What is Atrial Fibrillation?

Normal ECG with regular heart beats

ECG showing atrial fibrillation with irregular heart beats

Atrial Fibrillation is one of the most common types of arrhythmia of the heart.  It is characterised by rapid, irregular contraction of the top chambers of the heart (atria), resulting in an irregular heart beat (bottom left image) that can sometimes cause unpleasant symptoms.  
Atrial fibrillation requires specific treatment to restore the heart's normal beating pattern and prevent possible complications.
Atrial fibrillation can be diagnosed easily on a standard Electrocardiogram (ECG) which reveals the irregular electrical activity of the heart. Sometimes atrial fibrillation can be intermittently present (Paroxysmal) and a longer period of heart monitoring is required to demonstrate the irregularity. In this case a 24 or 48 hour Holter monitor is very helpful to find the problem.