Responses to arm exercise in patients with compensated heart failure

Upper Limb Energy Demand During Unilateral Arm Crank Submaximal Exercise Testing in Individuals With Chronic Stroke

OBJECTIVE

To investigate upper limb (UL) energy demand during unilateral arm crank submaximal exercise testing in individuals with stroke compared with healthy controls and the relationship between UL energy demand and UL activity in individuals with stroke.

DESIGN

Cross-sectional, observational study.

SETTING

Research laboratory.

PARTICIPANTS

Individuals with chronic stroke (n=14) and controls (n=12), matched for age, sex, and body mass index (N=26).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

UL energy demand was measured as peak oxygen consumption (V̇o₂)/peak load during unilateral arm crank submaximal exercise testing. UL activity was measured using the Box and Block Test (BBT) and Grooved Pegboard Test (GPT).

RESULTS

The energy demand of the paretic side compared with the nonparetic side of the stroke group was 0.43 mL/kg/min/W (95% confidence interval, 0.03-0.83, P=.005) greater than the dominant compared with the nondominant side of the control group. The median difference between sides in peak V̇o₂/peak load was 52% for the group with stroke compared with 11% for the control group. Positive correlations between the median percentage difference between the paretic and the nonparetic side of peak V̇o₂/peak load and BBT were 0.72 (P=.004) and of V̇o₂/peak load and GPT was 0.77 (P=.002).

CONCLUSIONS

The higher energy demand of the paretic UL during unilateral arm crank submaximal exercise testing than the nonparetic and both UL of the controls together with the strong relationship between energy demand and UL activity suggest that the energy demand of the paretic UL has the potential to affect real-life UL activity after stroke.

Role and benefits of exercise in the management of patients with heart failure

Initial research established the feasibility of exercise training in patients with heart failure, as well as associated physiological benefits. This review summarizes the findings from over two dozen single-site studies that address the effect of exercise training on exercise capacity and cardiovascular and peripheral function. In addition, it incorporates the results from two meta-analyses and a recently completed multi-center trial, all of which studied the effects of exercise training on clinical outcomes. The major conclusions from these studies are that exercise training is safe; improves health status and exercise capacity; helps attenuate much of the abnormal pathophysiology that develops with heart failure; and yields a modest reduction in clinical events. The magnitude of the clinical benefits appears related to the volume of exercise completed. Future research is needed to identify which patient subgroups might benefit the most from exercise training, the optimal exercise dose or load needed to lessen disease-related symptoms and maximize clinical benefit, and the effects of exercise training in patients with heart failure and preserved left ventricular systolic function.

Upper-Extremity Exercise Training in Heart Failure

PURPOSE

Aerobic exercise training (ExTR), predominantly performed with lower extremities, has been used to reverse heart failure (HF)-related exercise intolerance. The present study determined the safety and efficacy of upper-extremity exercise in HF subjects because daily activities are performed using both upper and lower extremities and there is little cross-training effects between extremities.

METHODS

Seven subjects underwent 36 sessions (40 minutes, 3 times per week for 12 weeks) of upper-extremity ExTR (ARM ExTR) using arm ergometers, the arm function of a NuStep device, and an Airdyne stationary cycle. Exercise intensity and duration during weeks 1 to 4 were gradually increased to achieve a 75% to 85% peak heart rate. Pre- and post-ExTR tests included arm ergometer cardiopulmonary testing with echocardiography and quality of life self-administered surveys.

RESULTS

After ARM ExTR test duration increased by 22% (P = .008), respiratory exchange ratio increased by 10% (P = .02), whereas peak oxygen consumption was not improved. Echocardiographic parameters were not altered by ARM ExTR. The total scores of both the Minnesota Living With Heart Failure Questionnaire (P = .02) and the Medical Outcomes Study-36 questionnaire (P = .05) were improved, but the Functional Status Questionnaire scores were not improved.

CONCLUSIONS

Although this study was limited in the number of subjects and lacked a control group, results indicate that ARM ExTR is safe and well-tolerated by persons diagnosed with HF, a finding that is relevant for individuals with HF who cannot exercise with lower extremities.

Exercise rehabilitation in chronic heart failure

The past 15 years of research involving patients with heart failure have provided a lot of new information regarding how exercise training lessens the exercise intolerance that is characteristic of these patients. Despite these new understandings, the prescription of regular exercise and rehabilitation in eligible patients is not embraced by all practitioners. Such reluctance may be due, in part, to concerns about either the safety of the treatment or the absence of multisite, randomized, controlled trial data that evaluates clinical end-points. This paper focuses on how exercise capacity is improved through training in patients with heart failure and suggests future considerations with respect to the study and application of this novel therapy.

Exercise testing and training of patients with heart failure due to left ventricular systolic dysfunction

Reducing the exercise intolerance and symptoms experienced by patients with chronic heart failure remains an important focus in their clinical care. A clear shortcoming exists; however, with respect to an appreciation that in addition to standard medical therapy, selected patients with stable heart failure also can benefit from a moderate exercise training program. Improvements in central transport, regional blood flow, and skeletal muscle histology and biochemistry all likely account for the increase in exercise capacity and delay in fatigue that these patients experience. Additionally, the autonomic imbalance that is characteristic of these patients is improved. Although the number of patients with heart failure participating in an exercise program is increasing, much work still exists relative to incorporating this treatment method into the care plans established by physicians and physician extenders.