May 17, 2011

A Healthy Heart for Sleep Apnea Patients

(Ivanhoe Newswire) -- Researchers have demonstrated the effectiveness of a novel treatment that stimulates the nerve that controls the diaphragm to normalize the breathing of patients who suffer from both heart failure and central sleep apnea.

"Many heart failure patients suffer from central sleep apnea, which a number of studies have shown increases mortality in these patients," Shahrokh Javaheri, MD, professor emeritus of medicine at the University of Cincinnati and medical director of Sleepcare Diagnostics in Mason, Ohio, was quoted as saying.

Systolic heart failure describes a medical condition in which the heart no longer pumps blood strongly enough to meet the body's needs. According to the American Heart Association, the number of Americans living with heart failure is estimated at 5.8 million"”a number that is expected to grow as people live longer and the population ages.

In this study, Dr. Javaheri and his colleagues conducted an investigation of 16 patients. All 16 patients were diagnosed with heart failure (mean left ventricular ejection fraction of 30 percent) and central sleep apnea.

The patients served as their own control group, receiving on one night phrenic nerve stimulation and no therapeutic intervention on another. The intervention, which acts like a pacemaker for the nerve, dramatically reduced the number of times patients stopped, or almost stopped, breathing; improved blood oxygenation levels while sleeping; and resulted in a healthier heart rate.

Compared to the control night, phrenic nerve stimulation resulted in the virtual elimination of central sleep apnea. There was a significant decrease in apnea, in associated arousal and in the reduced number of times the patient experienced 4 percent oxygen desaturation. Overnight sleep heart rate decreased significantly.

The current best treatment for these patients is Continuous Positive Airway Pressure (CPAP). In about half of all patients, CPAP suppresses central sleep apnea and improves cardiovascular health and mortality, according to Dr. Javaheri. However, even among those patients that could be helped by CPAP, many cannot tolerate sleeping an entire night with a nasal mask, so the percentage of patients helped by CPAP is considerably lower.

"Our research suggests," said Dr. Javaheri, "that there is a new therapy"”one that, unlike CPAP and other existing mask-based therapies, could be tolerated by all patients."

SOUCE: ATS 2011 International Conference, May 13, 2011