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.

• Congenital 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 heart.

• 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 stroke.

• 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 them.

• 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 Pneumonia
o Lung cancer
o Emphysema
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.