Sleep apnea should be considered in all patients with heart disease and those at risk for heart disease. Most patients who have sleep apnea have characteristic symptoms which can be identified during an interview with a health care provider. A referral to a sleep specialist should be pursued if there is any suspicion of sleep apnea.
The following are some points to remember about sleep apnea and heart disease:
Sleep Apnea. Sleep apnea is common in patients with established heart disease, and contributes to the known risk factors for the development of heart disease. There are 2 types of sleep apnea: obstructive and central. Obstructive sleep apnea (OSA) affects an estimated 15 million adult Americans and is present in a large proportion of patients with high blood pressure, coronary artery disease, stroke, and atrial fibrillation. Central sleep apnea (CSA) is less common and occurs mainly in patients with heart failure.
Obstructive Sleep Apnea (OSA). OSA refers to repeatedly interrupted breathing during sleep caused by the collapse of the airway (tongue, palate and back of throat). An episode of OSA is characterized by a long pause in breathing (at least 10 seconds) associated with ongoing attempts to breathe. This results in a fall in the oxygen content of the blood and intermittent loud snoring. A diagnosis of OSA syndrome is made when a patient has more than 5 OSA episodes per hour during sleep and also experiences daytime sleepiness.
Central Sleep Apnea (CSA). CSA is characterized by repetitive stopping of breathing during sleep due to reduced signaling from the brain. It is also associated with daytime sleepiness, but not necessarily with snoring. An episode of CSA is characterized by a long pause in breathing (at least 10 seconds) without ongoing attempts to breathe. Generally, over 5 such events per hour during sleep are considered abnormal. Many patients with OSA have CSA as well.
Consequences of Sleep Apnea. During an episode of sleep apnea oxygen levels in the blood may drop severely. This can cause the blood vessels to constrict and blood pressure to rise. Indeed, in patients with OSA, blood pressure can reach levels as high as 240/130 mm Hg. The combination of low blood oxygen levels, constricted blood vessels and very high blood pressure can lead to heart rhythm abnormalities, heart attack, heart failure, and even sudden death.
Other effects of OSA. Patients with OSA are more likely to have poor blood sugar control, insulin resistance, a worse cholesterol profile, blood which is more likely to clot, and higher levels of inflammatory markers in the blood (associated with higher risk of heart attack).
Causes of OSA. Obesity is the single most important cause of OSA.
Treatment of OSA. Weight loss alone can lead to improved sleep efficiency, decreased snoring, and improved oxygenation. Other treatments include:
1. Using techniques to keep the patient sleeping on their side (such as sewing a tennis ball into the back of a pajama top).
2. Using a mask which forces air through the nose (such as CPAP (“continuous positive airway pressure”) or BIPAP (“bilevel positive airway pressure” – which adjusts the pressure of the air being delivered depending upon whether the patient is breathing in or breathing out). Both types of masks can be used with supplemental oxygen if necessary.
3. Using a mouth appliance which realigns the jaw and helps prevent airway collapse
4. Surgery to enlarge the airway or bypass the obstruction.
Guideline-Based Standards of Care: What You Should Know
The American College of Cardiology (ACC) and the American Heart Association (AHA) work together on an ongoing basis to publish Guidelines addressing standards of care for the diagnosis, management and prevention of cardiovascular disease. The ACC/AHA Guidelines represent a consensus of expert medical opinion, with the goal of establishing a standard on which to base cardiovascular care decisions, serving the patient’s best interests.
The guidelines are intended to help health care providers and patients make informed, best-possible decisions regarding care for specific clinical circumstances. The ACC strongly believes that adoption of these standards leads to higher quality cardiovascular care, cost-effectiveness, and most importantly, better outcomes for patients.
Please note that the ACC/AHA Guidelines attempt to define practices that meet the needs of most patients in most circumstances. However, everyone is unique, and the extent to which the guidelines apply specifically to you should be a key point of discussion between you and your cardiologist or health care provider. The ultimate judgment regarding your care must be made by you and your healthcare provider together, in light of circumstances specific to you as a patient.
Although all ACC/AHA Guideline documents are freely available, and can be downloaded from the ACC’s Cardiosource web site, these documents are often extremely long, and written primarily for the healthcare provider. Here at CardioSmart you will find a summary of the key points from the Guidelines, written specifically with the patient in mind. We urge you to review these key points, print them out if you like, and engage your healthcare provider in a discussion of how the guidelines relate to you and your condition.
That is, after all, what being CardioSmart is all about – being empowered to work with your physician in managing your care to assure the best possible outcome!
If you’d like to read the full guidelines from which this summary is derived, please go to http://www.cardiosource.com/cjrpicks/CJRPick.asp?cjrID=4476 or at http://content.onlinejacc.org/cgi/content/full/j.jacc.2008.05.002 . Please note that these documents are large, so please have patience while they load.
