Impaired cerebral blood flow was demonstrated during apnetic episode and related to neuropsychological deficits in sleep apnea patient. To be controlled by the same key feedback mechanism, impaired cerebral blood flow during exercise in EPB patients could be speculated. Moreover, Cerebral hypo-perfusion responses to exercise may contribute to the impairment of functional capacity in patients with HF. Accordingly, we hypothesize that the abnormal cerebral hemodynamics by exercise periodic breathing during exercise is associated with the decline of functional capacity in patients with HF. Besides, 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.