Atrial fibrillation (AF), also called A Fib, is an irregular, usually rapid heart rhythm (arrhythmia), that originates in the upper area (atria) of the heart due to abnormal electrical cardiac impulses that make the heart "quiver." Consequently, the two upper atrial chambers beat in an irregular manner out of sync with the two lower ventricle chambers, which may produce poor blood circulation to the body as well as weakness, shortness of breath and heart palpitations. The American Heart Association states that 2.2 million Americans have AF, the most common cardiac arrhythmia, especially in those older than 65 years of age.
Causes: Cardiac
The heart normally beats around 60 to 100 beats a minute, yet for AF, the heart rate can range from 100 to 175 beats per minute. While many factors may contribute to arrhythmias, AF commonly presents due to some cardiac condition or disease such as valvular heart disease, congenital cardiac disorders, coronary artery disease, hypertension, and pericarditis (inflamed lining of heart). Other precipitating conditions include: cardiomyopathy or cardiac muscle disease; sick sinus syndrome, that is, dysfunction of natural impulse firing system; and acute myocardial infarction (heart attack) as well as having had cardiac surgery.
Causes: Non-Cardiac
It is possible for atrial fibrillation to occur in the absence of any indicated heart disease. Some possible causes that are not cardiac-induced can include hyperthyroidism (over-active thyroid), diabetes, obesity, hypokalemia (low potassium) and viral processes. Other conditions associated with AF are chronic obstructive pulmonary disease, lung cancer, pneumonia and pulmonary embolism (lung blood clot). Hypothermia as well as sleep apnea may precipitate AF.
Causes of Excess
There are medical events where otherwise healthy individuals infrequently experience short episodes of AF. Such events may have common triggers of excess, for example, excessive alcohol intake may lead to AF or what is sometimes referred to as holiday heart. Other typical AF triggers, in addition to alcohol, may include: drugs, tobacco and caffeine. If known triggers are avoided, so too, may be episodes of atrial fibrillation.
