In the past AF was considered a completely benign condition, in other words a condition that is not harmful.
Doctors and other health professionals who have kept up to date however, warn you of the following risks associated with AF:
This is permanent or temporary damage to the brain caused by a loss of blood supply. It can present in many ways but commonly as weakness of the arm and/or leg on one side of the body, inability or difficulty speaking, loss of ability to swallow and loss of sight. AF is the commonest cardiac cause of stroke (see What is AF section for an explanation).
If you have AF your risk of stroke is higher if you have other additional risks for stroke. However the level of that risk is determined by your age and the presence of other medical problems; diabetes, high blood pressure, heart failure, coronary heart disease (angina or heart attack), previous stroke. This risk is greatly reduced by using anti clotting drugs like Edoxaban, Apixaban, Rivaroxaban or Dabigatran.
Risk of stroke is easily assessed using the CHADSVasc score which is the sum of the total number of risk factors the patient has.
- C=congestive heart failure (easily excluded using an echocardiogram) 1 point
- H=hypertension (even if well treated) 1 point
- A=Age >65 (1 point) >75 (2 points)
- D=Diabetes (1 point)
- S=stroke (2 points)
- Vasc=a vascular event like a heart attack (1 point)
- Being Female gives an additional point if over 65 years old.
Anticoagulants are very effective drugs (reduces stroke risk by 60%) however many patients are concerned about the risk of bleeding. Remember a stroke can be devastating causing permanent disability or death and preventing this with anticoagulants usually far outweighs the harm of the drug.
2. Heart failure:
This is a syndrome of breathlessness, fatigue and swelling caused by weakness of the heart muscle. AF causes heart failure by making the heart beat too quickly for too long. The heart is incredibly tolerant of this and even if there is evidence of heart failure associated with high heart rates, often slowing the heart down by giving a drug (betablocker or calcium channel blocker) that supplements the rate limiting effect of the AV node, will allow the heart function to recover. Good heart rate control both at rest and during exercise is therefore both important and very low risk treatment. Sometimes even if the heart rate is well controlled, heart failure and AF often may be associated, and we did the first of now several studies that show that restoration of normal rhythm by catheter ablation can help the heart to recover in some patients.
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 slightly 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.