Health & Fitness

Treating irregular heartbeats through heat or freezing small area of heart tissue

When Gayle Dwyer’s rapid heartbeat landed her in the emergency room or sent her home from her job as a registered nurse, she knew she had to do something about it.

“I would get palpitations, they would come suddenly, be strong and stay for a long time,” Dwyer said. “It became very scary.”

Dwyer works in a cardiac catheterization lab at Memorial Regional Hospital. She and the patients she took care of had similar conditions.

“I was familiar with the situation and knew something needed to be done so I could continue working,” she said.

Mid-2014, Dwyer was diagnosed with supraventricular tachycardia, a condition that causes palpitations due to malfunctioning electrical pathways in the heart.

She underwent a procedure called ablation in November 2014 and hasn’t experienced a hammering heartbeat since.

“After I had my procedure, I would perform the same duties as before,” Dwyer said. “I can get a lot more accomplished now and feel good, not drained.”

The procedure maps the heart, finds where the electrical issue is located and destroys a small area of the heart tissue that causes the irregular heartbeat.

“People with irregular heartbeats are symptomatic. They feel weak, out of breath, light-headed and can’t exercise,” said Dr. John Cogan, medical director of adult cardiac electrophysiology at the Memorial Cardiac and Vascular Institute. “Now we can go inside the heart and pinpoint where these things are coming from.”

During ablation, a catheter is inserted through a blood vessel in the groin and guided to the heart. The electrode at the tip of the catheter transmits radio-frequency energy to the site of the faulty electrical pathway and burns the tissue, which restores the heart’s regular rhythm.

Ablation can be done by freezing the tissue instead of burning it. According to Cogan, cryoablation is done for safety purposes and is beneficial when performing the procedure on particularly sensitive parts of the heart. With cryoablation, the doctor can stop and move the catheter to a different area of the heart without anything happening to the tissue that was being frozen.

“The tissue thaws and everything goes back to normal,” he said.

Cardiologists throughout South Florida can perform these procedures.

Ablation is usually performed nonsurgically using a catheter, but it is sometimes performed as open surgery in combination with other treatments like bypass surgery, heart valve repair or valve replacement. Cogan said open chest procedures are rarely performed and mostly treat patients with atrial fibrillation.

“Open surgeries are also done when catheter procedures fail,” Cogan said.

Ablation treats atrial fibrillation, atrial flutter and ventricular tachycardias like Dwyer’s. While the procedure is done most frequently in the upper chambers of the heart, electrical issues in the lower chambers can also be treated with ablation.

The procedure’s success rate is higher in treating ventricular tachycardias and atrial flutters than it is in treating atrial fibrillation. According to Cogan, ventricular tachycardias and atrial flutter are a physical short circuit in a specific pathway in the heart that can be easily pinpointed.

“With AFib, the mechanism is much more disorganized,” Cogan said. “We have triggers in several areas of heart firing at the same time. We’re trying to get rid of multiple triggers, usually around back of left atrium, not a specific pathway.”

Destroying heart tissue, even if it’s to restore heart rhythms, might sound dangerous, but Cogan said it’s safe.

“For regular flutters, the amount of tissue we ablate is minimal,” he said. “It doesn’t affect blood flow.”

He did say that for patients that ablating could be a problem with patients who require multiple procedures.

“For AFib, we do extensive ablation in the back of the heart,” he said. “Too much ablation can make the heart stiff. That can cause shortness of breath and medication becomes necessary. But treating less severe heart rhythms is not a problem. ”

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