Patients & Family
Arrhythmias
- Arrhythmias
- Atrial fibrillation
- Other types of arrhythmia
Atrial fibrillation
What is AFib?
Atrial fibrillation (also known as AFib) is the most common arrhythmia disorder in adults. The likelihood of developing AFib increases with age, and it is estimated to affect 1 in 25 adults 60 years or older and nearly 1 in 10 adults 80 years or older (Go et al. 2001). AFib causes the upper chambers of the heart (the atria) to beat in an uncoordinated manner. The uncoordinated beating causes an irregular pulse and sometimes a feeling of fluttering or palpitations in the chest.
Causes of AFib
During AFib, the normal regular electrical impulses that the sinus node sends to the heart chambers are replaced by disorganised, rapid electrical signals that occur spontaneously, without a signal from the sinus node.
When this happens often enough, it causes the atria to contract irregularly and they may begin to fibrillate, leading to the sensation of fluttering or palpitations.
Figure. Changes in normal conduction of electrical pathways (from patient leaflet)
Symptoms of AFib
Sometimes, AFib does not cause any symptoms at all. This is called asymptomatic AFib. In other patients, or at certain times in the same patient, AFib may cause symptoms such as (Fuster V. et al. 2006):
- Palpitations
- Fainting
- Chest pain
- Weariness/fatigue
- Unaccountable sweating
- Shortness of breath
Problems and risks associated with having AFib
During an episode of AFib, the atria do not contract fully, meaning that some of the blood that should have been pumped to the ventricles remains in the atria.
It is possible that the blood that remains in the atria may pool and clot together. If the clot breaks free from the heart and travels in the bloodstream, the risk of having a stroke is increased.
Different patterns of AFib
There are several different patterns used to describe AFib (Fuster V, et al. 2006). A patient who has experienced two or more identified episodes of AFib is said to have recurrent AFib.
Recurrent AFib can be further classified into paroxysmal AFib, persistent AFib or permanent AFib, based on whether and when the episode terminates without treatment(Fuster V, et al. 2006).
- Paroxysmal AFib is a type of AFib that occurs every now and then and varies in duration from a few seconds to longer protracted episodes that last several hours or even days. This type of AFib will stop on its own without treatment, usually within 24 hours.
- Persistent AFib is a type of AFib that lasts for more than 7 days and has to be stopped by a procedure called cardioversion, which can return the heart back to a normal rhythm. Cardioversion attempts to reset the heart either using drugs or by delivering an electric shock to the heart.
- Permanent AFib is a type of AFib that occurs continuously. The AFib never stops and becomes the only type of rhythm that the heart is able to produce. This type of AFib is usually unresponsive to therapy and is typically seen in older people.
It is quite common for patients to present to their doctor with paroxysmal AFib, which then lasts longer and longer, until eventually the AFib becomes persistent or permanent. This is because AFib itself causes more AFib. This happens because AFib causes changes in the electrical properties of the atria, making them more likely to cause or sustain more AFib.
