Bilevel Positive Pressure Ventilation (BIPAP)in Patients With Sleep Disorders Breathing (SDB)and Congestive Heart Failure (CHF):Comparison of Two Diagnostic Methods

Successful treatment of pulmonary edema was first published in 1938 by A. L. Barach. Since then, this has been the accepted method of treating acute respiratory failure due to left heart failure and edema. The question was raised if pressure supported ventilation during sleep is used to eliminate sleep apneas, would it be useful also for improving congestive heart failure (CHF). Recent studies assessed the role of continuous positive airway pressure (CPAP) in patients with advanced CHF and found the treatment useful. A possible explanation for these results is that central sleep apnea frequently coexists with severe CHF and is not treated or suppressed by CPAP. The frequency of central sleep apnea increases with the severity of CHF and can be found in more than 30% of patients. A few recent studies showed the usefulness of bilevel positive airway pressure (BIPAP) or adaptive servo-ventilation (ASV). ASV led to improvement in ejection fraction as well as in 6 min walking distance testing, and was associated with decreased BNP levels. In another study, bilevel PAP increased LVEF by 7.9%. The limitations of these studies are the small number of patients and that they were conducted on inpatients only. These factors make it difficult to include BIPAP in the guidelines for chronic heart failure therapy. Recently, two outpatient modalities have been introduced to diagnose sleep disordering breathing (SDB). However, no study has directly compared the results of both studies in patients with CHF. Moreover, no studies have assessed improvement in CHF after BIPAP treatment. In addition, the investigators plan to assess the endothelial function in this population before and after BIPAP treatment with the EndoPAT, a noninvasive technology