Atrial fibrillation alternatives
By the faculty of Harvard Medical School for The Harvard Medical School Adviser

Q: I take Inderal to treat my atrial fibrillation, but it makes me really tired. Are there other drugs that don't cause this side effect? What about nondrug treatments?

A: Propanolol (Inderal) belongs to a class of drugs known as beta blockers, which help slow the heartbeat. Normally, the heart beats with a steady rhythm, thanks to regular electrical signals that travel through the heart. But in people with atrial fibrillation (AF), the signals become irregular and rapid. The heart's upper chambers (atria) quiver, causing the heart to race. As a result, the heart pumps blood less efficiently, which is why some people with AF may feel dizzy, weak or tired.

Unfortunately, beta blockers -- one of the most common treatment for atrial fibrillation -- can also cause fatigue. For reasons doctors don't fully understand, some people feel tired when taking one type of beta blocker but not another. So you should talk to your doctor about switching to a different beta blocker. Alternatives include metoprolol (Lopressor, Toprol-XL), nadolol (Corgard) and atenolol (Tenorim).

If there is no change after you've given the other beta blockers a try, then ask your doctor about switching to a different class of medications. The calcium-channel blockers are probably the first to consider. Like the beta blockers, they can do a good job of slowing the heart down, but they don't usually restore a normal rhythm. Calcium-channel blockers include verapamil (Calan, Isoptin, others) and diltiazem (Cardizem, others).

Another option is a drug that helps correct the heart's faulty rhythm. The most common is amiodarone (Pacerone, Cordarone). But this medication can produce many side effects, including coughing, headaches and tingling in the fingers or toes. Sometimes, people are hospitalized when they begin taking these drugs so doctors can monitor them for side effects.

Most people with AF must take medications know as anticoagulants ("blood thinners"). These drugs help prevent blood clots, which can cause strokes -- a serious complication of atrial fibrillation. The most common is warfarin (Coumadin). Finding the right dose can be tricky. It has to be high enough to prevent blood clots but low enough to avoid the risk of bleeding. People taking warfarin must have frequent blood tests to see whether their blood is in that safe range and adjust their dose, if needed.

Several other treatments are available for atrial fibrillation. One technique, known as cardioversion, is done under sedation or anesthesia and uses an anti-arrhythmic drug or an electrical shock to the chest. This interrupts the heart's abnormal rhythm and helps reset a normal rhythm. For a person who has had AF for only a few months, the success rate is high -- up to 90 percent in some studies. Cardioversion is less effective for people who have had the condition for a longer time. The technique is safe and has a low complication rate.

In some cases, the underlying abnormality in the heart's electrical system that causes AF can be permanently corrected using highfrequency radio waves (see illustration). A special instrument is passed through a vein in the groin and threaded up to the heart. The idea is to create scar tissue that blocks the unwanted electrical signals that trigger atrial fibrillation. A 2005 study found that 87 percent of subjects who underwent the procedure, called catheter ablation, had no problems with AF after one year.

Surgery is another possibility, but usually only as a last resort. Known as a Cox Maze procedure, this openheart operation involves series of small incisions in the atria that interrupt and channel the erratic electrical signals that cause atrial fibrillation. The surgeon also removes a small pocket of tissue in the left atrium that is a prime site for blood clot formation. In hospitals where it is performed regularly, the Cox Maze stops AF more than 80 percent of the time, for up to 10 years. It also prevents stroke without the need for warfarin. But because of its risks, doctors rarely recommend it unless a patient needs open-heart surgery for other reasons.

Some surgeons are now doing modified Cox Maze surgeries using slender instruments inserted through small incisions in the side of the chest. These procedures are sometimes referred to as "mini-Mazes." But they're actually more like catheter ablation than Cox Maze surgery. Mini- Maze surgeons use radio waves, ultrasound, or other techniques to destroy tissue. The procedure hasn't been around long enough to determine its safety and effectiveness. For now, it should be performed only at medical centers and by surgeons with the most experience in this new technique.

New medical and surgical therapies have improved the outlook of patients with AF. It's good news that won't set the heart aflutter.

Copyright 2007 the President and Fellows of Harvard College. Developed by Harvard Health Publications (www.health.harvard.edu). Distributed by UFS. Submit questions to harvard_ adviser@hms.harvard. edu.