Atrial Fibrillation Symptoms, Signs and Risks

1. Palpitation – a feeling that ones heart is racing or going faster than normal
   
   
2. Lethargy because the “turbo-charger” of the heart is not working
   
   
3. Shortness of breath
   
   
4. Dizzy spells or fainting– because the heart can go too fast or too slow, preventing it from pumping blood efficiently and thus dropping the blood pressure
   
   
5. Chest pain
   
   
6. Symptoms of stroke – transient or permanent weakness of an area limited to one side of the body

What are the signs of AF?

You may notice that your heart is continuously irregular or unexpectedly fast. The heart rate rises naturally when you exercise but should not be faster than 90 beats per minute if you have been resting for a while. Many patients may not realise they have AF until someone takes their pulse, for example at a routine medical examination.

What are the risks of AF?

Traditionally AF has been considered a benign heart rhythm, i.e. it is not dangerous. Unfortunately this is a belief still held by some doctors who have not kept up to date with research. AF has the following dangers associated with it:

1. Stroke - AF is the commonest cardiac cause of stroke for reasons explained on What is AF page . Certain people are at high risk of stroke. This risk can be reduced by warfarin in high risk patients and aspirin in low risk patients. Many doctors under-prescribe warfarin because they feel that the elderly who are most at risk of stroke, may be at risk of falling and the bleeding because of the warfarin. Many patients refuse to take warfarin because they are concerned about the inconvenience of the regular blood tests and do not understand the risk of stroke and the devastation it can cause. There are newer drugs under trial at the moment that avoid the need for regular blood tests but there are currently problems with these because of potentially serious side effects. It will therefore be some time until they are fully tested and available.
   
   
2. Heart failure – AF can cause heart failure by making the heart beat too quickly. If you were asked to run on a treadmill at a fast rate you would become tired pretty quickly. If you ask the heart to beat at a fast rate then it will also get tired. Good heart rate control both at rest and during exercise is therefore important. There is evidence emerging that heart failure can occur in some patients despite good rate control and that restoration of normal rhythm by catheter ablation can help the heart to recover.
   
   
3. Death – no one truly understands why patients with AF die but a number of studies have shown that even when you correct for other diseases patients with AF are more likely to die than patients in normal rhythm. The largest study of this effect, the Framingham study showed that AF doubled peoples mortality rates. Because we do not know why this happens we cannot be sure that any treatment we give will prevent it so although it seems likely that restoration of normal rhythm will reduce the chances of death there is currently no proof that this is the case.

Benjamin EJ, Wolf PA, D'Agostino RB, Silbershatz H, Kannel WB, Levy D. Impact of atrial fibrillation on the risk of death: the Framingham Heart Study. Circulation. 1998 Sep 8;98(10):946-52