Atrial fibrillation

Dr Henry Knipe and Dr David Carroll et al.

A common consequence of atrial enlargement and/or inflammation, atrial fibrillation is a dysrhythmia originating from the atria, typically recognized on the electrocardiogram. It most commonly presents as a tachydysrhythmia, with ventricular rates between 120-130 beats per minute. Defining electrocardiographic features include; an absence of defined P wave, irregularly irregular R-R intervals, and narrow QRS complexes (in the absence of other conduction system pathology).

Cardiac imaging plays an important role in the identification of the cause, assessment for intervention, and potential thromboembolic complications.


Atrial fibrillation is present in ~5% of patients over 65 years old. The presence of new-onset atrial fibrillation may provide diagnostic assistance due to its well-identified associations, which include 2;

Clinical presentation

Presentation varies based on the underlying cause, but commonly includes;

  • palpitations
  • shortness of breath
  • fatigue
  • altered mentation

Article information

rID: 66191
System: Cardiac
Tag: cases
Synonyms or Alternate Spellings:
  • A Fib
  • AF

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