The aim of this study is to compare the effects of Adaptive Servo Ventilation (Bipap® auto SV Advanced) and oxygen therapy in chronic heart failure patients complicated with central sleep apnea.

Central sleep apnea(CSA) is associated with chronic heart failure(CHF). At present, both of nocturnal oxygen therapy and adaptive servo ventilation(ASV) are recognized as effective modalities. However,in fact, majority of CHF patients are complicated not only with CSA but with obstructive sleep apnea(OSA). Recently, Philips developed Bipap® auto SV Advanced for such patients. It has auto-CPAP function as the modality of OSAS, in addition to ASV function. The present study is prospective randomised study to compare the effects of nocturnal oxygen therapy and Bipap® auto SV Advanced.

Inclusion Criteria:

• Left ventricular ejection fraction<50% confirmed by echocardiography
• Apnea hypopnea index(AHI)>=20 confirmed by overnight polysomnography
• More than 15% of AHI is due to CSA

Exclusion Criteria:

• Changes of cardioactive drug prescriptions within 6 weeks
• Admission due to cardiovascular events within 6 weeks
• Ever used CPAP or ASV for sleep apnea
• Ever used nocturnal oxgen therapy
• Subjects with acute exacerbation of chronic heart failure
• Operation for upper airway within 90 days
• Renal dialysis
• History of stroke with neurological deficit