Congestive heartfailure (CHF) and sleep apnea-hypopnea syndrome (SAHS) are two conditions highly prevalent in the general population that often co-exist in the same patient. Patients with CHF often present disordered breathing during sleep that is characterized by episodes of central or obstructive apneas, whereas patients with SAHS suffer significant cardiovascular sequelae. The pathophysiological interactions between the two conditions involve both mechanical and neural effects, implicating the sympathetic nervous system. The application of non-invasive ventilation for the treatment of SAHS has beneficial effects on the concurrent CHF, providing new therapeutic horizons for this syndrome. Pneumon 2005,18(1):26-33.