Evaluating and Diagnosing Atrial Fibrillation

ECG output
Science Photo Library / Getty Images

In contrast to the diagnostic puzzle posed by many medical conditions, there is little mystery to diagnosing atrial fibrillation. Making a firm diagnosis is simply a matter of seeing the arrhythmia on an electrocardiogram (ECG).

Tests for Diagnosing A-Fib

If you are having atrial fibrillation when you first seek medical help, the diagnosis will become immediately apparent as soon as an ECG is performed.

On the other hand, you might have paroxysmal (intermittent) atrial fibrillation, with symptoms that come and go, and the ECG in the doctor’s office may be normal. Here, ambulatory monitoring (wearing an ECG recorder for a few days or a few weeks) will eventually reveal the problem. The trick is to make sure ambulatory monitoring continues until at least one episode of symptoms is captured.

It is even possible for you to have no discernible symptoms whatsoever, and the arrhythmia may be detected as an unexpected “incidental finding,” on an office ECG, or during a stress test or an ambulatory monitoring study that is being done for other reasons.

But one way or another, diagnosing atrial fibrillation is a matter of capturing the arrhythmia on an ECG.

Evaluating Atrial Fibrillation

Once atrial fibrillation has been diagnosed, the real work begins.

As a next step, your doctor will perform a full medical evaluation to characterize your arrhythmia and its potential causes as fully as possible.

You will need to be thorough in telling your doctor about your medical history. Be sure to tell him/her about any symptoms you have had that could be related to atrial fibrillation—palpitations, easy fatiguability, shortness of breath, chest discomfort, or episodes of lightheadedness or passing out. Try to recall any events or behaviors that seem to bring on your symptoms—such as exercise, emotional upset, sleeping poorly, or drinking alcohol.

Your doctor will ask you about any symptoms that might suggest underlying cardiovascular or lung disease, and will perform a careful physical examination looking for any additional clues (for instance, the presence of hypertension). Your doctor should take special care to check for reversible causes of atrial fibrillation, since treating these conditions is likely to keep the arrhythmia from recurring. Reversible causes include hyperthyroidism, pulmonary embolus, pericarditis, and recent surgical procedures.

And don’t be upset if your doctor asks you more than once about alcohol. Atrial fibrillation can be triggered by alcohol ingestion—in some people, even small amounts of alcohol can do it. Because alcohol is one of the few truly reversible causes of atrial fibrillation, it is important for your doctor to assess this aspect of your history carefully.

Other Testing

Blood testing: In addition to standard blood testing (including a fasting blood sugar to look for signs of diabetes), it is important for your doctor to get thyroid function tests. Especially in older people, thyroid problems can be present without any of the classic symptoms.

ECG: In addition to providing the diagnosis of atrial fibrillation, the ECG can give important clues about the presence or absence of underlying heart disease.

Echocardiogram: An echocardiogram should be done to evaluate the cardiac valves and chambers, looking again for signs of underlying heart disease. It may also be necessary to do a transesophageal echocardiogram (a TEE), in which the echo transducer is passed into the esophagus (swallowing tube) directly behind the heart. The TEE can be useful in looking for blood clots in the left atrium before performing a cardioversion. (We will talk about cardioversion later.)

Stress test: A stress test is usually not necessary for the evaluation of atrial fibrillation, but may be helpful if your medical history or your symptoms suggest the presence of coronary artery disease.

Once all this information is gathered, it is time for you and your doctor to begin discussing treatments for atrial fibrillation.

Was this page helpful?
Article Sources
  • January CT, Wann LS, Alpert JS, et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines and the Heart Rhythm Society. Circulation 2014; 130:e199.