Washington: A pacemaker-like device implanted just under the collar bone can improve sleep in patients with central sleep apnea, scientists say.
The small implant being studied for the treatment of central sleep apnea is showing significant promise, according to Dr William Abraham, director of the Division of Cardiovascular Medicine at The Ohio State University Wexner Medical Center.
Unlike the more common obstructive sleep apnea, in which the airway gets blocked during sleep and causes pauses in breathing, central sleep apnea is more dangerous because the brain's signals to tell the body to breathe get interrupted.
"Central sleep apnea affects more than a third of heart failure patients and is known to make the condition worse," Abraham said.
"Unfortunately, we don't have good treatments available for this type of apnea. Currently, positive airway pressure devices are used, but many patients don't tolerate it well," he said.
"One of the concerning features of central sleep apnea is that these patients don't fit the usual profile of obstructive sleep apnea," said Dr Rami Khayat, a sleep medicine expert and director of Ohio State's sleep heart programme.
"They generally don't snore, so they're tougher to diagnose, and the symptoms of sleepiness and fatigue overlap with symptoms associated with heart failure," Khayat said.
Abraham and other researchers at 11 centers around the world tested the feasibility, safety and efficacy of a new transvenous phrenic nerve stimulator made by the US-based company Respicardia Inc.
The device resembles a pacemaker in that it delivers a regular signal to stimulate the diaphragm to breathe during sleep.
In the pilot study, 47 patients were implanted with the device and evaluated for six months. The implant was placed below the collar bone and a transvenous stimulator lead was positioned near the phrenic nerve.
After a one-month healing period, the device was turned on and programmed to the patient's sleep habits.
Researchers saw significant results, including a 56 per cent reduction in overall apnea events per hour and more than 80 per cent reduction in central sleep apnea events.
"The device normalised breathing during sleep, it reduced apnea episodes and, in association with that, we saw improvements in sleepiness symptoms and patients' quality of life," Abraham said.
"We also noted a reduction in blood pressure in patients with hypertension," he added.
Now researchers are comparing the device to current medical therapy for central sleep apnea in a larger randomised, controlled clinical trial.