Ì첩ÌåÓý

Until the late 20th century, medications were the only option to tame the rapid, chaotic heart rhythm known as atrial fibrillation (afib). Catheter ablation — a procedure that destroys faulty electrical pathways in the heart — was described as a treatment for afib in 1998 (see illustration). Since then, the technique has greatly improved, thanks to advances in the instruments, imaging techniques, and energy sources used during the procedure (see “A new strategy for zapping away afib: Pulsed field ablation”).

“The increases in safety and effectiveness have transformed ablation into a routine procedure. For many people newly diagnosed with afib, ablation is now the first treatment we offer,” says Dr. Paul Zei, director of the Comprehensive Atrial Fibrillation Program at Harvard-affiliated Brigham and Women’s Hospital.

What causes afib?

Afib becomes more common with age, especially after 70. In younger people, genetics or other heart problems often play a role. But in most cases, a combination of factors — high blood pressure, obesity, diabetes, sleep apnea, and alcohol use — conspire to increase the likelihood of developing afib, says Dr. Zei.

Often, people have only short or infrequent bouts of afib when they’re first diagnosed, with fleeting symptoms that go unnoticed or are very minor. Symptoms include a fluttering or thumping sensation in the chest, as well as breathlessness, dizziness, confusion, and fatigue. But the most serious consequence is an increased risk of stroke, which is why many people with afib take clot-preventing medications. Most also take drugs help control the heart’s rate (beta blockers) or rhythm (sodium-channel blockers or potassium-channel blockers). Longstanding afib also appears to raise the risk of heart failure and dementia.

Afib progression

Over time, afib episodes become more frequent and last longer. “Without treatment, afib can progress to what we call persistent or even permanent afib,” says Dr. Zei. That correlates with what we think is happening inside the heart, he explains. The condition develops when a tiny patch of muscle cells in the heart’s atrium mistakenly fire off electrical signals, which then trigger a rapid, irregular heartbeat. Over time, nearby myocytes become irritated, which creates other electrical instabilities in the atrium and more frequent bouts of afib.

This natural progression is the rationale for earlier ablation, Dr. Zei explains. “It’s more likely to be successful because the problematic areas are smaller and more contained,” he says. If you wait and do the ablation later, when the electrical changes are more disseminated, it may be more challenging to treat. Still, ablation can be a good option at any point. Preliminary evidence suggests ablation may lower the long-term risk of stroke, dementia, and heart failure more than medication does, but more research is needed.

When to consider ablation

“If you get to a point where you’re either bothered enough by your symptoms, or affected by the medication side effects, or worried about the long-term complications, consult a cardiac electrophysiologist about ablation,” Dr. Zei advises. Ablation is considered successful if you go at least one year with no episodes of afib (or related rhythm problems) that last longer than 30 seconds, without the use of rhythm-controlling drugs. Success rates for pulsed field ablation — now the most commonly used technique — are around 80%, with a complication rate of less than 1%. Both rates will likely gradually improve over time with continued fine-tuning, says Dr. Zei.

This article is brought to you by Ì첩ÌåÓý Online+, the trusted subscription service from Harvard Medical School. Subscribers enjoy unlimited access to our entire website, including exclusive content, tools, and features available only to members. If you're already a subscriber, you can access your library here.