How Doctors Diagnose Atrial Fibrillation

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Women patient in doctors office

Atrial fibrillation is the most common type of irregular heartbeat. People often simply call it afib. Your doctor may suspect this condition if you have certain telltale symptoms, if you're older, and if you have health problems like high blood pressure or a history of heart disease. However, it's possible to have afib without having the usual symptoms. Or, like many with afib, you might have no symptoms. 

So how do doctors reach an afib diagnose? They do it by asking about your symptoms, medical history, and family history. After a thorough physical exam, your doctor may order tests, such as an atrial fibrillation ECG, that can confirm the diagnosis. 

Your primary care doctor may be the one to diagnose afib. Or, your doctor may have you see a cardiologist—a heart specialist. You might also see an electrophysiologist. That's a cardiologist with special training in abnormal heart rhythms. 

If Your Doctor Suspects an Afib Diagnosis

Your doctor will likely start by asking if you have any of these afib symptoms: 

  • Feeling weak, dizzy or tired
  • Racing heartbeat
  • Skipped heartbeats
  • Sweating with chest pain

Because afib may run in families, your doctor will ask if anyone in your family has had afib or other types of heart disease. The doctor may also ask about high blood pressure, previous heart problems, lung disease, smoking, drinking, and thyroid problems. These are all possible causes of afib. 

During your physical exam, the doctor will feel your pulse, take your blood pressure, and listen to your heart and lungs. The doctor will also check your ankles for swelling, a sign of heart failure. Because an overactive thyroid can cause afib, your doctor will examine your thyroid gland, which is in the front of your neck. 

Tests for Atrial Fibrillation

Of possible afib tests, the most informative is an ECG (electrocardiogram). Your doctor will put electrodes on your chest to record your heart rate and rhythm. If you're having an afib episode, your doctor will see it and can make the diagnosis. 

If you don't have an afib episode during the ECG, you may need one or more of these other tests: 

  • Holter monitor. This is a type of ECG that you wear for a day or two. You keep the electrodes on your chest, wear the recorder, and go about your daily routine. Your doctor will look at the results from the recorder when you’re finished with the test.
  • Event monitor. You might wear this monitor for a month. It doesn’t operate continuously. It will turn on if it senses a change in your heartbeat. You can also switch it on if you feel symptoms.
  • Stress test. This is a type of ECG done while you're exercising on a treadmill. This test is done because exercise sometimes triggers afib.
  • Echocardiogram. This test uses sound waves to take a moving picture of your heart. A technician will move a device that looks like a wand (a transducer) across your chest. You’ll feel the wand on your skin, but it isn’t painful. 
  • Transesophageal echocardiogram (TEE). Afib starts in the upper chambers of your heart. To get a look at that area, a sound wave transducer is placed in your esophagus so it's close to your heart. This test can be a little uncomfortable, so you will be given some medicine to help you relax.

If you, your primary care doctor, or another caregiver suspects you may have afib, use this article to guide your diagnosis. When you’re with your doctor, it can be difficult to remember all your symptoms and your medical history. Keep a small notebook of your symptoms and history and bring it with you to your appointments. This will help your doctor understand the situation and take the appropriate steps to reach a diagnosis. With the right diagnosis, you can move on to treatment.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Aug 2
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.

  1. Atrial Fibrillation (Afib). Cleveland Clinic.

  2. How Is Atrial Fibrillation Diagnosed? National Institutes of Health. National Heart, Lung, and Blood Institute.

  3. How to Know It’s Atrial Fibrillation.