New Stroke Risk Factor: Sleep Apnea
Death, Stroke Risk Doubles With Obstructive Sleep Apnea
Central Sleep Apnea
There's another kind of sleep apnea. It's called central sleep apnea. Patients with this disorder have the same cycle of choking, waking, and overbreathing. But they don't have a blockage in their throats, says University of Toronto researcher T. Douglas Bradley, MD, director of the center for cardiopulmonary sleep disorders at Toronto General Hospital.
"Central sleep apnea is seen mainly in people with heart failure," Bradley tells WebMD. "It is the lack of a signal in the brain to activate breathing."
Bradley conducted a large study to see whether CPAP can prolong the lives of heart failure patients with central sleep apnea. Unfortunately, the results were inconclusive. The problem wasn't CPAP, Bradley says. It was that during the study there were major advances in the treatment of heart failure.
"There are central sleep apnea patients who would benefit from CPAP, but we cannot tell them their survival will improve," Bradley says. "We can say your heart function will improve. CPAP increases the amount of oxygen in the blood at night. In daytime, it improves the ability of the heart to contract and increases cardiac output. And it decreases central-nervous-system activity, which, in heart failure, is the last thing you want. And it increases exercise capacity. Those are things that are important to heart patients."