Central Sleep Apnea in Patients with Congestive Heart Failure.

Central sleep apnea and Cheyne-Stokes respiration are commonly observed breathing patterns during sleep in patients with congestive heart failure. Common risk factors are male gender, older age, presence of atrial fibrillation, and daytime hypocapnia. Proposed mechanisms include augmented peripheral and central chemoreceptor sensitivity, which increase ventilator instability during both wakefulness and sleep; diminished cerebrovascular reactivity and increased circulation time, which impair the normal buffering of Paco2 and hydrogen ions and delay the detection of changes in Paco2 during sleep; and rostral fluid shifts that predispose to hypocapnia.