Atrial fibrillation (AF) is the most common, abnormal rhythm of the heart.
The heart contracts (beats) and pumps blood with a regular rhythm, for
example, at a rate of 60 beats per minute there is a beat every second.
The heart may beat faster or slower with a shorter or longer interval
between beats, but at any one rate the interval between beats is
constant. This regular rhythm occurs as a result of regular electrical
discharges (currents) that travel through the heart and cause the muscle
of the heart to contract. In atrial fibrillation, the electrical
discharges are irregular and rapid and, as a result, the heart beats
irregularly and, usually, rapidly.
Atrial fibrillation is
common; half a million new cases are diagnosed yearly in the U.S., and
billions of dollars are spent annually on its diagnosis and treatment.
What are the Causes of Atrial Fibrillation?
Atrial fibrillation is closely linked with age. The older we get the
higher our risk is of developing it. It is extremely rare for atrial
fibrillation to develop in younger patients, unless they have an
underlying heart condition. Experts say there are many cases in which
the cause of the atrial fibrillation was never found.
Here is a list of the most common causes:
• Hypertension - high blood pressure.
• Coronary artery disease - also known as coronary heart disease.
Plaque builds up inside the coronary arteries. These arteries supply the
heart muscle with blood that is rich in oxygen.
heart disease - problems with the heart's structure which are present at
birth. This could include defects to the heart's interior walls, the
valves, or blood vessels that carry blood to and from the heart.
Congenital heart defects alter the normal flow of blood through the
• Mitral valve disease - the abnormal leaking of blood
through the mitral valve, from the left ventricle into the left atrium
of the heart.
• Cardiomyopathy - a serious disease in which the heart muscle becomes inflamed and doesn't work as well as it should.
• Pericarditis - inflammation of the pericardium - a protective lining that surrounds the heart.
• Previous heart surgery - a significantly higher percentage of
patients who have had heart surgery develop atrial fibrillation,
compared to other people.
• Hyperthyroidism - the thyroid gland is overactive.
• Sleep apnea - this is a common disorder in which the patient has one
or more pauses in breathing, or shallow breathing, during sleep.
Obstructive sleep apnea commonly causes high blood pressure
(hypertension), which in turn raises the risk of heart problems and
• Alcohol abuse - regular, excessive, long-term
consumption of alcohol is closely linked to a higher risk of developing
atrial fibrillation. A study carried out by scientists at Beth Israel
Deaconess Medical Center showed that risk of atrial fibrillation was as
much as 45 percent higher among heavy drinkers than abstainers.
• Smoking - smoking has been linked to several heart problems, including atrial fibrillation.
• Excessive caffeine consumption - this could include too many coffees,
energy drinks, and or sodas (fizzy drinks). Many sodas have caffeine in
• Atraial flutter - this is similar to atrial
fibrillation, however abnormal heart rhythms of the atria are less
chaotic and more organized than in atrial fibrillation. Atrial flutter
can develop into atrial fibrillation.
• Several types of chest infections and conditions:
o Lung cancer
o Chest infections
o Pulmonary embolism
o Carbon monoxide poisoning
How is atrial fibrillation treated?
The treatment of atrial fibrillation is multi-faceted and involves
1. reversing the factors that cause atrial fibrillation,
2. slowing the heart rate with medications,
3. preventing strokes,
4. converting atrial fibrillation to a normal heart rhythm with medications or electrical shock,
5. preventing the recurrence of atrial fibrillation with medications, and
6. using procedures (for example, pacemakers, defibrillators, surgery) to prevent episodes of atrial fibrillation.