What are the causes of atrial fibrillation?
In about 1 in 10 cases of atrial fibrillation (AF) there is no apparent cause. The heart is otherwise fine and there are no other diseases to account for it. This is called lone AF.
There are many conditions that may cause AF, including the following:
- High blood pressure is the most common cause. High blood pressure puts a strain on the heart muscle.
- AF is a common complication of various heart conditions. For example:
- AF is a complication of coronary heart disease. Coronary heart disease is the condition that causes chest pains (angina) and heart attacks and is common in older people.
- Various other heart problems may also trigger AF to develop. For example, AF occurs in some people with heart valve problems, pericardial disease, dilated cardiomyopathy and hypertrophic cardiomyopathy.
- Other conditions and situations that may trigger AF to develop include:
What are the different types of atrial fibrillation?
In AF, the normal controlling timer in the heart is overridden by many random electrical impulses that fire off from the heart muscle in the atria. The atria then fibrillate. This means that the atria only partially squeeze (contract) - but very rapidly (up to 400 times per minute).
Only some of these impulses pass through to the ventricles and they do so in a very random and haphazard way. Therefore, the ventricles contract anywhere between 50 and 180 times a minute but usually between 140 and 180 times a minute. The ventricles contract not only in an irregular way but also with varying force.
Types of atrial fibrillation
There are three different types of AF:
- Paroxysmal AF means that you have episodes of AF that come and go.
- Each episode comes on suddenly but will also stop suddenly without treatment within seven days (usually within two days). The heartbeat then goes back to a normal rate and rhythm.
- The period of time between each episode (each paroxysm) can vary greatly from case to case.
- Although paroxysmal AF means that it will stop on its own, some people with paroxysmal AF take treatment to stop it as quickly as possible after it starts.
- Persistent AF lasts longer than seven days and is unlikely to revert back to normal without treatment. However, the heartbeat can be reverted back to a normal rhythm with treatment.
- Persistent AF tends to come and go so it may come back again at some point after successful treatment.
- Permanent AF is long-term and the heartbeat does not return back to a normal rhythm.
- This may be because treatment has been tried and was not successful, or because treatment has not been tried.
- People with permanent AF are treated to bring their heart rate back down to normal but the rhythm remains irregular.
Did you find this information useful?
- Management of atrial fibrillation; NICE Clinical Guideline (June 2014)
- 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS; European Society of Cardiology (2016)
- Atrial Fibrillation; NICE CKS, October 2015 (UK access only)
- WatchBP Home A for opportunistically detecting atrial fibrillation during diagnosis and monitoring of hypertension; NICE Medical Technologies Guidance, January 2013
- Thoracoscopic exclusion of the left atrial appendage in atrial fibrillation (with or without other cardiac surgery) for the prevention of thromboembolism, NICE Interventional Procedure Guideline (June 2011)
- Isaew A, Adderley NJ, Ryan R, et al; The treatment of paroxysmal atrial fibrillation in UK primary care. Heart. 2017 Jun 1. pii: heartjnl-2016-310927. doi: 10.1136/heartjnl-2016-310927.
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