What Is Arrhythmia?

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An arrhythmia is an irregular heartbeat caused by an abnormal heart rate or heart rhythm. Heart rate is the number of times your heart beats in one minute while at rest, while heart rhythm is the pattern of electrical impulses that squeeze and pump your heart. Together, your heart rate and heart rhythm pump blood throughout your body.

If you have an arrhythmia, your heart cannot pump blood efficiently. This can lead to symptoms like fainting and dizziness and can increase your risk of more serious complications.

There are many types of arrhythmias. However, understanding common symptoms can help you know when to reach out to a healthcare provider for testing. Treatment can reduce your risk of complications, as can taking preventative measures.

Types of Arrhythmias

Your heart is divided into four chambers. The upper two chambers (right and left atria) pump blood into the lower two chambers (right and left ventricles), which then pump blood throughout the rest of your body.

Arrhythmias are often divided into two categories: ventricular and supraventricular. They can also be classified as either bradyarrhythmias (heart rate lower than 60 beats per minute, or bpm) or tachyarrhythmias (heart rate higher than 100 bpm).

Supraventricular Arrhythmias

Supraventricular arrhythmias originate above the ventricles, either in the atria or in the gateway to the ventricles.

  • Atrial fibrillation: Also known as AFib or AF, this is the most common type of arrhythmia. It affects about 2.5 million people in the United States. The atria beat irregularly, up to 400 bpm, which causes blood to pool. As a result, your heart cannot pump enough blood to your body. The pooling blood can also create blood clots, which can travel to the brain and block arteries, causing a stroke.
  • Atrial flutter: This is the second most common type of arrhythmia. The upper two chambers of your heart start beating rapidly, up to 250 to 350 bpm, and might not be coordinated. This can happen when damaged or scarred tissue blocks the signal that tells the atria to beat.

Ventricular Arrhythmias

Ventricular arrhythmias originate in the ventricles. These arrhythmias require immediate medical attention.

  • Ventricular fibrillation: This is the most serious arrhythmia. The ventricles start to contract irregularly, which prevents the heart from pumping blood to your body. Ventricular fibrillation can cause sudden cardiac arrest and requires immediate medical treatment.
  • Ventricular tachycardia: With this type of arrhythmia, the ventricles start beating too quickly. While this is fine for a few seconds, it can be serious if it lasts longer. Ventricular tachycardia can develop after a heart attack or in people with heart disease.

Other Arrhythmias

Arrhythmias include many conditions, including:

  • Bradycardia: This is generally diagnosed when your resting heart rate is lower than 60 bpm. Heart rate naturally drops during sleep, and bradycardia can be common in young people and people who regularly engage in more intense exercise. However, it can lead to serious complications if you experience other symptoms, such as fatigue, confusion, and dizziness.
  • Tachycardia: This is a resting heart rate above 100 bpm. You might not experience any symptoms, but they can include fainting, lightheadedness, and heart palpitations (feeling like your heart is fluttering or pounding).
  • Conduction disorders: In conduction disorders, the electrical impulse that travels through the heart gets blocked, forcing the impulse to take a different path. Conduction disorders include bundle branch block (one ventricle contracts slightly slower than the other) and different types of heart block (a signal delay between the atria and ventricles).
  • Premature contractions: In premature contractions, the heart chambers start to contract before the blood fills them. Premature contractions can affect both the upper and lower chambers of your heart and cause irregular heartbeats.
  • Sinus arrhythmias: Sinus arrhythmia is a normal condition in which your heart rate changes as you breathe. Your heart rate increases by several beats as you inhale and decreases when you exhale.

Other arrhythmias include:

  • Wolff Parkinson's White syndrome (WPW): A malfunction of electrical pathways between the atria and ventricles
  • Adam-Stokes disease: An interruption of the heart's electrical signals between the atria and ventricles
  • Sick sinus syndrome: An arrhythmia that affects the sinoatrial or sinus node, the natural pacemaker that initiates the heart's electrical impulse

Arrhythmias in Children

Children can also experience arrhythmias, including those listed above. Other types include:

  • Long QT Syndrome (LQTS): This is caused by a problem with the heart's electrical activity. The ventricles of the heart take longer to relax, so they remain contracted for a longer period of time. Symptoms of LQTS include fainting, seizures, and an irregular heart rate.
  • Premature contractions: These can occur in children with normal heart structures. They occur in either the upper or the lower chamber of the heart. The child often complains that their heart skipped a beat.
  • Complete heart block: This type of arrhythmia can be caused by medications, disease, or surgery. It can also be congenital, meaning you're born with it.

Here are some recommendations if your child has an arrhythmia:

  • Know how to check your child's heart rate and rhythm if they have an arrhythmia. These can be measured by checking your child's pulse.
  • If your child is taking medications for arrhythmias, be sure to give the medications at the proper time. Some medications need to be given at regular intervals.
  • Learn CPR and other emergency techniques, which can help save a child's life in case of a cardiac emergency.

Arrhythmia Symptoms

Arrhythmias can cause a range of symptoms in some people, while others may not experience any symptoms at all. Heart palpitations are often the main symptom. It might feel like your heart is racing, fluttering, or pounding.

Here are some other common symptoms you might experience in arrhythmias:

  • Change in heartbeat, either faster or slower than usual, or irregular
  • Dizziness and lightheadedness
  • Chest pain
  • Sweating, especially if you feel anxious
  • Fainting or near-fainting
  • Shortness of breath

Causes and Risk Factors

Your heart rate and rhythm can be influenced by many factors, including previous heart attacks, smoking, and stress.

Here are some possible causes of arrhythmias:

  • A conduction problem: Anything that blocks your heart's electrical conduction pathways can lead to arrhythmia.
  • Sinus node change: The sinoatrial or sinus node is your heart's natural pacemaker. It sends a steady rhythm of electrical impulses to make your heart beat. A change in the sinus node can cause abnormal heart activity.
  • Medications: Medications like antibiotics and some cold medications can contribute to arrhythmia.
  • Electrolyte and hormonal imbalances: Changes in hormone and electrolyte levels in your blood can contribute to arrhythmias, especially changes in thyroid hormone levels that can affect your heart.
  • Infections: Certain viral infections can affect your heart rate and rhythm, including COVID-19 and influenza.

Risk factors for arrhythmias include:

  • Older age
  • A family history of arrhythmia
  • Lifestyle habits, including smoking and drinking more than the recommended daily limit of alcohol (one drink per day for people assigned female at birth, two drinks for people assigned male at birth)
  • Health conditions, including heart, lung, and kidney disease, as well as sleep apnea and obesity


Your healthcare provider will diagnose your arrhythmia based on your clinical history, a physical exam, and an electrocardiogram (EKG or ECG). An electrocardiogram measures the electrical activity of your heart. Every time your heart beats, an electrical impulse travels through your heart's four chambers and allows your heart to contract in proper rhythm so that blood can travel to other parts of your body.

Your healthcare provider will likely do multiple tests based on factors that can affect your heart. These include:

  • Blood tests to check potassium, thyroid hormones, and electrolyte levels
  • Genetic testing
  • Heart imaging tests, such as an MRI, which show structural abnormalities of your heart
  • An electrophysiology study (EPS), which measures the electrical activity of your heart

In some cases, your healthcare provider might recommend long-term monitoring of your heart's electrical activity. You might wear a Holter monitor or have an implantable loop recorder under your skin.

Possible Complications

Arrhythmias can lead to many complications. More severe complications are either due to blood clots or a lack of blood supply to major organs, like the brain.

Some of the most common complications of arrhythmias include,

  • Stroke: Quivering in the heart causes blood to pool in the chambers. This can lead to blood clots, which can block arteries in your brain, leading to a stroke.
  • Cardiac arrest: Arrhythmia can cause the heart to suddenly stop beating, leading to cardiac arrest.
  • Heart failure: When you have multiple arrhythmias, you can develop cardiomyopathy, which is a problem with your heart muscle. As the heart muscle stiffens, it's unable to pump blood to the rest of the body. This can lead to heart failure.
  • Altered brain function: An arrhythmia can decrease the blood supply to your brain, which can affect brain functioning.


Understanding the risk factors can help prevent future arrhythmia episodes. Here are some prevention strategies:

  • Monitor your pulse: Knowing how to take your pulse can help you recognize abnormalities.
  • Avoid triggers: Smoking, alcohol, and the use of illicit drugs are known to increase the risk of arrhythmias.
  • Take medications as prescribed: Many medications, including some used for heart disease, can trigger abnormal heartbeats. Always take medication as prescribed by your healthcare provider.
  • Make lifestyle changes: Eating a healthy diet and regular exercise can help prevent and manage arrhythmias.
  • Lose weight: Excess weight gain can affect heart health.
  • Maintain healthy blood pressure and cholesterol: High blood pressure and cholesterol are considered risk factors for arrhythmia.

Arrhythmia Treatment

Treatment for arrhythmia depends on the causes, as well as possible future complications.

Your healthcare provider may prescribe one or more medications to manage your symptoms. For instance, atropine might be used to slow heartbeats, while beta-blockers, calcium channel blockers, and digoxin are among the medications that may be used to decrease high heart rates. High doses of medications that help manage arrhythmia can actually make your arrhythmia worse, so always take medications as prescribed by your healthcare provider.

Treatment might also include surgical methods, including cardioversion and catheter ablation. These procedures record your heart's activity and send electrical shocks as needed to restore a normal heart rhythm.

An implantable device is another common treatment for arrhythmia. These devices, including implantable cardioverter defibrillators (ICDs) and pacemakers, continually monitor and help restore your heart's regular rate and rhythm with electrical shocks. You might use them short-term or long-term depending on the condition and the cause of the arrhythmia.

Living with Arrhythmia

Arrhythmias, or irregular heartbeats, occur when a problem with the electrical activity of the heart causes changes in your heart rate or rhythm. Symptoms might include chest pain, sweating, and fainting.

Arrhythmias can be caused by various factors, but you can manage arrhythmia and prevent further episodes through medical treatment and lifestyle changes.

Always reach out to a healthcare provider if you start experiencing consistent irregular heartbeats. They can evaluate your symptoms, perform tests to determine underlying causes, and recommend treatment.

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22 Sources
Health.com uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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