Resources > Heart Conditions > Atrial Fibrillation (AFib)

Atrial Fibrillation (AFib)

Atrial fibrillation is a type of abnormal heart rhythm (arrhythmia) of your heart. It is the most common type of arrhythmia, affecting approximately 350,000 Canadians. Individuals with atrial fibrillation have a 3 to 5-time greater risk of stroke than those without it.

Atrial fibrillation happens when electrical impulses fire from different places in the atria (the top chambers of the heart) in a disorganised way. This causes the atria to twitch, and is felt as an irregular heartbeat or pulse.

Causes Often, the cause of atrial fibrillation is not known. Causes may include:

  • high blood pressure
  • heart valve disease
  • abnormal structure of the heart
  • excessive alcohol consumption

Symptoms Some people with atrial fibrillation may feel perfectly fine. They may not even know they have the condition until they have an electrocardiogram. Others may experience various symptoms including:

  • irregular and fast heartbeat
  • heart palpitations or a rapid thumping in their chest
  • chest discomfort, chest pain or pressure
  • shortness of breath, particularly with exertion or anxiety
  • fatigue
  • dizziness, sweating or nausea
  • light-headedness or fainting

Diagnosis If your doctor suspects you have atrial fibrillation, they may suggest tests including an electrocardiogram (ECG) or echocardiogram.

TreatmentSome people with atrial fibrillation require medications to help control the speed and rhythm of their heart. These are commonly beta-blockers and anti-arrhythmic drugs. Occasionally, a procedure such as ablation or cardioversion is required. Your doctor will customize your treatment based on your risks and medical profile, as well as how much your symptoms interfere with your quality of life.

Many people with atrial fibrillation have to take blood thinners to reduce their risk of stroke. This risk depends on several factors, including the presence of heart muscle weakness, high blood pressure or diabetes, being over 75, and having had a previous stroke or a mini-stroke.