Just like the steady, consistent drumbeat of your favorite song, your heart relies on a regular rhythm to work most effectively. When your heart consistently beats out of rhythm (known as an arrhythmia), a number of health concerns can occur.
While you may notice when your heart skips a beat or two while awake, you may be less likely to notice while you’re asleep.
Researchers have connected a number of heart rhythm disorders with the condition sleep apnea, a sleep breathing disorder.
Obstructive sleep apnea (OSA) is a sleep-related breathing disorder where your usual breathing is disrupted. While the interruption may be relatively brief, the pause (and the other frequent pauses that tend to occur with it) can have effects on your heart.
An estimated 25% of people who use a pacemaker to maintain a regular heart rhythm also have sleep apnea. This suggests there may be a close relationship between sleep apnea and arrhythmias.
Treating sleep apnea has also helped reverse or reduce the incidence of arrhythmias, which means that sleep apnea is a likely cause of arrhythmia in some people.
People with heart disease also experience sleep apnea in greater proportions. This means it’s likely that some people with sleep apnea may have already had some heart problems. Sleep apnea can worsen this damage which can further increase someone’s risk of abnormal heart rhythms.
What’s the most common heart arrhythmia during sleep apnea?
Slow heart rhythms — or bradyarrhythmias — are the most common for people with sleep apnea. The more severe your sleep apnea, the more likely you may have bradyarrhythmia.
But other arrhythmias can occur. For example, the risk of atrial fibrillation is 2 times as high for people with sleep apnea.
There are several potential causes related to sleep apnea that may lead to someone experiencing an arrhythmia during sleep.
Creating intrathoracic pressure changes
When you stop breathing during a sleep apnea episode, it’s like trying to drink from a straw that has something blocking it. When you try harder to drink from the straw, you start to generate extra pressure — but the drink still goes nowhere.
This effect is similar to what happens when you try to breathe when your airway is obstructed.
The intrathoracic pressure affecting your lungs and heart changes from its norm. These changes can potentially affect how blood flows back to the heart, as well as trigger and move the heart. Each of these changes may lead to an arrhythmia.
Triggering sympathetic and parasympathetic systems
When you stop breathing, it can trigger some of your body’s “backup” systems to stimulate breathing again. These systems could include the parasympathetic system which slows heart rate, or the sympathetic system which speeds the heart up.
Causing myocardial ischemia
When you stop breathing during a sleep apnea episode, your oxygen can drop. This could lead to hypoxia — when there’s a lack of oxygen to your tissues.
Hypoxia is a supply-and-demand concern. The heart demands oxygen, but there isn’t enough of a supply. Not enough oxygen to the heart is a condition known as myocardial ischemia, which can lead to developing arrhythmia.
Episodes of sleep apnea can affect your heart’s ability to receive oxygen. At first, your body tries to compensate in a number of ways.
It may try to make the heart beat faster or stronger in an attempt to get more oxygenated blood. Over time, this can cause the heart muscles to become larger or worn out, affecting overall heart function.
Also, a lack of oxygen can potentially damage your heart’s cells. This can lead to scarred and thicker areas that don’t move electrical activity through as well.
Some researchers consider the relationship between sleep apnea and heart failure “bi-directional.” This means sleep apnea and heart failure can worsen each other.
If sleep apnea is left untreated, it can cause chronic changes to your heart like scarring or fibrosis due to a lack of oxygen.
The heart’s electrical signals can’t move through the heart tissue as effectively. As a result, cardiac arrhythmias can occur more frequently.
Ideally, your doctor would test you for sleep apnea before you experience significant changes to your heart. Some risk factors for developing sleep apnea include:
- older age
- a history of waking up “unrefreshed” or feeling as if you haven’t slept
- male gender
- obesity
- wider neck circumference
If a partner reports that you snore or stop breathing during your sleep, this may indicate sleep apnea. Reach out to a doctor if you’re concerned you may have sleep apnea.
By screening for sleep apnea risk factors, a doctor may be able to recommend treatments at an earlier stage.
But it’s possible your doctor may detect an arrhythmia before diagnosing sleep apnea.
You may have symptoms of arrhythmias such as feeling as if your heart is skipping a beat or feeling faint. These symptoms may suggest your heart isn’t beating in an expected rhythm.
If a heart arrhythmia could be related to sleep apnea, it’s important to treat both conditions, not just one or the other.
Untreated sleep apnea can actually make anti-arrhythmic medications less effective. And if you’re doing certain treatments — such as ablation for atrial fibrillation — not treating your sleep apnea can increase your chances of the atrial fibrillation coming back.
The ability to reverse heart damage from sleep apnea depends on how severe the damage is.
Treating sleep apnea with a continuous positive airway pressure (CPAP) machine may help reduce arrhythmias by improving your oxygen supply while you sleep. This device helps keep your airways from collapsing to improve oxygen levels.
If the changes to your heart are not severe, some research suggests sleep apnea-related heart changes may be reversible by using a CPAP machine.
But research in 2021 suggests people with moderate to severe sleep apnea didn’t find that using a CPAP reduced the incidence of atrial fibrillation.
While CPAP machines are the gold standard for sleep apnea treatment, other treatments exist. They include upper airway surgery or wearing oral appliances to help properly position the tongue while sleeping.
It’s not currently known if these interventions are effective at reversing sleep apnea-related damage. Still, while they may not be able to reverse damage to the heart in all cases, it’s important to continue with sleep apnea treatments to prevent other life threatening symptoms.
Sleep apnea can do more than keep you from sleeping well at night. Some research suggests a link between sleep apnea and developing abnormal heart rhythms, which is another reason to treat sleep apnea.
Because arrhythmias can increase risk of early death, treating abnormal heart rhythms and sleep apnea can help keep your heart as healthy as possible.
Talk with a doctor about the best ways for you to treat your sleep apnea and keep your heart rate steady.