Understanding Arrhythmias and Heart Rhythm Disorders

An arrhythmia is a problem with your heartbeat. Your heart might beat too fast, too slow, or out of rhythm. Some heart rhythm problems are harmless, and some can be life-threatening. It’s important to know:

  • Heart rhythm problems are very common in the U.S.
  • If not treated, arrhythmias can lead to stroke, heart failure or sudden cardiac arrest.
  • They happen when there is a problem with the heart’s electrical system or its structure.

What are arrhythmias?

An arrhythmia is a problem with the rate or rhythm of your heartbeat.

Your heart is a pump that delivers blood to the rest of your body. Electrical signals control the rate and rhythm of your heartbeat. These signals travel on special pathways through the heart. Sometimes the electrical system goes wrong, or heart damage blocks these pathways.

It’s useful to know:

  • Heartbeat: A pumping action that takes about a second.
  • Heart rate: The number of times the heart beats in a minute. It’s normal for your heart rate to go up when you exercise and slow down when you sleep.
    • Bradycardia: A slow heart rate, usually fewer than 60 beats per minute.
    • Tachycardia: A heart rate more than 100 beats per minute
  • Heart rhythm: The pattern in which the heart beats.

Who gets heart rhythm problems

More than 14 million people in the U.S. have heart rhythm disorders, according to the Heart Rhythm Society.

Atrial fibrillation is the most common heart rhythm disorder. It affects up to 12 million people in the U.S., according to the Centers for Disease Control and Prevention.

About 300,000 people in the U.S. die each year from ventricular tachycardia or ventricular fibrillation.

Risk Factors

Age: Chances of having heart rhythm problems increase as you get older.

Family history and genetics: Your risk of arrhythmia increases if you have an inherited heart disease or a close relative who has had an arrhythmia.

Other heart diseases: Cardiomyopathy, heart failure, coronary artery disease and heart valve disease raise your risk for arrhythmia.

Other medical conditions: High blood pressure, diabetes, kidney disease, lung diseases, sleep apnea, thyroid conditions and more raise your risk for heart rhythm problems.

Lifestyle choices: Smoking, drinking lots of coffee or alcohol, and using cocaine or methamphetamines increase your risk.


Not all arrhythmias cause symptoms. If you have symptoms, they may include:

  • Palpitations (fluttery heart beats or feeling like your heart missed a beat)
  • Feeling that you might pass out
  • Passing out or fainting
  • Dizziness
  • Shortness of breath
  • Chest pain
  • Sweating
  • Weakness and extreme tiredness

Screening and prevention

Your provider may suggest screening tests based on your age, family history and heart health. These include:

  • EKG: A test to record your heart’s electrical activity.
  • Imaging tests to look for scars or damage in the heart.
  • Genetic testing if a family member had an arrhythmia or if you have a history of fainting.

To lower your risk, your provider may recommend lifestyle changes:

  • Stop smoking
  • Cut down on caffeine and alcohol
  • Manage stress
  • Exercise
  • Weight loss
  • Eat a heart healthy diet

Types of arrhythmia

Arrhythmias are defined in two ways:

  • Heartbeat problem, such as too fast (tachycardia) or too slow (bradycardia).
  • Where they start, such as the heart’s upper chambers (atria) or lower chambers (ventricles).

Heart rhythm disorders include:

Supraventricular (above the ventricles) tachycardia: Episodes when your heart suddenly beats much faster than normal. It affects the heart’s upper chambers.

Atrial fibrillation (AFib): An irregular, sometimes very fast heartbeat that can lead to blood clots in the heart.

Atrial flutter: The heart’s upper chambers beat too quickly. Like AFib, this can lead to stroke.

Atrial tachycardia: The heart beats too fast due to problems with electrical signals in the heart’s upper chambers.

Ventricular tachycardia: The heart beats too fast due to problems with electrical signals in the heart’s lower chambers. Your heart may not be able to pump enough blood to your lungs and other parts of your body.

Premature ventricular contractions: Extra heartbeats that start in one of the lower chambers.

Complete heart block: Electrical signals that should travel from your heart’s upper chambers to the lower chambers are blocked. This causes a slow or irregular heartbeat and means your heart can’t pump blood to other parts of your body.

Long QT syndrome: Fast, irregular heartbeats that can cause fainting or seizures. Some people are born with this problem.

Brugada syndrome: A rare and sometimes dangerous heart rhythm disorder that can be passed down in families.

Various cardiomyopathies: Any disease that causes the walls of the heart chambers to stretch, thicken, or stiffen can cause heart rhythm problems.

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