Tests and diagnosis

By Mayo Clinic Staff

To diagnose atrial fibrillation, your doctor may do tests that involve the following:

  • Electrocardiogram (ECG). In this noninvasive test, patches with wires (electrodes) are attached to your skin to measure electrical impulses given off by your heart. Impulses are recorded as waves displayed on a monitor or printed.
  • Holter monitor. This is a portable machine that records all of your heartbeats. You wear the monitor under your clothing. It records information about the electrical activity of your heart as you go about your normal activities for a day or two. You can press a button if you feel symptoms, so your doctor can know what heart rhythm was present at that moment.
  • Event recorder. This device is similar to a Holter monitor except that not all of your heartbeats are recorded. There are two recorder types: One uses a phone to transmit signals from the recorder while you're experiencing symptoms. The other type is worn all the time (except while showering) for as long as a month. Event recorders are especially useful in diagnosing rhythm disturbances that occur at unpredictable times.
  • Echocardiogram. In this noninvasive test, sound waves are used to produce a video image of your heart. Sound waves are directed at your heart from a wand-like device (transducer) that's held on your chest. The sound waves that bounce off your heart are reflected through your chest wall and processed electronically to provide video images of your heart in motion, to detect underlying structural heart disease.
  • Blood tests. These help your doctor rule out thyroid problems or other substances in your blood that may lead to atrial fibrillation.
  • Chest X-ray. X-ray images help your doctor see the condition of your lungs and heart. Your doctor can also use an X-ray to diagnose conditions other than atrial fibrillation that may explain your signs and symptoms.
Feb. 08, 2013