Atrial fibrillation is one of the most common heart rhythm disturbances and is considered benign (that is, not life-threatening). However, it's also one of the most frustrating arrhythmias to deal with for both patients and doctors, because there's a broad range of symptoms and medical problems that can result from atrial fibrillation, and a lack of highly effective and safe therapies.
What Is Atrial Fibrillation?
Atrial fibrillation is a rapid and irregular heart arrhythmia, caused by chaotic electrical impulses in the atria of the heart (the two upper chambers). In anatomical terms, the AV node and the ventricles (the two lower chambers) are therefore bombarded with frequent, irregular electrical impulses. As a result, the heart rate becomes fast and irregular, and the normal coordination between the atria and the ventricles is lost. Click here for a description of the normal heart rhythm.Consequences of Atrial Fibrillation
Patients with atrial fibrillation can have a range of symptoms. They are caused by the rapid heart rate, and the loss of coordination between the atria and ventricles. People who have atrial fibrillation often complain of:
- palpitations (an unusual awareness of the heartbeat),
- becoming fatigued easily,
- shortness of breath,
- and (occasionally) lightheadedness.
In fact, if the heart rate associated with atrial fibrillation is rapid enough and persists long enough (that is, for at least several months), some patients well develop cardiomyopathy and heart failure as a direct consequence.
Risk of Stroke
Possibly the biggest problem with atrial fibrillation is that if the arrhythmia lasts for a day or two, the ineffective pumping action of the atria (caused by the chaotic electrical activity) can allow blood clots to form within the atria. If these blood clots break off and get into the bloodstream, a stroke can result.
Thus, patients who are in prolonged or chronic atrial fibrillation have a significantly increased risk of stroke.
Types of AF
There are several types, depending on how long the AF lasts.
- When atrial fibrillation is always present, it is referred to as chronic or permanent atrial fibrillation.
- When the arrhythmia is usually present, such that episodes of normal rhythm are infrequent or short-lived, it is referred to as persistent atrial fibrillation.
- When a normal heart rhythm is usually present but occasional episodes of the arrhythmia occur, the patient is said to have paroxysmal atrial fibrillation.
Atrial Fibrillation -- In Depth
Want to know more about AF? The following links discuss the causes, the diagnosis and the treatment of atrial fibrillation:
The Causes of Atrial Fibrillation
