Causes of AF
Commonly, AF is due to:
- high blood pressure
- sleep apnea
- lung disease
- thyroid disease
- alcohol ingestion
- leaky heart valves
- congestive heart failure
- excessive stimulants such as caffeine
Often, however, no cause can be found.
The Role of the Cardiac Nervous System
The role of the nerves to the heart as a cause of AF is becoming better understood and more widely accepted. Most people with AF have it because of some other identifiable problem, such as longstanding high blood pressure, or a leaky heart valve, or others listed above. But some people have little apparent reason for AF; in some of these there may be an abnormality of the nerves that control the heart.
Experiments have shown that excessive nerve activity (the vagal nerves to the heart that usually slow the heart down) can make AF much more likely to occur, and that eliminating these nerves or reducing their activity makes AF less likely to occur. Interestingly, many of these nerves are right at the spots that the surgeons cut during the original Maze procedure, and where electrophysiologists cauterize during catheter ablation of AF.