Sunday, March 25, 2007

Rise in Atrial Fibrillation

The study conducted in Minnesota has revealed that incidence of atrial fibrillation rose about 12 percent between 1980 and 2000. "This is a major problem for our country," said Dr. Teresa Tsang, senior author of the study to be published in Circulation: Journal of The American Heart Association. "Unless we are able to prevent atrial fibrillation, it will exact a major toll on our healthcare resources in the coming years."
Atrial fibrillation (AF or afib) is an abnormal heart rhythm (cardiac arrhythmia) which involves the two upper heart chambers (the atria). It is the most common cardiac arrhythmia. Atrial fibrillation is an abnormal heart rhythm originating in the atria. Instead of the impulse traveling in an orderly fashion through the heart, many impulses begin and spread through the atria and compete for a chance to travel through the atrioventricular node. This causes a rapid and disorganized heartbeat.

The risk of developing atrial fibrillation increases with age. An individual may spontaneously alternate between AF and a normal rhythm (paroxysmal atrial fibrillation) or may continue with AF as the dominant cardiac rhythm without reversion to the normal rhythm (chronic atrial fibrillation). Atrial fibrillation is often asymptomatic, but may result in palpitations, fainting, chest pain, or even heart failure. These symptoms are especially common when atrial fibrillation results in a heart rate which is either too fast or too slow. In addition, the erratic motion of the atria leads to blood stasis which predisposes to blood clots which may travel from the heart to the brain and other areas. Thus, AF is an important risk factor for stroke, the most feared complication of atrial fibrillation.

Rhythm control medications (antiarrhythmic drugs) help return the heart to its normal sinus rhythm and later maintain normal sinus rhythm. There are several types of rhythm control medications, including: Quinidex (quinidine); Pronestyl (procainamide); Norpace (disopyramine); Toprol, Lopressor (metoprolol); Tambocor (flecainide acetate); Rythmol (propafenone); Betapace (sotalol); Tikosyn (dofetilide) and Cordarone (amiodarone). These medications are effective in around 50 percent of patients, but may lose their effectiveness over time.