Q: My doctor told me I have atrial fibrillation. Should I be on a slow beta-blocker?

Atrial fibrillation, also referred to as AF or Afib, is the most common type of irregular heartbeat. It is found in about 2.2 million Americans and increases with age. If you have AF, the impulse does not travel in an orderly fashion through the upper chambers of the heart, also known as the atria. Instead, many impulses begin simultaneously and spread through the atria. The firing of these impulses result in a very rapid and disorganized heartbeat. The rate of impulses through the atria can range from 300 to 600 beats per minute. This is not an effective process for the blood flow and the blood stagnates, causing blood clots. Blood clots can cause stokes.

In order to reduce the risk of stoke, cardiologist often prescribe a beta-blocker to slow the rate of the lower chambers of the heart, called the ventricle, between 50 and 100 beats per minute. If you have had atrial fibrillation for less than 48 hours, then your doctor may perform a procedure called cardioversion. This treatment will use either medicine or a low-voltage electrical shock (electrical cardioversion), to return the irregular heartbeat to a normal rhythm. If atrial fibrillation has lasted for more than 48 hours, attempting cardioversion could cause a stroke. In this case, you may need to take the anticoagulant (or blood thinner) medicine warfarin, commonly referred to as Coumadin, for several weeks before your doctor tries cardioversion. Taking anticoagulants reduces the chance that a clot might travel from the heart to the brain after cardioversion.