Zap away atrial fibrillation?

Zap away atrial fibrillation?

Atrial fibrillation — called afib for short — is a rapid, irregular heartbeat caused by errant electrical signals in the heart’s upper chambers (atria). This heart rhythm disorder becomes more prevalent with age, affecting about one in 11 people ages 65 and older.

The chaotic heartbeat that characterizes afib usually comes and goes and may last anywhere from a few seconds to many hours — or much longer (see “Atrial fibrillation: Defined by its duration”). Although about 20% of people with afib don’t notice any symptoms, it can trigger a range of unsettling problems. These include a fluttering or thumping sensation in the chest, breathlessness, dizziness, anxiety, weakness, fainting, confusion, and fatigue.

 

Atrial fibrillation: Defined by its duration

Episodes of afib are often unpredictable and may be fleeting or last far longer. Over time, afib can become constant. Experts classify the disorder into three main categories based on its duration:

Paroxysmal. Episodes that occur intermittently (anywhere from daily to several times a year) but resolve spontaneously or with intervention within seven days of starting.

Persistent. An episode that lasts for longer than seven days. It will not resolve on its own and requires some type of treatment.

Permanent. Continuous afib that has lasted longer than a year.

 

Treatment goals and trends

Treating atrial fibrillation focuses on two main goals. One is to prevent stroke, the most feared complication of afib. During a bout of afib, blood pools inside the atria and tends to form clots, which can then travel to the brain and cause a stroke. To reduce this risk, many people with afib take an anti-clotting drug. The other goal is to tame the fast, irregular heart rate. Although certain medications (anti-arrhythmia drugs) can slow down the heart or help it stay in a normal rhythm, they aren’t always effective. But another option, a procedure called catheter ablation, is gradually becoming more widely used, says Dr. Paul Zei, director of the Comprehensive Atrial Fibrillation Program at Harvard-affiliated Brigham and Women’s Hospital.

“The most recent guidelines for treating atrial fibrillation have shifted catheter ablation more to the forefront of therapy decisions,” he says. During a catheter ablation, a doctor gently guides a thin, flexible tube (catheter) into a large vein and threads it up to the heart (see illustration).

 

Illustration by Scott Leighton. During catheter ablation, a device at the tip of the catheter emits energy that destroys (ablates) tiny patches of heart tissue responsible for the erroneous electrical signals that cause afib.

When quality of life suffers

Currently, catheter ablation is an option for people with either paroxysmal (intermittent) or persistent afib who have tried medications without success. “For people considering ablation, it really boils down to quality of life. Many people are truly disabled by their symptoms,” says Dr. Zei.

Some people with disabling symptoms from paroxysmal afib might undergo ablation even without trying drugs first, he adds. This shift stems from the observation that ablation tends to be more successful in people with paroxysmal afib than persistent afib. Experts are beginning to realize that afib is a progressive, chronic condition that becomes more challenging to treat as time goes on, says Dr. Zei. For people with permanent afib, the benefits of catheter ablation remain unclear.

The overall success rate for catheter ablation is about 75%. Sometimes, people undergo a second procedure if the first one doesn’t work, which boosts the success rate to nearly 90%. The risks range from bleeding at the catheter insertion site to serious but very rare complications, such as heart attack or stroke. In addition, some people must still take anti-arrhythmic drugs after the procedure; the drugs tend to work better following an ablation.

People often wonder if they also need to take anti-clotting drugs after an ablation, says Dr. Zei. These drugs help prevent dangerous blood clots that can lead to a stroke. Because afib increases the risk of stroke by up to five times, doctors often prescribe anti-clotting drugs to people with afib. But having an ablation does not necessarily change the equation. The decision to prescribe anti-clotting drugs depends on a person’s overall risk of stroke, which takes into account age as well as other health conditions, such as high blood pressure, diabetes, or a previous heart attack or stroke.

 

This article was originally posted by Harvard Health on March 16, 2018.