Atrial fibrillation (AF) is an abnormal heart rhythm originating in the top two chambers of your heart (the atria). During atrial fibrillation, the atria beat out of sync with the lower two chambers of the heart (the ventricles). AF is the most common type of arrhythmia, or irregular heart rhythm.

Atrial Fibrillation Symptoms and Diagnosis

Sometimes people with atrial fibrillation experience no symptoms and are unaware of the condition. However, those with symptoms may experience:

  • Palpitations, or feelings of a rapid, uncomfortable, irregular heartbeat or a flopping in your chest
  • Low blood pressure
  • Weakness
  • Shortness of breath
  • Chest pain
  • Lightheadedness
  • Confusion
  • Fatigue

If you have symptoms, see your doctor. If you have had symptoms and experience chest pain, call 911 immediately. This could indicate you are having a heart attack.

Types of Atrial Fibrillation

Paroxysmal atrial fibrillation is when AF comes and goes, lasting for a few seconds to a few days before returning to a normal heart rhythm.

Persistent atrial fibrillation lasts for at least a week and doesn’t stop without treatment to restore a normal rhythm.

Chronic atrial fibrillation occurs constantly and doesn’t stop, even with treatment.

About 30 percent of those with AF have no risk factors. Factors that increase your chances of developing atrial fibrillation include:

  • Age
    • Risk increases as you get older.
    • AF occurs in about 15 percent of those over the age of 75, but it can be seen in younger people as well.
  • Heart disease, including history of valve disease, coronary artery disease, heart attack or heart surgery
  • High blood pressure, particularly if it is not well controlled
  • Excessive alcohol consumption, particularly binge drinking
  • Family history
  • Sleep apnea
  • Thyroid problems
  • Pericardial inflammation

To diagnose AF, your doctor will ask about the severity of your symptoms, your medical and family history. Your doctor also will perform a complete cardiac exam:

  • Listening to the rate and rhythm of your heartbeat
  • Checking your pulse and blood pressure
  • Checking for signs of a problem with your heart muscle or valves
  • Listening to your lungs for signs of heart failure
  • Checking for swelling in the legs or feet
  • Checking for an enlarged thyroid gland or other signs of hyperthyroidism

To help definitively diagnose AF, tests that may be ordered include:

  • Electrocardiogram (ECG)
  • Holter or event monitor, to record your heartbeat
  • Echocardiogram
  • Blood tests, to check thyroid hormones

Atrial Fibrillation Treatment at BIDMC

AF is treatable and typically not life-threatening. If left untreated, it can lead to emergency situations such as stroke and heart failure.

While the heart is in atrial fibrillation, it may not be able to pump effectively, potentially leading to a reduction in the heart's overall ability to pump blood to the rest of the body. Small blood clots can also form in the atria due to the irregular pumping rhythm, increasing the risk of stroke or a larger blood clot in another part of the body.

The main goal of AF treatment is to lessen the risk of stroke and to reduce symptoms caused by a rapid, irregular heartbeat. Your treatment will depend on:

  • How long you've had AF
  • Severity of your symptoms
  • Underlying cause of your problem
  • If you have other heart problems

General treatment options include medication, medical procedures and lifestyle changes.

Treatment of atrial fibrillation also involves resetting or restoring the heart's normal sinus rhythm, called cardioversion.

  • Cardioversion can be accomplished with medications (antiarrhythmics), or by an electrical shock to your heart.
  • Medications, given intravenously or orally, are successful in about 30 to 60 percent of cases, though AF often returns.
  • Electrical shock is successful in about 85 to 95 percent of cases.

More recently, doctors have discovered that the abnormal electrical impulses seen in atrial fibrillation often start in the pulmonary (lung) veins, which drain blood from the lungs into the left atrium of the heart. The abnormal electrical impulses from these veins travel to the left atrium and then to the right atrium, causing atrial fibrillation.

Procedures designed to prevent these electrical impulses from traveling from the pulmonary veins into the left atrium include:

  • Pulmonary vein isolation, or radiofrequency catheter ablation
  • Maze surgical procedures
    • MiniMaze is a minimally invasive surgery
    • Standard or Conventional Maze is a full open-heart surgery

Learn More

If you have AF, the CVI’s expert cardiologists offer many treatment options and care to help you reduce your risk of more serious cardiac conditions.

Arrhythmia Services