How Does Sleep Apnea Affect the Heart? Risks, Warning Signs and When to Get Tested

Sleep apnea can affect much more than how rested you feel in the morning. When breathing repeatedly pauses or becomes restricted during the night, oxygen levels can fall and the body responds as though it’s under stress, which can cause sudden changes in heart rate and blood pressure. Changes like that make the cardiovascular system work harder while you’re supposed to be at rest.

When sleep apnea goes untreated, these episodes can continue night after night. Obstructive sleep apnea (OSA) is associated with cardiovascular problems including high blood pressure, abnormal heart rhythms, atrial fibrillation (AFib), heart failure and coronary artery disease.

Understanding the connection can help you recognize when poor sleep may be affecting more than your energy. Read on to learn how sleep apnea can affect the heart, what signs to watch for and when testing may make sense.

What Happens During Sleep Apnea?

Sleep apnea causes repeated interruptions in breathing while you sleep. The most common form is called obstructive sleep apnea (OSA), and it occurs when the upper airway becomes partially or completely blocked.

When this happens, airflow is reduced or stops even though the body is still trying to breathe. Oxygen levels may fall, and your brain eventually signals your body to reopen the airway. You may briefly wake or partially wake as breathing starts again without remembering it the next morning.

This cycle can happen repeatedly throughout the night.

Common signs of obstructive sleep apnea include:

• Loud, frequent snoring 
• Pauses in breathing noticed by someone else
• Waking up gasping or choking
• Frequent nighttime awakenings
• Morning headaches
• Feeling tired or sleepy during the day

Repeated breathing interruptions can also place stress on the heart and blood vessels.

How Sleep Apnea Puts Stress on the Heart

Sleep apnea affects the heart because breathing repeatedly stops or becomes very limited during sleep. When that happens, the body doesn’t get the steady supply of oxygen it normally expects. The brain senses that something is wrong and briefly puts the body into a stress response to get breathing started again.

During these episodes:

• Oxygen levels may drop
• Heart rate may rise or change
• Blood pressure may increase
• Blood vessels may tighten
• The heart may have to work harder

Once breathing starts again, the body begins to settle down. For people who suffer from sleep apnea, this cycle can repeat over and over throughout the night. Instead of getting hours of uninterrupted rest, the heart and blood vessels may be repeatedly pushed into a more active, stressed state. Over time, that repeated strain can contribute to problems with blood pressure, heart rhythm and overall heart health.

Can Sleep Apnea Damage Your Heart?

The repeated drops in oxygen, changes in heart rate and increases in blood pressure caused by sleep apnea can affect the cardiovascular system in several different ways. Over time, untreated sleep apnea has been associated with high blood pressure, abnormal heart rhythms and heart failure.

High Blood Pressure

Blood pressure can rise each time breathing is interrupted and the body enters a stress response. If it happens repeatedly throughout the night, it can contribute to higher blood pressure over time.

Sleep apnea may be especially important to investigate when high blood pressure remains difficult to control despite treatment.

Abnormal Heart Rhythms and Atrial Fibrillation

One rhythm problem with a particularly strong connection to sleep apnea is atrial fibrillation, or AFib. Sleep apnea is common among people with AFib, which is one reason a healthcare provider may consider sleep testing when AFib keeps returning or is difficult to manage.

Sleep apnea can affect the heart's normal rhythm. Repeated drops in oxygen and sudden stress responses during the night may contribute to episodes of a fast or irregular heartbeat.

You may notice:

• A racing heart at night
• Palpitations
• Irregular heartbeats
• Sudden changes in nighttime heart rate

Having sleep apnea doesn’t mean you will develop AFib, and an irregular heartbeat can have many other causes.

Heart Failure

Heart failure occurs when the heart cannot pump or fill well enough to meet the body's needs. Sleep apnea doesn’t necessarily cause heart failure, but repeated drops in oxygen, increases in blood pressure and extra nighttime strain can contribute to cardiovascular problems over time.

People with heart failure may also develop central sleep apnea, a different form of sleep apnea involving unstable breathing signals from the brain. Possible symptoms of heart failure can include:

• Shortness of breath
• Reduced ability to exercise
• Swelling in the legs or feet
• Waking up short of breath

These symptoms can have many different causes. New or worsening symptoms should be medically evaluated.

Sleep Apnea and Heart Attack Risk

Untreated sleep apnea is associated with a higher risk of cardiovascular disease, including heart attack. The concern comes from the way sleep apnea can add to several forms of cardiovascular stress at the same time.

Repeated apnea episodes may contribute to:

• Drops in nighttime oxygen
• Repeated increases in blood pressure
• Increased nervous-system activity
• Stress on blood vessels
• Inflammation and metabolic changes
• Greater strain on existing cardiovascular disease

NHLBI includes heart attack and coronary artery disease among the cardiovascular conditions associated with untreated sleep apnea. Sleep apnea may also be particularly important to address when someone already has other cardiovascular risk factors, including:

• High blood pressure
• High cholesterol
• Diabetes
• A history of smoking
• Obesity
• Existing heart or blood-vessel disease

If you have several risk factors, there may be more opportunities to reduce cardiovascular strain by identifying and managing the factors that can be treated. If you develop new or severe chest pain, major difficulty breathing or symptoms of a possible heart attack, call 911 rather than waiting for a routine sleep or cardiology appointment.

Warning Signs Sleep Apnea May Be Affecting More Than Your Sleep

Sleep apnea symptoms become especially important to explain to a healthcare provider when they occur alongside heart-related concerns.

An evaluation may be needed if you have sleep apnea symptoms such as loud snoring, gasping or pauses in breathing along with:

• High blood pressure that is difficult to control
• Repeated nighttime heart-rate spikes
• Palpitations or irregular heartbeats
• Known or recurrent atrial fibrillation
• Waking up short of breath
• Existing cardiovascular disease

These signs won’t prove that sleep apnea is damaging your heart, but they are still worth looking at both your sleep and cardiovascular health rather than treating the symptoms separately.

Sleep apnea is particularly important to consider in people with difficult-to-control high blood pressure or recurrent AFib, where screening may be appropriate.

Testing for Sleep Apnea

Evaluation for sleep apnea typically begins with a review of your sleep symptoms, medical history and other health conditions. Depending on the patient, testing may involve either an overnight sleep study in a sleep center or a home sleep apnea test.

Sleep testing can measure information such as:

• Breathing patterns
• Breathing effort
• Oxygen levels
• Heart rate
• Sleep patterns and awakenings

Home testing can be appropriate for certain adults suspected of having obstructive sleep apnea, while an in-lab sleep study may be preferred when medical history or other health conditions make more detailed monitoring necessary.

Can Heart Damage From Sleep Apnea Be Reversed?

Some of the strain sleep apnea places on the heart and blood vessels may improve with effective treatment. However, whether existing heart damage can fully reverse depends on the type of heart problem, how severe it is and how long it has been present.

Treating sleep apnea can reduce the repeated breathing interruptions and drops in oxygen that place stress on the body throughout the night. When treatment is effective, it may help:

• Keep oxygen levels more stable during sleep
• Reduce repeated nighttime stress responses
• Improve sleep quality
• Reduce some of the strain placed on the heart and blood vessels
• Help with blood pressure control in some people
• Reduce heart-rate changes related to breathing interruptions

Sleep apnea treatment will depend on the type and severity of the condition as well as your overall health and anatomy. Options can include:

• CPAP or another positive-airway-pressure device
• An oral appliance in appropriate patients
• Weight management when appropriate
• Addressing contributing airway problems
• Lifestyle changes
• Other individualized treatments

Treatment is aimed at reducing breathing interruptions and helping your body maintain more stable airflow and oxygen levels throughout the night.

For people who also have cardiovascular concerns, treating sleep apnea is only one part of protecting heart health. Blood pressure, cholesterol, diabetes, abnormal heart rhythms and other existing heart conditions may still need their own treatment and monitoring. Managing both sleep apnea and cardiovascular risk factors can help reduce ongoing strain on the heart and support better overall health.

When to See a Sleep Specialist or Cardiologist in Queens or Brooklyn

If you regularly stop breathing, gasp or choke while sleeping, or struggle with significant daytime tiredness despite spending enough time in bed, it’s worth finding out whether sleep apnea may be involved.

Evaluation may be especially important if those symptoms occur alongside:

• High blood pressure that is difficult to control
• Repeated nighttime heart-rate spikes
• Palpitations or irregular heart rhythms
• Atrial fibrillation
• Known cardiovascular disease
• Waking up short of breath
• Other new or unexplained heart-related symptoms

At Advanced Medical Care, our cardiology and sleep medicine teams help patients throughout Queens and Brooklyn understand how sleep and heart health may be affecting one another. With both specialties available, we can look at the bigger picture and help determine whether sleep apnea, a cardiovascular condition or a combination of factors may need further evaluation.

Advanced Medical Care provides care in Forest Hills, Queens and Brighton Beach, Brooklyn. If you are concerned about symptoms of sleep apnea or how your sleep may be affecting your heart, we are here to help you better understand what may be happening and what next steps make sense. Please call us at 347-571-9389 (Queens) or 929-552-2973 (Brooklyn) to schedule an appointment, or book online to get started.

Routine sleep and cardiology appointments are not a substitute for emergency care. Call 911 if you are experiencing severe or new chest pain, major difficulty breathing, fainting, signs of a stroke or symptoms of a possible heart attack.

Frequently Asked Questions About Sleep Apnea and Heart Health

Does sleep apnea put stress on your heart?

Yes. During sleep-apnea episodes, oxygen levels can fall while the nervous system activates the body's stress response. This can cause repeated changes in heart rate and blood pressure and place additional strain on the cardiovascular system throughout the night.

Can sleep apnea cause an irregular heartbeat?

Sleep apnea is associated with abnormal heart rhythms. Repeated changes in oxygen levels and nervous-system activity may affect heart rhythm in susceptible people, although an irregular heartbeat can have many different causes.

Can sleep apnea cause atrial fibrillation?

Obstructive sleep apnea is strongly associated with atrial fibrillation and is common among people with AFib. However, those with sleep apnea will not always develop AFib, but sleep apnea is an important condition to consider when AFib is recurrent or difficult to manage.

Can sleep apnea contribute to heart failure?

Sleep apnea may contribute to cardiovascular strain through repeated oxygen drops, blood-pressure changes and increased nervous-system activity. Sleep-disordered breathing is also common among people who already have heart failure, so the two conditions can sometimes affect one another.

Can sleep apnea cause a heart attack?

Untreated sleep apnea is associated with cardiovascular disease and heart-attack risk, but sleep apnea does not directly cause heart attacks. Its effects can add to other cardiovascular risks such as high blood pressure, diabetes, smoking, high cholesterol and existing heart disease.

Should someone with heart problems be tested for sleep apnea?

Testing may be appropriate when someone with cardiovascular disease also has symptoms or risk factors for sleep apnea. Sleep apnea is particularly important to consider in people with difficult-to-control high blood pressure, recurrent AFib, heart failure or nighttime cardiovascular symptoms.