Heart failure (HF) is a complex syndrome characterized by myocardial dysfunction and an impaired regulatory function of multiple organ systems which were resulted from impaired cardiac output and consequently impaired perfusion of target organ. In cardiopulmonary exercise test (CPET), the investigators found there is periodic oscillation in minute ventilation of some patient. With periodic breathing (PB), clear oscillations in oxygen uptake, carbon dioxide output, tidal volume and left ventricle ejection fraction (LVEF) were also noted. Exertional hyper-ventilation that is caused by HF may further induce vasoconstriction during exercise and lead to further dysfunction of end-organ and muscle. Reduced end-organ perfusion/oxygenation may critically limit exercise performance. Hypoxic change during nadir phase of PB may deteriorate the exercise limitation. Physical training can have beneficial effects which can effectively counteract the progression of deleterious compensatory mechanisms of HF. Whether exercise yields the same beneficial effect on ventilation oscillation and inefficacy is not clear. The investigators will observe the real-time cardiac and hemodynamic change respond to exercise with periodic breathing change. The investigators expect that these results obtained from this study can aid in determining appropriate exercise intervention to improve aerobic fitness as well as simultaneously improve hemodynamic control in patients with HF. A quasi-experimental design will be used in this investigation. 60 HF patients will be recruited from Chang Gung Medical Foundation, Keelung Branch after they have provided informed consent. These subjects will be divided into PB (n=30) and non-PB groups (n=30) by their expression of CPET. Patients from each groups received the same therapy and trace course for 2years including CV clinics, CPET and polysomnography. The investigators will measure subjects' physical fitness, oxygen transport and utilization of exercising skeletal muscles, cardiovascular functions and hemodynamics, blood cell parameters, RBC deformity and aggregation, plasma biomarkers of myocardial damage, oxygen stress and quality of life at pre-training stage and following the 6th , 12th, 18th, 24th months of the tracing program. Experimental results were analyzed by descriptive statistics, independent t-test, and repeated measure ANOVA. The investigators study the above parameter to realize the physiological response to exercise of these patients and discover the appropriate exercise intensity for prescription for EPB.
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VO2 max(maximal oxygen consumption)
Timeframe: 2 years