SLEH treats irregular heartbeat with novel minimally invasive cold cryoballoon technology

Mar 21 2011

A physician affiliated with Texas Heart^® Institute (THI) at St. Luke's Episcopal Hospital (SLEH) is the first in Houston and among the first in the nation to treat patients for an irregular heartbeat with a new, minimally invasive cryoballoon technology that uses cold rather than heat to interrupt faulty electrical circuits in the heart.

“The current way of performing ablation utilizes radiofrequency to create small lesions to form a circle around the pulmonary vein with the heart moving”

In January, THI cardiac electrophysiologist J. Alberto Lopez, MD, used the Arctic Front Cardiac CryoAblation Catheter System (Arctic Front) to perform ablations on two women with refractory recurrent symptomatic paroxysmal atrial fibrillation (PAF), a serious heart rhythm disorder that affects millions of Americans. Approved for use by the FDA on December 17, 2010, Arctic Front is the first cryoablation system indicated to treat PAF.

The first patient, a 54-year-old Houston resident, was the typical patient for whom this technology is recommended, Lopez said.

"She has previously seen three other doctors and taken four different medications, which either she did not tolerate well or did not work," he added. "Although the irregular heartbeat comes and goes, she was highly symptomatic, meaning she feels terrible, and the condition significantly affected her quality of life."

The second patient had a similar medical history, Lopez said.

Atrial fibrillation (AF) is an irregular quivering or rapid heart rhythm in the atrial (the upper chambers) of the heart. PAF is a type of AF in which the irregular heartbeats start and stop suddenly on their own, and can last for minutes or days at a time. In a catheter ablation, a physician aims to stop the rapid beating by ablating, or blocking, the conduction of AF by destroying the faulty electrical circuits in the heart.

Unlike traditional ablation treatments that use radiofrequency, or heat, to destroy faulty electrical circuits in the heart, Arctic Front uses a freezing technology, with a coolant delivered through a balloon catheter. This permits the catheter to adhere to the tissue during ablation, allowing for greater catheter stability.

"The current way of performing ablation utilizes radiofrequency to create small lesions to form a circle around the pulmonary vein with the heart moving," Lopez said. "It requires the use of high-tech, 3-D mapping to guide the delivery of the lesions. It's difficult to do, and physicians increasingly are using robotics to perform the procedure."

The cryoballoon procedure, on the other hand, is simpler, demands much less high-tech equipment and is cleaner, he said.

"With cryo, the balloon adheres to the heart and does not move. There is less chance of unintended damage, and there's less chance of clotting," according to Lopez. "The cryoballoon catheter sticks to the heart and makes a circular lesion all at once. In most cases, you only have to deliver one or two applications of energy to achieve that, rather than the 40 or 50 small ones next to each other without leaving gaps that the heat method uses."

"Cryo also produces the lesions slowly," he said. "So if you see something you don't like, you can stop."

Lopez has been a clinical investigator on cryoablation technology for the last five years and has traveled internationally to train with other colleagues on the technology. Lopez also previously served on the advisory board for the initial developer of the cryoballoon system and has recently been appointed to the advisory board for its successor company.