How is atrial fibrillation diagnosed?

Some people who have atrial fibrillation (AF) don't have symptoms. For these people, AF often is found during a physical exam or EKG (electrocardiogram) test done for another purpose. Other times, AF is diagnosed after a person goes to the doctor because of symptoms.

To understand why a person has AF and the best way to treat it, the doctor will want to find any immediate or underlying causes of the condition.

Doctors use several methods to diagnose AF, including taking medical and family histories, doing a physical exam, and doing several tests and procedures.

Specialists Involved

A primary care doctor often is involved in the initial diagnosis and treatment of AF. These doctors can include family practitioners and internists.

Doctors who specialize in the diagnosis and treatment of heart disease also may be involved, such as:

• Cardiologists. These are doctors who diagnose and treat heart diseases and conditions.
• Electrophysiologists. These are cardiologists who specialize in arrhythmias.

Physical Exam

Your doctor will do a complete cardiac exam, listening to the rate and rhythm of your heartbeat and taking your pulse and blood pressure reading. He will likely check to see whether you have any signs of heart muscle or valve problems. Your doctor will listen to your lungs to check for signs of heart failure.

Diagnostic Tests and Procedures

Diagnostic tests and procedures such as following are also used for diagnosis:

• EKG
• Holter and Event Monitors
• Stress Test
• Echocardiography
• Transesophageal Echocardiography
• Chest X Ray
• Blood Tests

This answer from the National Heart, Lung and Blood Institute has been reviewed and/or edited by Dr. William D. Knopf.

To assess you for Afib and make a diagnosis, your doctor will do various tests, such as:

    • History, physical exam, and blood tests: your doctor will ask about
      your symptoms and medical history, listen to your heart, and test
      for factors that might be related to your symptoms.

    • Chest x-ray: your doctor may take a chest x-ray to look at your
      heart and lungs.

    • Electrocardiogram (ECG or EKG): this test records the electrical
      activity of your heart. Sticky patches (electrodes) are attached to
      your chest and send signals to a recorder. You might be asked to
      exercise during this test to see how your heart responds to extra
      activity.

    • Echocardiogram (heart ultrasound): this test uses high-frequency
      sound waves to create images of your heart and blood vessels.

    • Stress testing: if your doctor feels it’s needed, you might exercise
      on a treadmill and have an EKG or echocardiogram while your heart
      is working harder. If you can’t exercise, medication will be used to
      temporarily stress your heart.

    • Holter monitor or event recorder: because Afib can come and go,
      an EKG or echocardiogram might not catch the problem. A Holter
      monitor is a small recorder that you wear for 24 to 48 hours while
      you go about your normal activities. It measures the electrical
      activity of your heart and can sometimes catch the problem.

    • EP (electrophysiology) study: in this test, one or more catheters
      (small, flexible tubes) are inserted into a major blood vessel and
      threaded to your heart. Doctors use tiny sensors on the catheters
      to capture and record your heart’s activity, and may be able to
      identify the heart cells that are causing the problem.

To assess you for atrial fibrillation (Afib) and make a diagnosis, your doctor will do various tests, such as:

• History, physical exam and blood tests. Your doctor will ask about your symptoms and medical history, listen to your heart, and test for factors that might be related to your symptoms.
• Chest x-ray. Your doctor may take a chest x-ray to look at your heart and lungs.
• Electrocardiogram (ECG or EKG). This test records the electrical activity of your heart. Sticky patches (electrodes) are attached to your chest and send signals to a recorder. You might be asked to exercise during this test to see how your heart responds to extra activity.
• Echocardiogram (heart ultrasound). This test uses high-frequency sound waves to create images of your heart and blood vessels. Depending on your medical situation, this might use an ultrasound probe that moves over your chest, or a TEE (transesophageal echocardiogram) that uses a tiny ultrasound probe in your esophagus.
• Stress testing. If your doctor feels it's needed, you might exercise on a treadmill and have an EKG or echocardiogram while your heart is working harder. If you can't exercise, medication will be used to temporarily stress your heart.
• Holter monitor or event recorder. Because Afib can come and go, an EKG or echocardiogram might not catch the problem. A Holter monitor is a small recorder that you wear for 24 to 48 hours while you go about your normal activities. It measures the electrical activity of your heart and can sometimes catch the problem. Or, you might wear an event monitor for a longer period -- this small recorder saves a recording of your heart's activity when you feel a symptom.
• EP (electrophysiology) study. In this test, one or more catheters (small, flexible tubes) are inserted into a major blood vessel and threaded to your heart. Doctors use tiny sensors on the catheters to capture and record your heart's activity, and may be able to identify the heart cells that are causing the problem.