What tests diagnose atrial fibrillation?

Atrial fibrillation screening is not a full EKG. It is also known as an EKG with electrodes, which means we will apply electrodes to your wrists and ankles. A full EKG is not required to screen for atrial fibrillation.

You may be given an ECG (electrocardiogram), which will measure your heart's electrical signals and transfer them to paper or computer screen for viewing. You might be asked to wear a device that monitors heart activity. Blood tests and X-rays can help diagnose other conditions you might have that could predispose you to chronic atrial fibrillation.

Several tests can diagnose atrial fibrillation by recording the heart’s rhythm so it can be analyzed. These include an electrocardiogram (ECG or EKG), a Holter monitor, a portable-event monitor, and a transtelephonic monitor.

Dr. Mohammad E. Mortada, MD
Cardiologist (Heart Specialist)

The tools doctors use to diagnose atrial fibrillation (AF) include:

12-lead electrocardiogram: An electrocardiogram, also called an ECG, is an easy and reliable method to diagnose AF. Ten sticky electrodes placed on the skin detect the electrical heartbeat. A computer records 12 standardized electrical views of the heart and prints a 12-second sample. Since the ECG takes only a few seconds, it is possible that the results will appear normal if AF is not present at that moment. Even if the ECG runs the entire time you are in the office, there is a low chance of seeing AF that comes and goes.

Holter monitor: If a patient has AF every day, a continuous 24-hour Holter monitor can record it. Holter monitors can show how an episode begins, which is helpful in deciding treatment options. Several adhesive electrodes are stuck on the chest and side, and are attached to a pager-sized recorder carried on a belt or in a pocket.

Event monitor: These portable monitors may be useful if AF symptoms occur less than daily.

  • Patient-activated monitor: If an episode of AF lasts more than 30
            seconds, the patient can use a simple pager-sized monitor,
            placing it on the skin of the chest when symptoms occur.
  • Looping or continuous monitoring recorder: If an episode lasts less
            than 30 seconds or the patient is unsure of when AF is
            occurring, a monitor with patches is worn and a button
            pressed when symptoms occur. Each monitor can send the
            recording over telephone lines to a receiving station where
            they are printed out.

Electrophysiology studies: This test is rarely needed to diagnose AF. An electrophysiology (EP) study is recommended to test for other conditions or irregular heartbeats that may also be present or be causing AF. For example, in some young patients, an abnormal fast rhythm degenerates into AF and it may be important to diagnose this arrhythmia further with an EP study. On the other hand, persons with heart conditions can have irregularities in the lower chambers (ventricles) that may need study to plan for pacemakers or implantable cardioverter defibrillators.

An electrocardiogram (EKG) is used to diagnose atrial fibrillation. It shows the heart’s electrical activity and rhythm. If a patient’s heart goes in and out of atrial fibrillation, a home holter monitor may be used to act as a portable EKG. Initially, the doctor may notice an irregular heartbeat on physical examination. She or he will then order an EKG, which will distinguish atrial fibrillation from other irregular heart rhythms.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.