Obstructive Sleep Apnea and Heart Disease

Obstructive sleep apnea (OSA) is a condition in which you stop breathing during sleep because of a narrowed or closed breathing passage (airway). Adults with obstructive sleep apnea are more likely to be overweight. Common symptoms of obstruc- tive sleep apnea include snoring, stopping breathing during sleep, frequent awakenings during the night and difficulty staying asleep throughout the night. It is also common for patients who have obstructive sleep apnea to be tired and sleepy during the day. Obstructive sleep apnea can also have a bad effect on your heart and your blood vessels (arteries, veins and capillaries), which is also referred to as the cardiovascular system. In addition, this sleepiness can cause accidents at work, poor work performance and car crashes.

What kinds of cardiovascular problems can I get with obstructive sleep apnea?

Several cardiovascular conditions can happen with untreated obstructive sleep apnea. For example, if you have obstructive sleep apnea, you are more likely to have high blood pressure (hypertension) or it may be difficult to control your blood pressure. Of people with hypertension, about 30% have obstructive sleep apnea. If you have obstructive sleep apnea, there is a 50% chance you also have hypertension.

Problems with the rhythm of your heart may occur such as atrial fibrillation (irregular heart beat) and bradycardia (slow heart rate). Patients with severe obstructive sleep apnea are four times more likely to have atrial fibrillation compared to those without the disorder. Not receiving treatment for your sleep apnea may make your atrial fibrillation difficult to control. For example, in patients who have atrial fibrillation cured with catheter ablation (a special treatment to the heart), those with untreated obstructive sleep apnea are 25% more likely to have their atrial fibrillation return.

Patients with obstructive sleep apnea are also more likely to have coronary artery disease. Coronary artery disease (also known as the hardening of the arteries) happens when the small blood vessels that supply blood and oxygen to your heart become narrow.

Narrowed coronary arteries can lead to heart attacks. If you have severe obstructive sleep apnea that is untreated, you are twice as likely to devel- op heart attacks in the future as those without the problem. In addition, up to 70% of patients admitted to the hospital because of coronary artery disease were found to have sleep apnea. If you have heart failure, obstructive sleep apnea can make it worse.

Also, people with untreated obstructive sleep apnea can develop heart failure. The chance of having obstructive sleep apnea if you have heart failure is quite high.

How does obstructive sleep apnea cause heart disease?

The reason why patients with obstructive sleep apnea develop heart disease is not exactly known. Obstructive sleep apnea causes you to have frequent pauses in your breathing; these pauses mean that you actually stop breathing and this causes you to wake up at night. When these breathing pauses happen, the oxygen level in your blood gets low. It is thought that the frequent bouts of low oxygen levels during sleep damages the blood vessels that supply the heart. Also with each one of the episodes, your body tells your heart to beat faster and your blood pressure to go up. Severe obstructive sleep apnea can also cause stress on your heart causing the heart to get enlarged. An enlarged heart can cause the heart to get less oxygen and work less efficiently.

Tests to detect sleep apnea include:

• Polysomnogram (PSG): this is a comprehensive over- night sleep study that is performed in a sleep center under the supervision of a licensed polysomnographic sleep technologist. It is the preferred sleep study for patients with other medical problems, such as, cardiovas- cular disease, obstructive pulmonary disease (COPD), neuromuscular diseases and/or cognitive disorders. A PSG can accurately determine the number of pauses in breathing (apnea / ap·ne·a) and episodes of abnormally slow or shallow breathing (hypopnea / hy·po·pne·a), key factors that determine if a patient is positive or negative for sleep apnea. A PSG can also diagnose up to 80 sleep disorders by using a variety of equipment that monitors brain activity, eye movements, respiratory effort, blood oxygen saturation, heart rate, body movements, and more. 
• Home Sleep Test (HSAT): this is a sleep study used only for the diagno- sis of sleep apnea and is performed by patients themselves in their home. HSTs are limited in the data they capture to respiratory effort, blood oxygen saturation, and airflow. HSTs may not accurately deter- mine when the patient is awake or asleep and what stage of sleep the patient is in. As a result, a HST may not be conclusive in determining if a patient is positive or negative for sleep apnea.

What happens if my sleep study results are positive for sleep apnea? You should expect your study results in up to 15 business days from the time your sleep study was completed. The physician that ordered your sleep study will be calling to inform you of your study results. Otherwise, you should expect a telephone call from our sleep specialist to schedule a follow-up care consultation, only if your study results are positive and requested by the physician that ordered your sleep study. During a follow-up care consultation your treatment options will be discussed.

To schedule an appointment at one of Inspira Health's Sleep Centers near you, call (856)–853–2131

References: American Heart Association, Harvard Healthy Sleep, Sleep Foundation