10 Things to Know About Atrial Fibrillation (AFib)

Symptoms, causes, treatments and who’s at risk

An EKG of AFib.

Symptoms, causes, treatments and who’s at risk

A fast-beating heart can be concerning, but it’s not always a serious issue. Stress or anxiety can cause it. Excessive caffeine or alcohol can do it too. Issues can occur if it’s caused by a condition known as atrial fibrillation or AFib.


AFib is a heart condition that affects millions of people in the United States. It is an abnormal rhythm of the upper chambers of the heart that can have severe consequences if not under control.


“AFib is a serious heart condition that increases the risk of stroke. It can occur with or without symptoms,” says Douglas Gibson, MD, a cardiologist and director of cardiac electrophysiology at Scripps Clinic. “The good news is that AFib is a manageable condition with the help of a good medical team.”


If you have AFib, your doctor may refer you to an electrophysiologist who specializes in the heart's electrical signaling.


Here are common questions about AFib, including symptoms, causes, treatments, and risk factors. The information can help you better understand this manageable heart condition.

1.   Why is AFib such a high-risk concern?

With AFib, the heart stops pumping blood effectively and this causes two problems.

First, it may cause symptoms, such as lightheadedness, dizziness and shortness of breath. Second, AFib can significantly increase the risk of stroke.


The condition disrupts the normal rhythm of the heart, causing the upper chambers (atria) to quiver instead of contracting efficiently.


“When the upper chambers quit pumping blood effectively, blood can pool in those chambers, causing blood clots to form. Those blood clots can then leave the heart and travel to the brain, causing stroke,” Dr. Gibson says.


AFib is the most common type of heart arrhythmia, where the heart beats too slowly, too fast or in an irregular way. AFib causes one in seven strokes in the United States, according to the Centers for Disease Control and Prevention (CDC).

AFib causes more than 450,000 hospitalizations and 158,000 deaths each year in the U.S. AFib-related deaths have been rising for more than two decades, according to the CDC.


The number of people with AFib continues to increase as the population ages. It is estimated that 12 million people in the U.S. will have AFib by 2030, according to the CDC.

2.   What causes AFib?

AFib is the result of abnormal or damaged heart muscle that can lead to rapid electrical firing and an irregular heartbeat. Conditions that damage heart muscle and are often associated with AFib include:


  • High blood pressure
  • Heart attack
  • Coronary artery disease
  • Abnormal heart valves
  • Heart defects
  • An overactive thyroid gland
  • Exposure to stimulants, such as medications, caffeine, tobacco or alcohol
  • Sick sinus syndrome — improper functioning of the heart's natural pacemaker
  • Lung diseases
  • Previous heart surgery
  • Viral infections
  • Sleep apnea
  • High level athletic activity such marathon running, long distance biking or swimming


Sometimes the cause of AFib is unknown.

3.  Can a racing heart be a medical condition other than AFib?

Yes. There are many heart rhythm disorders that can cause a faster than normal heartbeat. These include atrial flutter, supraventricular tachycardia (SVT), or ventricular tachycardia (VT).

4.  Can AFib lead to heart failure?

AFib can cause heart failure by reducing the heart’s ability to pump blood efficiently to meet the body’s requirements. Heart failure is a severe condition.


“If the heart beats too fast for too long, that can cause the lower pumping chambers to fail and that can cause fluid to retain in the lungs and swelling in the legs. These are symptoms that we would typically associate with heart failure,” Dr. Gibson says. “Atrial fibrillation can worsen heart failure as well.”

5.  How is AFib diagnosed?

AFib is typically diagnosed through an electrocardiogram (ECG or EKG). This test involves placing electrodes on the chest to monitor the heart’s electrical activity. The purpose is to identify any abnormalities in the heart’s rhythm.


An EKG can be done at the doctor’s office. Patients may also need to wear a heart monitor at home to track their heart rhythm.

6.  Are women with AFib at higher for severe strokes?

In some studies, women are at higher risk of stroke when compared to men with AFib. “This increase in risk appears to be mild but significant when other risk factors for stroke are present in a female patient,” Dr. Gibson says.

7. How are risk factors assessed?

CHA2DS2-VASc score is a medical tool used to asses the risk of stroke in patients with AFib and help guide treatment to prevent stroke.

The acronym stands for the individual risk factors it assesses:

  • Congestive heart failure
  • Hypertension
  • Age
  • Diabetes
  • Sex
  • Stroke or transient ischemic attack
  • Vascular disease

Each risk factor is assigned a score, and the total score indicates the level of stroke risk. Higher scores indicate a higher risk of stroke, prompting the need for more aggressive prevention strategies.

“When a person has a score of 2 or greater, stroke prevention strategies need to be carefully considered,” Dr. Gibson explains.

8.   What are the best treatment options for AFib?

When choosing the best treatment for AFib, doctors consider the symptoms’ severity, stroke risk factors, and other related conditions.


Treatment goals generally include symptom management and stroke prevention. Managing risk factors is an important part of AFib treatment. “Issues, such as sleep apnea and blood pressure control, need to be addressed,” Dr. Gibson says.


Treatment options include medications to control heart rate and rhythm, blood thinners to reduce the risk of clots and strokes and lifestyle changes, such as weight loss and exercise. Procedures may be considered for carefully selected individuals.

9.   What is the Watchman device?

The Watchman device is a medical implant used to reduce the risk of stroke in people with AFib. It is inserted into the left atrial appendage (a small pouch in the left atrium) to prevent blood clots from forming and traveling to the brain. This device can be an alternative for those who cannot tolerate blood thinners.

10. What is catheter ablation?

Catheter ablation is a minimally invasive procedure that targets the abnormal heart tissue responsible for the irregular electrical symptoms. This helps restore a normal heart rhythm.


When AFib is treated with ablation, it’s called atrial fibrillation ablation. “This procedure may be part of a comprehensive treatment plan and is done only after carefully considering a patient’s situation,” Dr. Gibson says.


Scripps was the first San Diego health system to use catheter ablation to treat arrhythmias.

Scripps is home to a team of medical professionals who are experts in diagnosing and treating abnormal heart rhythms, such as AFib, and in researching ways to treat cardiac arrhythmia.

Scripps is nationally recognized as a heart care leader and consistently ranked by U.S. News & World Report as one of America’s Best Hospitals for cardiology and heart surgery.

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