Bringing Sleep, Heart Health Together
More Beats, Improved Sleep continued...
"The benefits of pacing in this study were less than would be anticipated with the standard therapy for OSA -- namely, continuous positive airway pressure," he says. "Patients with symptomatic OSA should be advised to seek standard therapy for this condition."
He adds that patients who already have a dual-chamber cardiac pacemaker for sinus node dysfunction and who also have mild sleep apnea may want to talk to their cardiologists about pacing as therapy for obstructive sleep apnea.
"It's important to note that while the findings apply to a small group of people, it may point the way to the development of new therapies, including drug therapy, for this common medical condition," Gottlieb says.
"Common" may be an understatement.
"OSA is significantly underdiagnosed, and its consequences are a burden on the healthcare system," says David White, MD, associate professor at the Harvard University School of Medicine and director of the Sleep Disorders Program at Brigham and Women's Hospital in Boston.
According to the National Institutes of Health, obstructive sleep apnea affects more than 18 million people in the United States. In addition to the heart problems it causes, the disorder is associated with cognitive and behavioral impairment, daytime fatigue, and related motor vehicle and work accidents.
Doctors usually use what are called polysomnographic measures to evaluate patients with obstructive sleep apnea. This requires an overnight stay in a sleep lab while connected to multiple leads that monitor heart, respiratory, muscle, and brain functions.
But the FDA in January approved a new technology to make diagnosing sleep apnea much easier. Using a system called "Watch PAT100," a device is worn on the wrist and a noninvasive finger probe measures the patient's body functions during sleep. It is manufactured by Itamar Medical Co., based in Israel.
The device detects changes in peripheral arterial tone, or PAT. PAT is a newly identified physiological signal that reports changes in arterial volume in the fingertip from pulsing blood. These changes have been shown in clinical trials to be a reliable indicator of sleep-related breathing disorders. The device records signals and stores them in a removable memory card. The data are downloaded to a computer for analysis to detect sleep-related breathing disorders.