to 1.02; P = 0.06).

CONCLUSION

Exercise training is safe and effective in patients with heart failure. The risk of adverse events may be reduced, but further studies are required to determine whether there is any mortality benefit.

Does aerobic training lead to a more active lifestyle and improved quality of life in patients with chronic heart failure?

BACKGROUND

Due to dyspnea and fatigue, patients with chronic heart failure (CHF) are often restricted in the performance of everyday activities, which gradually may lead to hypoactivity.

AIMS

To assess whether aerobic training leads to a more active lifestyle and improved quality of life (QoL) in patients with CHF.

METHODS

Patients with stable CHF (NYHA II/III; 59 (11) years) were randomly assigned to a training group (n=18; 3-month aerobic program above standard treatment) or control group (n=16; standard treatment without special advice for exercise). Measurements were performed on level of everyday physical activity (PA, novel accelerometry-based activity monitor) and QoL, and on several related parameters.

RESULTS

Training did not result in a more active lifestyle or improved QoL, but improved (P<0.05) peak power (17%), 6-min walk distance (10%), muscle strength (13-15%) and depression (-1.3 unit). Changes in level of everyday PA were related to changes in peak Vo(2) (r=0.58, P=0.01) and knee extension strength (r=0.48, P=0.05).

CONCLUSIONS

At group level training did not result in a more active lifestyle or improved QoL. However, correlations between training-related changes in parameters suggest that aerobic training has the potential to increase levels of everyday PA in CHF.

Exercise training improves insulin-stimulated myocardial glucose uptake in patients with dilated cardiomyopathy

BACKGROUND

The effects of exercise training on myocardial substrate utilization have not previously been studied in patients with idiopathic dilated cardiomyopathy and mild heart failure.

METHODS AND RESULTS

Myocardial glucose uptake was studied in 15 clinically stable patients with dilated cardiomyopathy (New York Heart Association class I-II, ejection fraction 34% +/- 8%) with the use of 2-[fluorine 18]fluoro-2-deoxy-d-glucose ([F-18]FDG) and positron emission tomography under euglycemic hyperinsulinemia. Eight of these patients participated in a 5-month endurance and strength training program, whereas seven patients served as nontrained subjects. Left ventricular function was assessed by 2-dimensional echocardiography before and after the intervention. After the training period, insulin-stimulated myocardial fractional [F-18]FDG uptake and glucose uptake rates were significantly increased in the anterior, lateral, and septal walls (P <.01) in the trained subjects but remained unchanged in the nontrained subjects. In the trained patients, whole-body insulin-stimulated glucose uptake was enhanced and serum free fatty acid levels were suppressed during hyperinsulinemia compared with the baseline study (P <.05). No changes were observed in the nontrained group.

CONCLUSIONS

These results indicate that exercise training in patients with dilated cardiomyopathy improves insulin-stimulated myocardial glucose uptake. This improvement in glucose uptake may be indicative of a switch in myocardial preference to a more energy-efficient substrate.

The implications of physical activity in patients with chronic heart failure

The clinical syndrome of chronic heart failure is increasingly prevalent. It can be considered a multiorgan disorder that may exert a negative physical and psychological influence on a patient. Medication and surgical intervention have important roles to play and have certainly improved both morbidity and mortality in this field, but clearly these interventions alone are not enough. Excessive resource utilization for this group of patients has provided added impetus to research into non-pharmacological interventions. These encompass dietary and other lifestyle measures, including smoking cessation and exercise. Exercise has been shown to favourably affect the functional capacity and quality of life. There is also emerging evidence that it reduces mortality. In the absence of contraindications, regular endurance exercise coupled with strength training is undoubtedly beneficial. As with other cardiovascular research, there is a trend towards recruiting middle-aged males. This effectively means that practitioners need to be cautious when evaluating and/or implementing research evidence. By addressing the implications of physical activity for deconditioned patients with chronic heart failure, a holistic therapeutic regimen is fostered. This has been shown to improve the quality of life of patients and to enhance the quality of service delivered to this patient group.

Is a long-term high-intensity exercise program effective and safe in patients with rheumatoid arthritis? Results of a randomized controlled trial

OBJECTIVE

There are insufficient data on the effects of long-term intensive exercise in patients with rheumatoid arthritis (RA). We undertook this randomized, controlled, multicenter trial to compare the effectiveness and safety of a 2-year intensive exercise program (Rheumatoid Arthritis Patients In Training [RAPIT]) with those of physical therapy (termed usual care [UC]).

METHODS

Three hundred nine RA patients were assigned to either the RAPIT program or UC. The primary end points were functional ability (assessed by the McMaster Toronto Arthritis [MACTAR] Patient Preference Disability Questionnaire and the Health Assessment Questionnaire [HAQ]) and the effects on radiographic progression in large joints. Secondary end points concerned emotional status and disease activity.

RESULTS

After 2 years, participants in the RAPIT program showed greater improvement in functional ability than participants in UC. The mean difference in change of the MACTAR Questionnaire score was 2.6 (95% confidence interval [95% CI] 0.1, 5.2) over the first year and 3.1 (95% CI 0.7, 5.5) over the second year. After 2 years, the mean difference in change of the HAQ score was -0.09 (95% CI -0.18, -0.01). The median radiographic damage of the large joints did not increase in either group. In both groups, participants with considerable baseline damage showed slightly more progression in damage, and this was more obvious in the RAPIT group. The RAPIT program proved to be effective in improving emotional status. No detrimental effects on disease activity were found.

CONCLUSION

A long-term high-intensity exercise program is more effective than UC in improving functional ability of RA patients. Intensive exercise does not increase radiographic damage of the large joints, except possibly in patients with considerable baseline damage of the large joints.

Effects of an exercise adherence intervention on outcomes in patients with heart failure

The purpose of this study was to determine how an exercise adherence intervention affects the physiological, functional, and quality of life outcomes of patients with heart failure (HF). Sixteen HF patients were randomly assigned to an exercise-only group (n = 8) or to an exercise-with-adherence group (n = 8). Two of the 16 people died from nonexercise related causes during the study and were not included in the analysis. The intervention was tested over a 24-week period in which patients participated in a 12-week supervised exercise program (Phase 1) followed by 12 weeks of unsupervised home exercise (Phase 2). The intervention format was one of individualized graphic feedback on exercise goals and participation and problem-solving support by nurses. Results indicate that patients who received the intervention exercised more frequently and experienced improved outcomes during both phases. The adherence intervention may encourage HF patients to continue to exercise and thereby maintain the health benefits gained in both phases of an exercise program.

Exercise training improves biventricular oxidative metabolism and left ventricular efficiency in patients with dilated cardiomyopathy

OBJECTIVES

The aim of this study was to determine the effect of exercise training on myocardial oxidative metabolism and efficiency in patients with idiopathic dilated cardiomyopathy (DCM) and mild heart failure (HF).

BACKGROUND

Exercise training is known to improve exercise tolerance and quality of life in patients with chronic HF. However, little is known about how exercise training may influence myocardial energetics.

METHODS

Twenty clinically stable patients with DCM (New York Heart Association classes I through III) were prospectively separated into a training group (five-month training program; n = 9) and a non-trained control group (n = 11). Oxidative metabolism in both the right and left ventricles (RV and LV) was measured using [(11)C]acetate and positron emission tomography. Myocardial work power was measured using echocardiography. Myocardial efficiency for forward work was calculated as myocardial work power per mass/LV oxidative metabolism.

RESULTS

Significant improvements were noted in exercise capacity (VO(2)) and ejection fraction in the training group, whereas no changes were observed in the non-trained group. Exercise training reduced both RV and LV oxidative metabolism and elicited a significant increase in LV forward work efficiency, although no significant changes were observed in the non-trained group.

CONCLUSIONS

Exercise training improves exercise tolerance and LV function. This is accompanied by a decrease in biventricular oxidative metabolism and enhanced forward work efficiency. Therefore, exercise training elicits an energetically favorable improvement in myocardial function and exercise tolerance in patients with DCM.

Strength/endurance training versus endurance training in congestive heart failure

PURPOSE

The aim of this study was to compare the effects of endurance training alone (ET) with combined endurance and strength training (CT) on hemodynamic and strength parameters in patients with congestive heart failure (CHF).

METHODS

Twenty male patients with CHF were randomized into one of two training regimens consisting of endurance training or a combination of endurance and resistance training. Group ET had 40-min interval cycle ergometer endurance training three times per week. Group CT combined endurance and strength training with the same interval endurance training for 20 min, followed by 20 min of strength training. Left ventricular function was assessed at baseline and after 40 training sessions by echocardiography and radionuclide ventriculography. Work capacity was measured with cardiopulmonary exercise test (CPX) and lactate determination. Strength was measured with an isokinetic dynamometer.

RESULTS

After 40 sessions, the ET group improved functional class, work capacity, peak torque, and muscular endurance. However, peak O2 remained unchanged. Left ventricular ejection fraction (LVEF) and fractional shortening (FS) decreased, whereas left ventricular end-diastolic diameter (LVED) increased. The CT group improved NYHA score, working capacity, peak O2, and peak lactate; peak torque and muscular endurance, LVEF, and FS increased, whereas LVED decreased. Compared with ET, CT was significantly (P < 0.05) better in improving LV function.

CONCLUSION

Combined endurance/strength training was superior to endurance training alone concerning improvement of LV function, peak VO2, and strength parameters. It appears that for stable CHF patients, a greater benefit can be derived from this training modality.

Staying on course: the effects of an adherence facilitation intervention on home exercise participation

The purpose of this investigation was to test the effectiveness of an adherence facilitation intervention consisting of goal setting, graphic feedback, and provider guidance to support adherence to home exercise in a sample of patients with heart failure who had completed a supervised exercise program. The sample consisted of 13 patients with an ejection fraction of 40% or less who were randomly assigned to either the exercise only group (n=6) or the exercise with adherence facilitation group (n=7). The format of the intervention was graphic depiction of each patient's exercise goals in comparison to each patient's exercise participation. Graphs were mailed at 3-week intervals for 12 weeks. Results indicate that patients who received the intervention demonstrated higher exercise adherence and greater confidence in continuing to exercise in the future. The adherence facilitation intervention may be helpful to heart failure patients in adapting to a program of home exercise. (c)2002 CHF, Inc.

Hemodynamic responses during aerobic and resistance exercise

PURPOSE

Resistance training has become an accepted part of cardiac rehabilitation programs. Because of the potential for a high afterload to have a negative impact on left ventricular function, there has been concern regarding the safety of resistance training for patients with congestive heart failure.

METHODS

This study addressed this concern by studying 12 healthy volunteers, 12 patients with stable coronary artery disease, and 12 patients with stable congestive heart failure during upright cycling at 90% of ventilatory threshold, and during one set of 10 repeated leg presses, shoulder presses, and biceps curls at 60% to 70% of 1-repetition maximum. Left ventricular function was measured by echocardiography.

RESULTS

The pattern of changes in heart rate, blood pressure, left ventricular ejection fraction, wall thickness, and left ventricular internal diameters was similar across all three groups of subjects, although there were large differences in absolute values. Despite elevations in diastolic and mean arterial pressures during resistance exercise, there was no evidence of significant rest-to-exercise deterioration in left ventricular function during leg press (ejection fraction, 60%-59%, 56%-55%, and 38%-37%), shoulder press (66%-65%, 59%-53%, and 38%-35%), or biceps curls (63%-58%, 53%-54%, and 35%-36%), as compared with cycle ergometry (63%-69%, 51%-57%, and 35%-42%) in the healthy control subjects, the patients with coronary artery disease, and the patients with congestive heart failure, respectively.

CONCLUSIONS

Left ventricular function remains stable during moderate-intensity resistance exercise, even in patients with congestive heart failure, suggesting that this form of exercise therapy can be used safely in rehabilitation programs.

Exercise in the geriatric patient with congestive heart failure

The benefits of exercise in the elderly patient with heart failure have been well documented, but the studies have been limited by restrictive inclusion criteria. Most studies have involved patients who are younger and healthier than those normally seen in clinical practice. Improvements in neurohormonal, metabolic, and vascular status have been well documented in the relatively young patients who have been evaluated. Consequently, peak exercise time, oxygen consumption, submaximal exercise, and quality of life have also improved. Studies suggest that older, more severely limited patients may also benefit from exercise. However, they are less likely to tolerate an exercise program and may not improve their quality of life if the exercise is excessive. Caution is warranted when exercise is prescribed to elderly patients with heart failure.

Randomized trial of progressive resistance training to counteract the myopathy of chronic heart failure

Chronic heart failure (CHF) is characterized by a skeletal muscle myopathy not optimally addressed by current treatment paradigms or aerobic exercise. Sixteen older women with CHF were compared with 80 age-matched peers without CHF and randomized to progressive resistance training or control stretching exercises for 10 wk. Women with CHF had significantly lower muscle strength (P < 0.0001) but comparable aerobic capacity to women without CHF. Exercise training was well tolerated and resulted in no changes in resting cardiac indexes in CHF patients. Strength improved by an average of 43.4 +/- 8.8% in resistance trainers vs. -1.7 +/- 2.8% in controls (P = 0.001), muscle endurance by 299 +/- 66% vs. 1 +/- 3% (P = 0.001), and 6-min walk distance by 49 +/- 14 m (13%) vs. -3 +/- 19 m (-3%) (P = 0.03). Increases in type I fiber area (9.5 +/- 16%) and citrate synthase activity (35 +/- 21%) in skeletal muscle were independently predictive of improved 6-min walk distance (r2 = 0.78; P = 0.0024). High-intensity progressive resistance training improves impaired skeletal muscle characteristics and overall exercise performance in older women with CHF. These gains are largely explained by skeletal muscle and not resting cardiac adaptations.