Arrhythmia puts you at greater risk of potentially life threatening complications affecting your heart, brain, and lungs.

An arrhythmia is an abnormal heartbeat that beats too fast, slow, or erratically. Although arrhythmias are often harmless, they can weaken your heart muscle and prevent sufficient blood flow to the rest of your body.

Complications may vary based on the type of arrhythmia. These types include:

Arrhythmias that affect your heart’s ventricles (the lower chambers) rather than the atria (the upper chambers) are the most dangerous. But atrial arrhythmias can also lead to potentially life threatening complications.

Keep reading to learn about the common complications of arrhythmia, when to see a doctor, and how to help stop complications from occurring.

Some arrhythmias may lead to serious heart complications, such as heart failure or cardiac arrest.

Heart failure

Heart failure, sometimes referred to as congestive heart failure, can occur if your heart cannot pump enough blood to the rest of your body.

Because it prevents your heart from pumping blood effectively, an arrhythmia, especially an AFib, may cause heart failure. Irregular, rapid heartbeats due to AFib can weaken your heart muscle.

Conversely, heart failure may also lead to arrhythmia.

Cardiac arrest

The most common cause of cardiac arrest, a life threatening condition where your heart suddenly stops beating, is ventricular fibrillation (VF). Nearly 70% of people who experience cardiac arrest have a VF.

VF can lead to cardiac arrest because it makes the lower chambers in your heart quiver instead of beating normally. Your heart may collapse because it’s unable to pump blood.

Some types of V-tach, like pulseless V-tach, are also common causes of cardiac arrest. This occurs because the heart beats so quickly the ventricles don’t have enough time to fill with blood, stopping blood flow.

Arrhythmia can lead to an insufficient supply of blood to your brain. This makes it a risk factor for conditions, like stroke and dementia. AFib is the arrhythmia most closely linked to brain complications.

Stroke

AFib causes about 20% of ischemic strokes, the most common type of stroke. Ischemic strokes result from a blockage in a blood vessel that carries blood to your brain.

The irregular contractions of your atria due to AFib may result in blood pooling in your heart’s chambers. The pooled blood may clot, and pieces of clotted blood can travel through your bloodstream from your heart to your brain, causing a stroke.

Dementia

Research shows a correlation between AFib and cognitive decline. Although there’s no evidence AFib is a direct cause of dementia, it may increase the risk.

A large 2023 study of nearly 200,000 people suggests AFib moderately increases the risk of dementia in adults younger than 65 and adults who don’t also have chronic kidney disease.

Another large 2023 study of over 433,000 United Kingdom Biobank participants suggests those who received an AFib diagnosis before age 65 had a higher risk of developing dementia and Alzheimer’s disease.

Strokes that are a complication of AFib are among the risk factors that may lead to dementia.

In addition to heart and brain complications, arrhythmia may be a risk factor for developing a pulmonary embolism (PE), a blood clot in your lung.

PEs are usually due to a deep vein thrombosis (DVT), a condition in which a blood clot forms inside a vein deep in your body, typically in your lower leg or thigh.

A 2018 study concluded the risk of developing a PE substantially increased within the first 6 months after an AFib diagnosis.

A PE may also lead to arrhythmia.

You should contact a doctor if your arrhythmia symptoms are getting worse or if you notice new symptoms. Arrhythmia symptoms include the following:

Among the ways to help prevent arrhythmia complications are to maintain a healthy lifestyle and avoid triggers by doing the following:

If you have a pacemaker or implantable cardioverter defibrillator (ICD), avoid participating in contact sports that could dislodge it.

Check with a doctor before taking over-the-counter cold and allergy medications, nutritional supplements, or other medications.

Medications and procedures, like cardioversion, can help you manage your arrhythmia and prevent complications. Talk with a doctor about the best treatment options for your particular type of arrhythmia.

When should I be worried about an irregular heartbeat?

If your irregular heartbeat is only temporary, be aware of what may have triggered it, such as anxiety, caffeine, or smoking. Try to avoid these triggers to help prevent heart palpitations.

Should your irregular heartbeat persist, or if it recurs after you’ve avoided any known triggers, see a doctor to determine the cause.

You should also see a doctor if you have an irregular heartbeat along with a condition, such as diabetes, coronary artery disease, or high blood pressure.

What is the best treatment for an irregular heartbeat?

The best treatment for an irregular heartbeat depends on factors, including the type and severity of arrhythmia and other health conditions you may have.

Typical treatment options for arrhythmia include:

  • making healthy lifestyle changes
  • taking medications, including beta-blockers and calcium channel blockers
  • undergoing procedures, such as cardioversion, which resets your heart’s rhythm using electrical shocks, or catheter ablation, which blocks your heart’s abnormal electrical signals
  • receiving an implantable device, such as a pacemaker or ICD, that controls your heart rate

What are fatal arrhythmia symptoms?

If you have an arrhythmia diagnosis, get immediate medical treatment if you experience any of these potentially life threatening symptoms:

Complications of arrhythmia, such as stroke and cardiac arrest, can be life threatening. It’s important to manage your arrhythmia with treatments that may include healthy lifestyle changes, medications, and medical procedures to help prevent complications from developing.

A doctor can help determine the most effective treatment plan for your type of arrhythmia.

If you have arrhythmia and are experiencing symptoms, such as chest pain or fainting, get immediate medical help.