A diagnosis of Atrial Fibrillation (AF or AFib) is often made by pulse palpation, in which the pulse is classically described as being ‘irregularly irregular’. A systematic review concluded that pulse rate is 94% sensitive and 72% specific for diagnosis (positive likelihood ratio = 3.4; negative likelihood ratio = 0.08).¹ Confirmation of AF requires a rhythm recording displaying the electrical activity of the heart using an electrocardiogram (ECG or EKG ), showing the typical pattern of AF: completely irregular RR intervals, an absence of P waves, and coarse or fine fibrillation waves at baseline. An episode lasting at least 30 seconds is diagnostic.^2,3 This is traditionally carried out using a standard 12-lead ECG or continuous ambulatory ECG monitoring. ECG changes can be subtle and interpretation should be performed by a competent clinical practitioner to ensure accuracy.

A normal test result however does not completely rule out the presence of AF, as the ECG may not capture paroxysmal arrhythmia. In these cases, a Holter monitor (24-hour recording) or an event monitor (7–30 day recording) may be required to measure the patient’s heart rhythm over a prolonged period of time.¹