Ablation - stabilizing an irregular rhythm

By Darla Brown

On his way to Italy for college art history studies, a young patient visited his cardiologist for a checkup about his rapid heartbeat, which had been diagnosed as ventricular tachycardia of unknown origin.

“We had had to take him out of sports in high school and put him on a regimen of medication to regulate his heartbeat. It was emotionally devastating for him,” explains Anne Dougherty, M.D., professor of cardiology. “But when he returned for a follow-up visit years later, I asked him if he was interested in a newer, better treatment.”

That treatment is ablation – a procedure during which a catheter is threaded to the heart, usually via the groin, and energy is delivered to the area, destroying the problematic tissue.

“We were able to ablate the tachycardia, take him off of his medication, and put him on the plane,” Dr. Dougherty says. “Later I heard from him via e-mail that he was skydiving in Switzerland.”

Almost everyone has some heart arrhythmia, says Dr. Dougherty, which is defined generally as any irregularity in the cardiac rhythm; however, some are more troublesome and can result in severe symptoms that can lead to disability and/ or death.

Treating an irregular beat

Cardiac ablation has been used for the last 20 years to treat irregular heartbeats, says Bharat Kantharia, M.D., associate professor of cardiology.
“Historically, a direct current was used, but now radio frequency energy is used to permanently, irreversibly make changes in the tissue – causing cell death. You also can use ultrasound, cryoablation, and experimental forms are being investigated, such as microwaves – all delivering current from the catheter tip,” Dr. Kantharia explains.

Ablation has traditionally been used to eliminate supraventricular tachycardias – rapid heartbeats beginning in the upper chambers of the heart. This treatment also is making inroads to solve a growing problem – atrial fibrillation, an irregular, rapid heartbeat during which the heart may beat up to four times faster than normal.

A problem on the rise

More than 2 million Americans suffer from atrial fibrillation – and the number is increasing as America grays as it is more common in those ages 60 and up.

“Atrial fibrillation has been proven very challenging to cure, and we’ve learned to treat it better via ablation – it relieves symptoms and reduces patients’ dependence upon medication,” Dr. Dougherty says.

Using 3-D maps of the heart, treating atrial fibrillation through pulmonary vein isolation is done in the catheter lab with the patient lightly sedated but awake through the procedure, which takes 3 to 6 hours. With a team of cardiac fellows, nurses, and catheter specialists, the catheter monitors are inserted into the heart, revealing the heart’s interior, cellular rhythms. Experienced cardiologists use these maps to determine how much and where to ablate.

Ablation is not a first-line defense for A Fib, as it is called.
“It’s for those who are not responding to traditional medication. Because it’s such a widespread nuisance, there is a great interest in trying to find a better, curative procedure – it’s a treatment in evolution,” Dr. Dougherty says.

It is not just the aging population that is affected by irregular heartbeats. People of all ages may have palpitations. Some are inherited, like Wolff-Parkinson-White syndrome, or others may be the result of a structural problem or emerge following coronary disease.

“Atrial flutter and ventricular tachycardia respond very well to ablation,” Dr. Dougherty adds.

The diagnosis of these disorders is done via electrocardiogram (EKG) to determine the type and appropriate treatment. “If someone is having an arrhythmia every six months, it can be tricky – we can place a remote monitor on them or implant a device for monitoring,” Dr. Dougherty explains.

And just as the treatment is being refined, so are the clinical technologies.
“The next level will be to robotically control the catheter through the heart via a joystick using robotics,” Dr. Kantharia says.