Einsatz von Kraftausdauertraining und Muskelaufbautraining in der kardiologischen Rehabilitation

Cardiac rehabilitation in Germany

The purpose of this review is to give an overview of the rehabilitation measures provided for cardiac patients in Germany and to outline its legal basis and outcomes. In Germany the cardiac rehabilitation system is different from rehabilitation measures in other European countries. Cardiac rehabilitation in Germany since 1885 is based on specific laws and the regulations of insurance providers. Cardiac rehabilitation has predominantly been offered as an inpatient service, but has recently been complemented by outpatient services. A general agreement on the different indications for offering these two services has yet to be reached. Cardiac rehabilitation is mainly offered after an acute cardiac event and bypass surgery. It is also indicated in severe heart failure and special cases of percutaneous coronary intervention. Most patients are men (>65%) and the age at which events occur is increasing. The benefits obtained during the 3-4 weeks after an acute event, and confirmed in numerous studies, are often later lost under 'usual care' conditions. Many attempts have been made by rehabilitation institutions to improve this deficit by providing intensive aftercare. One instrument set up to achieve this is the nationwide institution currently comprising more than 6000 heart groups with approximately 120000 outpatients. After coronary artery bypass grafting or acute coronary syndrome cardiac rehabilitation can usually be started within 10 days. The multidisciplinary rehabilitation team consists of cardiologists, psychologists, exercise therapists, social workers, nutritionists and nurses. The positive effects of cardiac rehabilitation are also important economically, for example, for the improvement of secondary prevention and vocational integration.

Reliability and day-to-day variability of peak fat oxidation during treadmill ergometry

Background

Exercising at intensities where fat oxidation rates are high has been shown to induce metabolic benefits in recreational and health-oriented sportsmen. The exercise intensity (Fat_peak) eliciting peak fat oxidation rates is therefore of particular interest when aiming to prescribe exercise for the purpose of fat oxidation and related metabolic effects. Although running and walking are feasible and popular among the target population, no reliable protocols are available to assess Fat_peak as well as its actual velocity (V_PFO) during treadmill ergometry. Our purpose was therefore, to assess the reliability and day-to-day variability of V_PFO and Fat_peak during treadmill ergometry running.

Methods

Sixteen recreational athletes (f = 7, m = 9; 25 ± 3 y; 1.76 ± 0.09 m; 68.3 ± 13.7 kg; 23.1 ± 2.9 kg/m²) performed 2 different running protocols on 3 different days with standardized nutrition the day before testing. At day 1, peak oxygen uptake (VO_2peak) and the velocities at the aerobic threshold (V_LT) and respiratory exchange ratio (RER) of 1.00 (V_RER) were assessed. At days 2 and 3, subjects ran an identical submaximal incremental test (Fat-peak test) composed of a 10 min warm-up (70 % V_LT) followed by 5 stages of 6 min with equal increments (stage 1 = V_LT, stage 5 = V_RER). Breath-by-breath gas exchange data was measured continuously and used to determine fat oxidation rates. A third order polynomial function was used to identify V_PFO and subsequently Fat_peak. The reproducibility and variability of variables was verified with an intraclass correlation coefficient (ICC), Pearson’s correlation coefficient, coefficient of variation (CV) and the mean differences (bias) ± 95 % limits of agreement (LoA).

Results

ICC, Pearson’s correlation and CV for V_PFO and Fat_peak were 0.98, 0.97, 5.0 %; and 0.90, 0.81, 7.0 %, respectively. Bias ± 95 % LoA was −0.3 ± 0.9 km/h for V_PFO and −2 ± 8 % of VO_2peak for Fat_peak.

Conclusion

In summary, relative and absolute reliability indicators for V_PFO and Fat_peak were found to be excellent. The observed LoA may now serve as a basis for future training prescriptions, although fat oxidation rates at prolonged exercise bouts at this intensity still need to be investigated.

[Individualization of exercise load control for inpatient cardiac rehabilitation. Development and evaluation of a HRV-based intervention program for patients with ischemic heart failure]

BACKGROUND

The effective use of rehabilitation programs is of primary importance in order to improve the physical performance of cardiac disease patients. A modular program has been developed which is intended to structure and individualize conventional, exercise-based rehabilitation programs according to the individual needs and physical condition of each patient. The individualization of the program is based on detailed diagnostics before patients enter the program and daily measurements of heart rate variability (HRV) during cardiac rehabilitation.

METHODS

A total of 30 patients with ischemic heart disease were randomly assigned either to the intervention group (IG), completing the modular individualized rehabilitation program [n=15, mean age 54.4±4.2 years and mean left ventricular ejection fraction (LVEF) 28.53±6.25%) or to the control group (CG) taking part in the conventional rehabilitation program (n=15, mean age 56.4±4.4 years and mean LVEF 27.63±5.62). Before and after the intervention, cardiorespiratory fitness was assessed by measurement of maximal oxygen consumption (relative VO2max) during bicycle ergometry and the 6-minute walk test (6-MWT). Pre-post comparisons of cardiorespiratory fitness indicators were used to evaluate the effectiveness of the rehabilitation program. In addition to the results of the basic clinical investigations and the cardiorespiratory testing, results of standardized HRV measurements of 10 min at morning rest served as criteria for program individualization.

RESULTS

The relative VO2max increased significantly (p<0.05) in the IG whereas no change was found in the CG. Similar results were found for maximum power output during bicycle ergometry (p<0.01) and for 6-MWT distance (p<0.001). Although patients in the IG completed less aerobic exercise sessions than those in the CG (p<0.001) the physical performance of the IG improved significantly.

DISCUSSION

The results prove the effectiveness and efficacy of the modular individualized rehabilitation program. They further suggest the need for an individual program matrix instead of a maximum performance matrix in cardiac rehabilitation. Individualization should be based on clinical and performance diagnostics before and accompanying assessments of training condition, e.g. by HRV measurements, during rehabilitation programs. Each patient should only perform those intervention programs which match the results of the basic clinical investigation and additional analyses during rehabilitation.

[Outpatient rehabilitation after myocardial infarction or for heart failure]

Reducing cardiac mortality and improving quality of life are the main objectives of cardiac rehabilitation. In recent years, outpatient rehabilitation within easy patient reach has achieved the same status as inpatient rehabilitation. Outpatient rehabilitation permits close involvement of the patient's family and social environment, thus easing reintegration into everyday life. However, the health care system is not yet utilizing outpatient rehabilitation to its full potential. This contribution illustrates the principles of rehabilitation following myocardial infarction or for heart failure in an outpatient setting, as well as its potential and future development.