If you suffer from untreated sleep apnea, a momentary stop of breathing occurring repeatedly while you sleep, you could be causing serious damage to your heart.
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“It’s likely that sleep apnea can cause arrhythmias and heart failure because if you have sleep apnea, you tend to have higher blood pressure,” explains molecular cardiologist David Van Wagoner, PhD.
Importantly, sleep apnea occurs in about 50 percent of people with heart failure or atrial fibrillation, the latter the most common sustained abnormal heart rhythm.
“There is a very strong association between sleep apnea and cardiac arrhythmia. Research also shows episodes of upper airway collapse in sleep apnea may trigger arrhythmia events,” says Reena Mehra, MD, Director of Sleep Disorders Research in the Sleep Center of the Neurologic Institute at Cleveland Clinic.
Other ways that sleep apnea can increase risk of arrhythmias and heart failure include:
- Repeated episodes of oxygen lowering (what doctors call hypoxia)
- Changes in carbon dioxide levels
- Direct effects on the heart due to pressure changes within the chest
- Increased levels of markers of inflammation
What happens when you stop breathing
When you stop breathing, your heart rate also tends to drop the longer your body is deprived of oxygen. Then, your involuntary reflexes cause you to startle awake at the end of that period of not breathing. When this occurs, your heart rate tends to accelerate quickly and your blood pressure rises.
These are changes that take place acutely when you stop breathing. However, your body starts to experience chronic effects if you experience frequent sleep apnea. Data suggests increased risk, particularly when you stop breathing roughly 30 times or more per hour. Dr. Van Wagoner says there is likely a risk at even lower frequency rates.
For example, your blood pressure tends to go up, your heart walls thicken due to increased workload and the structure of your heart changes. It tends to become stiffer and less flexible because there are more fibrous cells growing in between the muscle cells.
“All of those things increase the risk that you can have either atrial or ventricular arrhythmias,” Dr. Van Wagoner says. “They also tend to reduce the function of the heart so that it’s less efficient at pumping blood.”
Two types of sleep apnea
Sleep apnea can be categorized into two types:
- Obstructive sleep apnea occurs when an obstruction of your airway results in the inability to breathe normally during sleep. This form of the disorder is primarily associated with obesity and also more common in men and with increasing age. There are also likely genetic factors at play involving control of breathing that are independent of obesity.
- Central sleep apnea occurs when your brain does not send the proper signals to the muscles that control breathing. “This form of the disorder is less common and less well understood, but it happens frequently in relationship to heart failure or stroke,” says Dr. Van Wagoner.
How to know you have a problem
Most often, it’s your spouse who will notice that you are snoring heavily and having periods where you stop breathing or wake up abruptly with shortness of breath. Here are some additional symptoms Dr. Mehra says you might notice if you have sleep apnea:
- Excessive daytime sleepiness
- Restless sleep
- Observed or witnessed episodes of stopping breathing during sleep
- Awakening with the urge to urinate
- Difficulty maintaining continuous sleep
- Morning headaches
- Difficulty concentrating and mood shifts
Some ways to control sleep apnea include:
- Use CPAP or continuous positive airway pressure. This is the standard treatment for sleep apnea at this time. It involves a mask a person wears over the nose and/or mouth while sleeping. A machine gently pushes air through the mask to keep the airway from closing and, as a result, prevents intermittent oxygen lowering and rises in blood pressure.
- Lose weight by eating a more nutritious diet, reducing caloric intake and exercising regularly if you are overweight or obese. After weight loss occurs, talk to your doctor about a repeat assessment of your sleep apnea.
- See your doctor about apnea symptoms. “The most important thing to do, if you have any of those symptoms, is to see your physician immediately,” Dr. Mehra says. “Heavy snoring and daytime sleepiness are good clues for obstructive sleep apnea, but you usually need to talk to a sleep specialist or have a sleep study performed to properly diagnose the condition.”
“It is important to note that typical obstructive sleep apnea symptoms such as daytime sleepiness are sometimes absent in heart failure. Also, symptoms of central sleep apnea are oftentimes more difficult to detect,” Dr. Mehra says.
With the high prevalence of sleep apnea in cardiac arrhythmias and heart failure (essentially a coin flip as to whether the patient has it), experts recommend that you don’t delay in seeking the advice of your physician.