Atrial fibrillation is a heart condition that causes an irregular and often abnormally fast heart rate but is usually not life threatening. Atrial fibrillation is the most common heart rhythm disturbance, known to be more prevalent in over 65s, those with high blood pressure, and smokers. Symptoms of atrial fibrillation may present as heart palpitations, where the heart feels like it is fluttering or beating irregularly, for several seconds or minutes. Sometimes atrial fibrillation does not cause any symptoms and a person who has it is completely unaware that their heart rate is irregular.
There are 4 categories of atrial fibrillation that differ in severity and how much they can impact on the individual:
- Paroxysmal atrial fibrillation– episodes come and go, and usually stop within 48 hours without any treatment
- Persistent atrial fibrillation– each episode lasts for longer than 7 days (or less when it’s treated)
- Long-standing persistent atrial fibrillation– continuous atrial fibrillation for a year or longer
- Permanent atrial fibrillation– where atrial fibrillation is present all the time
The cause of atrial fibrillation is not fully understood but changes from regular heartbeat contractions occur in the atria. During a regular heartbeat, the atrial muscular walls contract to force blood into the ventricles and then out and around the body. Relaxation then occurs to allow the atria to fill with blood again. During atrial fibrillation the atria contract randomly, which can be due to abnormal electrical impulses spontaneously firing in the atria. This can result in contraction which is sometimes too fast to relax properly between beats and fully empty of the blood they fill with. The spontaneous impulses in the atria can override the heart’s natural pacemaker, which can no longer control the rhythm of the heart. This causes a highly irregular pulse rate.
To access up to date information on symptoms and management click on the links below:
NICE Guidelines: Atrial Fibrillation
NHS Conditions: Atrial Fibrillation