What it is
Atrial fibrillation is an abnormal heart rhythm. The heart's electrical system normally sends regularly spaced signals. These signals tell the heart muscle to contract or beat. The heart has two upper chambers called atria. It also has two lower chambers called ventricles. Each signal starts in the atria and travels to the rest of the heart. In atrial fibrillation, the electrical signals from the atria are fast and irregular. The atria shake instead of contract. Signals reach the ventricles in an irregular fashion, causing irregular and sometimes rapid beating of the heart. This rhythm can reduce the heart’s ability to pump blood out to the body. Blood left in the heart chambers can form clots. These clots may sometimes break away and travel to the brain, and can cause stroke.

Causes, Risk Factors & Symptoms

In most cases, atrial fibrillation is due to an existing heart condition. Atrial fibrillation can also occur in people who do not have structural heart problems. A thyroid disorder or other condition may cause the abnormal rhythm. The cause of atrial fibrillation is sometimes unknown.

Risk Factors

  • Atrial fibrillation is more common in men and in people aged 55 years and older. Other factors that may increase your chance of atrial fibrillation include:
  • Family history of atrial fibrillation
  • Cardiovascular diseases, such as high blood pressure, coronary artery disease, heart failure, heart attack, heart valve disease, endocarditis, cardiomyopathy, congenital heart disease, prior episode of atrial fibrillation
  • Lung diseases, such as emphysema, asthma, blood clots in the lungs
  • Chronic conditions, such as overactive thyroid, diabetes
  • Prescription medications to treat chronic conditions, such as opioids for pain relief
  • Lifestyle factors: smoking, excessive alcohol use, excessive use of stimulants like caffeine, physical and/or emotional stress, receiving general anesthesia

Symptoms can be mild to severe. This depends on your heart function and overall health. Some people may not notice any symptoms. In those that have them, symptoms may include:

  • Irregular or rapid pulse or heart beat
  • Racing feeling in the chest
  • A pounding feeling in the chest
  • Lightheadedness, which can lead to fainting
  • Sweating
  • Pain or pressure in the chest
  • Shortness of breath
  • Fatigue or weakness
  • Unable to exercise

Diagnosis & Treatment

The doctor will:

  • Ask about your symptoms and medical history
  • Perform a physical exam
  • Listen to your heart with a stethoscope
  • Order blood tests to help diagnose the problem

Imaging tests may include:

  • Chest X-ray
  • Echocardiogram
  • Coronary angiography

Electrical activity tests of your heart can be done with:

  • Electrocardiogram (EKG)
  • Holter monitor

The goals of treatment are to:

  • Return your heart to a regular rhythm.
  • Keep your heart rate close to normal. In general, your resting rate should be between 60-80 beats per minute. It should be 90-115 beats per minute during moderate exercise.
  • Prevent blood clots from forming, reducing the risk of stroke.

Your doctor may find another condition that is causing atrial fibrillation. This condition may be treated. In some cases, heart rhythm problems return to normal without treatment. Treatment options include:

Medical Drug Therapy. Medications may be used to:

  • Slow the heart rate
  • Keep the heart in a regular rhythm
  • Prevent clot formation

Weight Management

Maintaining a healthy weight through diet and exercise may reduce the frequency, duration and severity of atrial fibrillation episodes.

Procedures Performed by St. Elizabeth's Medical Center's Electrophysiology Services:

  • Cardioversion. This procedure uses an electrical current or drugs to help normalize the heart rhythm.
  • Catheter Ablation. An area of the heart that is responsible for atrial fibrillation may be surgically removed or altered.
  • Convergent Approach. At St. Elizabeth's, patients with the most difficult-to-control atrial fibrillation can be treated with an ablation procedure. During this procedure, a cardiac surgeon and electrophysiologist work as a team to perform a cardiac ablation. This is a a minimally invasive approach in which a cardiac surgeon makes a small incision in the patient's abdomen and then performs an ablation across the back wall of the heart. The next day, the electrophysiologist threads an ablation catheter through the patient's femoral vein in the groin to reach the inside of the heart to complete the ablation and ensure they are connected. Electrophysiology diagnostics are then used to confirm the abnormal electrical signals were interrupted. At St. Elizabeth’s, most patients treated with the Convergent Approach are able to go home within two to three days, resume a more active lifestyle, and may be able to stop taking medication to treat atrial fibrillation.
  • Watchman FLX™ Left Atrial Appendage Closure (LAAC) Implant. For appropriate patients with non-valvular atrial fibrillation (AF) St. Elizabeth’s offers the Watchman FLX™ Left Atrial Appendage Closure (LAAC) Implant, an alternative to long-term warfarin medication that is designed to help reduce the risk of stroke in patients with AF. For patients with atrial fibrillation who are considered suitable for warfarin by their physicians but who have reason to seek a non-drug alternative, the Watchman FLX™ LAAC is an implant alternative to reduce their risk of AF-related stroke. Roughly the size of a quarter, the Watchman device closes off an area of the heart called the left atrial appendage (LAA) to keep harmful blood clots from the LAA from entering the bloodstream and potentially causing a stroke. By closing off the LAA, the risk of stroke may be reduced, and, over time, patients may be able to stop taking warfarin. Implanting the Watchman Device is a one-time procedure that usually lasts about an hour. Following the procedure, patients typically need to stay in the hospital for 24 hours.
  • Direct Left Bundle Pacing. Ineffective contraction of the heart, also known as desynchrony, in the lower right chamber may result over time from a standard pacemaker procedure or electrical cardiac disease. The direct left bundle procedure is an evolution of His-bundle pacing and decreases the risk of desynchrony. The direct left bundle procedure uses a thinner lead, which is placed centimeters deeper in the septum. This placement uses natural pathways of the heart’s conduction system whereas a standard pacemaker procedure placement uses less.


To help reduce your chance of atrial fibrillation:

  • Avoid known triggers
  • Exercise regularly within your doctor's guidelines
  • Control other chronic conditions, such as heart disease or diabetes