What Causes Atrial Fibrillation

  • “Why Me?” 

    Just last week one of my patients was in the office asking this important question.  Carl was a man in his forties, balding, portly with a belly that hung at least a foot over his belt.  (I’ve changed his identity.)  Carl worked as a supervisor for a local trucking company.  Office work kept him extremely busy and stressed out, but he wasn’t all that physically active.

    Carl had been sent to a cardiologist after being newly diagnosed with Atrial fibrillation.  He suffered from fatigue and annoying skipped heartbeats that made it extremely difficult for him to fall asleep at night.   

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    Indeed, a very common complaint of people with Atrial Fibrillation is that they feel distressed because of severe palpitations when they lay down at bedtime. 

    Because Carl was fairly young and saw himself in relatively good health, he was wondering why he had been afflicted with this common heart rhythm problem. 

    “Why me doc?”  he asked.  “I don’t smoke.  I don’t have any real heart disease that I know about.  Why should I have this heart rhythm problem?” Although Carl didn’t suffer from significant heart problems, he did have high blood pressure and in addition consumed a moderate amount of alcohol on a weekly basis.

    The question of why someone gets Atrial Fibrillation (AF) is a very good one. 
    In my last blog post, I began this discussion about Atrial Fibrillation, because it troubles so many people.  It is estimated that one out of every 140 people in America has Atrial Fibrillation. (ACC/AHA/ESC 2006 Guidelines for the Management of Patients With Atrial Fibrillation).

    Atrial Fibrillation is an extremely costly medical problem.  It is estimated that over 15 billion dollars are spent every year on Atrial Fibrillation in the US. 

    Atrial Fibrillation is an irregular heart rhythm that can lead to strokes for people who go untreated.  Because the upper chambers of the heart lose their natural organized pumping ability, blood can stagnate in these chambers much like eddies in a river where leaves and branches in the water coalesce. Stagnation in this way can cause the formation of blood clots. 

    Sometimes the blood flow is so slow that the blood can actually be seen to be swirling.  Cardiologists call this “smoke.”  Strokes can happen when blood clots break loose and travel to the brain.

    Carl’s question, “Why Me?”  is a good one because the treatment of Atrial Fibrillation is often based on understanding why this rhythm has occurred. 

    Before I go any further let me give you some definitions of Atrial Fibrillation that may come up in the way your doctor decides to treat your condition. 

    Atrial Fibrillation can be considered “paroxysmal” when it happens intermittently and stops on its own without treatment.  It can also be “recurrent” happening again and again with 2 or more episodes of Atrial Fibrillation.   If the Atrial Fibrillation lasts more than 7 days it is called “persistent.” The duration of AF refers both to individual episodes and to how long a person has been troubled by the rhythm problem. 

  • By and large cardiologists will recommend long-term treatment with anticoagulants (warfarin) when your AF is “recurrent” or “persistent.”  Even in cases of “paroxysmal” Atrial Fibrillation long-term anticoagulation may be indicated and recommended by your cardiologist.

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    Why Me?  Or What Causes Atrial Fibrillation

    Carl’s question as to why he was relatively healthy and still got AF is a good one.  The cause of Atrial Fibrillation is generally believed to be scaring of the atrial chambers and loss of atrial muscle mass due to damage of the heart.

    The medical term for scarring of the atrium is called fibrosis.  Scarring (fibrosis) is caused by numerous conditions that afflict the heart. 

    Causes of Atrial Fibrillation

    High blood pressure
    Valvular heart disease (Leaky or narrowed heart valves)
    Coronary heart disease- cholesterol blockage of arteries
    Heart failure
    Weakened heart muscle- cardiomyopathy
    Atrial dilation (enlargement) from any cause: obesity, Mitral regurgitation, Tricuspid Regurgitation, Aortic Stenosis, Mitral Stenosis, hypertrophic cardiomyopathy,
    Aortic Regurgitation
    Pulmonary Vein dilation
    Inflammatory conditions of the heart
    Even aging may lead to Atrial Fibrillation

    Ultimately, damage and abnormality of the atria upsets the normal conduction of electrical activity through the heart.  Many theories exist as to “why” Atrial Fibrillation is actually triggered and then become sustained.  These reasons don’t influence treatment.

    For people with Atrial Fibrillation the important thing is to try to determine if there is something they can do to alter/prevent the conditions that cause this unfortunate rhythm problem.

    In Carl’s case, he was overweight, suffered from high blood pressure, and consumed a
    large amount of alcohol on a regular basis.   Hypertension and excessive alcohol consumption are known to be implicated in Atrial Fibrillation.  Hypertension can be controlled by medications, exercise, and other lifestyle changes.   A person can choose to discontinue or reduce their alcohol consumption.  

    So in theory, Carl might be able to successfully eliminate his Atrial Fibrillation and return to a normal cardiac rhythm. 

    Some of the other causes of Atrial Fibrillation can also be treated.  Valvular conditions, coronary heart disease, and even heart failure can be amendable to therapy.  Consult your doctor to find out what may have caused your Atrial Fibrillation.

    “Why me” is a common question asked by people with Atrial Fibrillation. 

    I hope this has increased your interest in this common cardiac problem.

    Dr. Kirk Laman
    Wholehearted Cardiologist

Published On: July 27, 2009