What are the risks of Atrial Fibrillation?


The main risk associated with AF is stroke. This occurs because the atria are fibrillating and not beating in a coordinated way. The lack of sufficient contraction means that the blood in the atria becomes stagnant and can form clots. These clots can break off and travel anywhere in the body, but most worryingly, they can travel to the brain and cause a stroke. A doctor will assess your personal risk of stroke, the chart below can help you to also do this:

Question Points Your Score
Are you over 75? 2  
Are you between 65 and 74? 1  
Do you have high Blood Pressure? 1  
Do you have Diabetes? 1  
Do you have Heart Failure? 1  
Do you have Vascular Disease? 1  
Have you suffered a Stroke (even a mild Stroke)? 2  
Are you Female? 1  
Total -  

Your annual risk of stroke rises from under 2% a year with no risk factors to over 10% a year for five or six. Most experts who have looked at this scoring scheme (the CHADS score) would suggest that the tipping point for your benefits on taking anticoagulation medication (warfarin) over its risks, is at a score of 2 or above. However, there are situations where, using the more complex clinician assessment already shown, that even with a score of below 2, anticoagulation (warfarin) may be recommended.

Heart Failure

Having an uncontrolled heart rate for long periods of time (weeks or months) can damage the heart and you should check with your doctor that your heart rate is controlled adequately. In extreme cases, often when the rate is very fast or when it happens in a damaged heart, AF can cause heart failure, which means that the heart becomes weak, as a result of the rapid rhythm. As the heart weakens, blood flows back into the lungs and affects the normal breathing pattern.

AF is also associated with a slightly increased risk of death although this is a very small risk and generally AF is not considered a life threatening disease in its own right. Why AF is associated with increased risk of death is not understood.