Sleep Apnea and Heart Disease
Along with the epidemic of obesity, the incidence of sleep apnea has risen at an alarming rate. The most common form, known as obstructive sleep apnea (OSA), is caused by extra tissue in the upper airway that collapses and literally blocks the airflow to the lungs.
The risk factors for OSA include the male sex
(women's risk increases after menopause), obesity,
and neck size greater than 17 inches. The symptoms
of sleep apnea include fatigue, early morning
headaches, snoring, falling asleep during the
daytime, depression and witnessed episodes of
irregular breathing while sleeping.
Treatment of OSA typically includes the use of continuous positive airway pressure (CPAP) via a special mask that is worn at night. CPAP provides increased pressure to the inside of the airway, keeping it open and allowing air to freely pass into the lungs. Other treatments include weight loss, special devices worn in the mouth, and surgery to the upper airway.
Over the past several years, researchers have been studying the consequences of sleep apnea on the heart. With sleep apnea, very high levels of the stress hormone epinephrine are released hundreds of times each night. This “fight or flight” hormone puts a tremendous strain on the heart, blood vessels and other organs and also disrupts sleep. This may be one mechanism by which sleep apnea can injure the heart and blood vessels.
The strongest association has connected sleep apnea with high blood pressure. Studies have demonstrated that treating sleep apnea will decrease blood pressure even during the daytime without the need to add additional medications.
The National Guidelines (JNC VII) used by physicians to treat high blood pressure list OSA as a major cause of refractory high blood pressure. Recently, more worrisome connections linking OSA to an increased risk of stroke and heart attack have been published. Even after eliminating other risk factors, those with OSA are much more likely to suffer either a stroke or heart attack making sleep apnea a potent risk factor that should be aggressively treated. Sleep apnea is also associated with a variety of other cardiovascular disorders including heart failure, atrial fibrillation and sudden cardiac death.
The Heart Failure Program and the Sleep Medicine
Program of the University of Pennsylvania have
joined together to address the many aspects of
this significant health concern. The leaders
of this cooperative effort are Ilene
Rosen, MD in the Division of Sleep Medicine,
and Lee
Goldberg, MD, in the Division of Cardiovascular
Medicine.
As research partners, Dr. Rosen, Dr.
Goldberg and their co-workers study the consequences
and treatment of sleep apnea in people with heart
disease. This has resulted in the initiation
of a multi-center clinical trial evaluating the
treatment of a specific type of sleep apnea on
heart failure symptoms. In addition, another
proposed trial of screening and treating OSA
and heart failure is being finalized. Finally,
collaboration between sleep physicians and cardiologists
is underway to look at sleep apnea and its effects
on treatment outcomes in patients with atrial
fibrillation.
Over the past year, the Sleep Center and The Heart Failure Program have developed a clinical pathway to rapidly evaluate and treat any person suspected of having sleep apnea that may be complicating their heart disease. This has led to more rapid diagnosis and treatment and combined with other therapies should improve the quality of life for those impacted by both sleep apnea and heart disease.
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