The respiratory sleep disorders are a major cardiovascular risk factor. In fact there is enough scientific evidence that supports the association between apnea-hypopnea syndrome (SASH) and cardiovascular disease (hypertension, stroke, heart failure ....The objective of this study is to estimate the effectiveness of the continuous positive pressure airway (CPAP) in patient with chronic heart failure with normal ejection fraction but dyastolic dysfunction and sleep disordered breathing during the sleep.

Inclusion Criteria:

1. Ejection fraction> 45%, which also ruled out significant left ventricular dilation
2. At least two abnormal indices of diastolic function.

Exclusion Criteria:

1. Not sinus rhytm
2. Severe lung disease (FEV1 or FVC less than 50%)
3. Significant valvular or congenital heart disease, primary
4. Unstable angina, myocardial infarction or cardiac surgery within three months prior to inclusion
5. Hypertrophic Cardiomyopathy
6. Presence of significant psychiatric disorders.
7. Severe Hypersomnia . (Epworth> 20)
8. Severe pulmonary hypertension measured by Doppler,
9. Facial deformity and / or defect of nasal patency.