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The electrocardiogram in atrial fibrillation

Brian Olshansky, MD
Section Editors
Ary L Goldberger, MD
Bradley P Knight, MD, FACC
Deputy Editor
Gordon M Saperia, MD, FACC


Atrial fibrillation (AF) can cause significant symptoms and impair functional status and quality of life, and can increase the risk of stroke and death. (See "Overview of atrial fibrillation".)

The diagnosis of AF is often based on a 12 lead electrocardiogram (ECG) characterized by absence of discrete P waves and an irregularly irregular ventricular rate. In most patients, a single ECG is sufficient to secure the diagnosis, assuming the patient is in AF at the time of the ECG. In some patients it is also diagnosed using a heart rhythm recording such as a telemetry strip, Holter monitor, or an event monitor.

Occasionally, the electrocardiographic diagnosis of AF may be difficult. (See 'Difficulties in diagnosis' below.) Further, other rhythm disturbances may be confused with AF.

This topic will review the electrocardiographic features of AF. The mechanisms of AF are presented separately. (See "Mechanisms of atrial fibrillation".)


AF is associated with the following changes on ECG (waveform 1 and waveform 2 and waveform 3):


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Literature review current through: Sep 2016. | This topic last updated: May 1, 2015.
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