Exercise following heart transplantation

Time course of physical reconditioning during exercise rehabilitation late after heart transplantation

BACKGROUND

Exercise rehabilitation improves physical capacity in heart transplant recipients. The time course of physical reconditioning and skeletal muscle adaptation late after transplantation are unknown.

METHODS

Twenty-one heart transplant recipients, at 5.2 +/- 2.1 years after transplantation, completed 1 year of an individually tailored home ergometer-training program (2.1 +/- 0.7 sessions weekly with matched heart rates, intensity at 10% below anaerobic threshold). We analyzed time course of physical reconditioning data for each home-training session (n = 2,396). Constant-load tests with consistent blood lactate concentrations were performed quarterly (n = 105) to estimate the time course of skeletal muscle adaptation. Nine heart transplant recipients served as a control group (CG).

RESULTS

After 12 months, exercise capacity for matched heart rates (112 +/- 11 beats/min; CG, 114 +/- 8 beats/min) increased by 35% +/- 19% (from 43 +/- 14 to 58 +/- 18 W; p < 0.001; CG, 53 +/- 18 to 54 +/- 18 W); 24% of the increase was caused by improved skeletal muscle function and 11% by central functioning. Physical reconditioning showed its greatest increase within the first 3 months (+18%; p < 0.001); 50% of the increase consisted of better skeletal muscle or central functioning. Between the 4(th) and 12(th) months, exercise capacity increased continuously (+15%; p < 0.001), mainly because of better skeletal muscle functioning.

CONCLUSIONS

The persistent improvement in exercise capacity along with consistent lactate concentrations during 12 months of training indicates that exercise training could counteract the negative side effects of immunosuppressive treatment on skeletal muscles. Even late after heart transplantation, physical training should be performed regularly to prevent the accelerated decrease in exercise capacity and in skeletal muscle function.

Sex differences in respiratory exercise physiology

Respiratory exercise physiology research has historically focused on male subjects. In the last 20 years, important physiological and functional differences have been noted between the male and female response to dynamic exercise where sex differences have been reported for most of the major determinants of exercise capacity. Female participation in competitive and recreational sport is growing worldwide and it is universally accepted that participation in regular physical activity is of health benefit for both sexes. Understanding sex differences is of potential importance to both the clinician-scientist and the exercise physiologist since differences could impact upon exercise rehabilitation programmes for patient populations, exercise prescription for disease prevention in healthy individuals and training strategies for competitive athletes. Sex differences have been shown in resting pulmonary function, which may impact on the respiratory response to exercise. Women typically have smaller lung volumes and maximal expiratory flow rates even when corrected for height relative to men. Differences in resting and exercising ventilation across the menstrual cycle and relative to men have also been reported, although the functional significance remains unclear. Expiratory flow limitation and a high work of breathing are seen in women. Pulmonary system limitations, in particular exercise-induced arterial hypoxia, have been reported in both men and women; however, the prevalence in women is not yet known. From the available literature, it appears that there are sex differences in some areas of respiratory exercise physiology. However, detailed sex comparisons are difficult because the number of subjects studied to date has been woefully small.

Slowing of bone loss in patients with rheumatoid arthritis by long-term high-intensity exercise: results of a randomized, controlled trial

OBJECTIVE

Patients with rheumatoid arthritis (RA) are more at risk for the development of osteoporosis and osteoporotic fractures than are their healthy peers. In this randomized, controlled, multicenter trial, the effectiveness of a 2-year high-intensity weight-bearing exercise program (the Rheumatoid-Arthritis-Patients-In-Training [RAPIT] program) on bone mineral density (BMD) was compared with usual care physical therapy, and the exercise modalities associated with changes in BMD were determined.

METHODS

Three hundred nine patients with RA were assigned to an intervention group, either the RAPIT program or usual care physical therapy. The primary end points were BMD of the hip and spine. The exercise modalities examined were aerobic fitness, muscle strength, and, as a surrogate for those effects not directly measured by the RAPIT program, attendance rate.

RESULTS

The data on the 136 RAPIT participants and 145 usual care participants who completed the study were analyzed. The mean rate of decrease in hip BMD, but not in lumbar spine BMD, was smaller in patients participating in the RAPIT program when compared with that in the usual care group, with a mean decrease of 1.6% (95% confidence interval [95% CI] 0.8-2.5) over the first year and 0.5% (95% CI 1.1-2.0) over the second year. The change in hip BMD was significantly and independently associated with changes in both muscle strength (multivariate odds ratio [OR] 1.75, 95% CI 1.07-2.86) and aerobic fitness (OR 1.79, 95% CI 1.10-2.90), but not with the attendance rate (OR 1.00, 95% CI 0.99-1.00).

CONCLUSION

A long-term high-intensity weight-bearing exercise program for RA patients is effective in slowing down the loss of BMD at the hip. The exercise modalities associated with this effect are muscle strength and aerobic fitness.

Effects of upper extremity exercise training on peak aerobic and anaerobic fitness in patients after transplantation

We found that patients with transplants, regardless of transplant type, and sedentary control subjects experience significant increases in aerobic fitness after 10 weeks of Dragon boat training. However, the magnitude of improvement in aerobic fitness depends on the transplant type, with patients having cardiac transplant experiencing greater relative changes in response to training than patients with noncardiac transplant. It also appears that patients with cardiac and noncardiac transplants have an increased reliance on anaerobic energy systems during exercise conditions compared with healthy control subjects.

Successful heart-lung transplantation in a patient with kyphoscoliosis

The association is well established between congenital heart disease and spinal deformities such as scoliosis or kyphosis, but data are not available for risks and the outcome of heart surgery in patients with spinal deformities. We report a case of successful orthotopic heart lung transplantation in a patient with complex congenital heart disease and severe chest deformity who had undergone previous spinal fusion surgery for progressive right convex thoracic kyphoscoliosis.

Physical activity patterns and exercise performance in cardiac transplant recipients

BACKGROUND

Cardiac transplantation (CTX) improves exercise tolerance, but CTX recipients still achieve only 50% to 70% of normal values for exercise capacity. Among the factors suggested to explain the reduced exercise tolerance in CTX recipients is deconditioning. Little is known about the relation between physical activity patterns and exercise test responses in CTX patients.

METHODS

Forty-seven CTX patients (mean age 47 +/- 12 years; mean 4.8 +/- 3.0 years after CTX) underwent maximal exercise testing and assessment of current and past physical activity patterns using a questionnaire. Energy expenditure from recreational and occupational activities over the last year and for adulthood were expressed in kcal/week and correlated with peak oxygen consumption (VO(2)), VO(2) at the ventilatory threshold, and the percentage of age-predicted peak VO(2) achieved.

RESULTS

The patients reported expending a mean of approximately 1100 kcal/week in recreational activity, suggesting a moderate level of physical activity is maintained after CTX. The mean peak VO(2) achieved for the group was 17.2 +/- 5.2 mL/kg/min, corresponding to 59% +/- 14% of age-predicted exercise capacity. Significant but modest associations were observed between recreational energy expenditure during the last year and percentage of age-predicted peak VO(2) achieved (r = 0.34, P <.01), and VO(2) at the ventilatory threshold (r = 0.45, P <.01). Energy expenditure from blocks walked and stairs climbed per week was modestly associated with peak VO(2) (r = 0.36, P <.05), percentage of predicted peak VO(2) achieved (r = 0.39, P <.01), and VO(2) at the ventilatory threshold (r = 0.42, P <.01). Exercise capacity was poorly related to occupational and recreational activities when expressed as average weekly energy expended throughout adulthood.

CONCLUSION

Post-CTX patients maintain a moderately active lifestyle. Measures of exercise tolerance generally are related to recent daily recreational activities in CTX patients, but these associations are modest. The many physiologic factors unique to CTX recipients likely play a more important role than deconditioning in determining exercise tolerance in these patients.

Lifestyle and quality of life in long-term cardiac transplant recipients

BACKGROUND

The purposes of this study were to describe long-term (>1 year) cardiac transplant recipients' perceptions of barriers to health-promoting behaviors; ability to manage their health, health-promoting lifestyle, health status and quality of life (QOL); and determine predictors of QOL.

METHODS

Data were collected from 93 recipients who completed a self-report questionnaire incorporating: (1). patient characteristics; (2). barriers to health promotion, perceived health competence and health-promoting lifestyle; (3). perceived health status; and (4). QOL. All instruments used had acceptable reliability and validity. Objective measures of health status were retrieved from medical records. Data were analyzed using descriptive and comparative statistics, measures of association and multiple regression.

RESULTS

Recipients were uncertain about their ability to manage their health; felt that barriers sometimes interfered with engaging in health-promoting behaviors; and often included health-promoting behaviors in their lifestyle. They rated their health as good and were moderately satisfied with life. Predictors of better perceptions of QOL included less education, longer time since transplant, ischemic etiology of heart failure, fewer barriers, higher perceived health competence and a health-promoting lifestyle (R(2) = 0.51; F = 14.77; p = 0.001).

CONCLUSIONS

The present results provide information regarding factors that contribute to perceptions of quality of life after cardiac transplantation, have implications for identifying patients at risk for poor QOL, and sensitize clinicians to the need for ongoing patient education.

Effects of an enhanced heart rate reserve on aerobic performance in patients with a heart transplant

OBJECTIVE

The aim of this study was to investigate whether a high-intensity warm-up at the start of a graded, symptom-limited exercise test would enhance heart rate reserve and thus improve the aerobic performance of orthotopic heart transplant patients.

DESIGN

Adrenal and cardiorespiratory responses were compared in 10 orthotopic heart transplant patients who performed two graded, symptom-limited exercise tests on an ergocycle.

RESULTS

At the start of the graded, symptom-limited exercise test, high intensity increased the norepinephrine level more than usual intensity between rest and the third minute of exercise. This higher norepinephrine level was followed by a higher heart rate response from the fourth minute of exercise. Heart rate reserve was enhanced during high-intensity exercise, without any significant change in peak oxygen uptake.

CONCLUSIONS

This specific warm-up enhanced heart rate reserve during a graded, symptom-limited exercise test on an ergocycle. Mechanisms more important than limited heart rate reserve are involved in the limitation of exercise tolerance in orthotopic heart transplant patients.

Lifestyle and health status in long-term cardiac transplant recipients

OBJECTIVE

The purpose of this pilot study was to describe the lifestyle and health status of long-term cardiac transplant recipients.

DESIGN AND SETTING

The study was a descriptive correlational design at a health sciences center.

MEASURES

We measured lifestyle, using the Health-Promoting Lifestyle Profile-II, and indicators of health status (eg, number of medications, infections, and rejections; systolic and diastolic blood pressure; lipid profile; and percent ideal body weight) in 47 patients after an annual evaluation or follow-up visit after patients received cardiac transplantation.

RESULTS

Patients were primarily male, white, 56.5 years old and 75.6 months after transplant. Spiritual growth was the most frequently reported lifestyle characteristic (mean, 27.4; SD, 4.9). The least frequently reported lifestyle characteristic was engagement in physical activity (mean, 18.4; SD, 5.7). Factorial between-subjects analysis of variance demonstrated that women had a higher high-density lipoprotein level (P =.0001) and reported healthier dietary habits (P =.02) and greater spiritual growth (P =.006) than men. African Americans reported poorer stress management behaviors (P =.04). Recipients whose heart failure was due to ischemic cardiomyopathy had a lower percent ideal body weight than those with a nonischemic cause (P =.01). Recipients with cardiac allograft vasculopathy had a higher low-density lipoprotein cholesterol level (P =.05) and lower high-density lipoprotein cholesterol level (P =.05) than those without cardiac allograft vasculopathy, and those persons who required maintenance corticosteroid therapy reported poorer interpersonal relationships than those persons not receiving corticosteroids (P =.04).

CONCLUSION

Cardiac transplant recipients did not consistently include health-promoting behaviors in their lifestyles although some of the behaviors were associated with a better health status. Future research should be aimed at identifying factors that affect the ability to make and sustain changes in lifestyle and improve health status.