New treatment for an irregular heart beat

March 17, 2010 3:32:00 PM PDT
It's one of the most common heart problems. Two-point-two-million Americans have an irregular heart beat, or atrial fibrillation.

If left untreated, it puts people at an increased risk of blood clots and stroke. Doctors are now using a new piece of machinery to help these hearts. It uses magnets to guide doctors into hard to reach places.

David Swigers' plan for retirement was traveling, but his heart problems got in the way. One episode happened mid-flight.

"Suddenly, I passed out and went into a-fib, and the flight attendant thought I was dying," Swigers explained.

David has atrial fibrillation. The upper chambers of his heart beat irregularly. It makes him tired and out of breath.

"It's like you've run a race and you're always feeling that feeling," he said.

Medication wasn't working, so his doctor recommended catheter ablation. Cardiologists thread a catheter from the groin to the heart and zap the abnormal heart tissue. Studies show its 60 to 80-percent effective. Dr. Shivkumar uses a new piece of machinery. Instead of guiding the catheter to the heart by hand, two large magnets do the job.

"So it catches hold of the very tip of the catheter so it gives a very high degree of precision and control," said Shivkumar, who is the director of UCLA's Cardiac Arrhythmia Center in Los Angeles.

From another room, cardiologists map out the heart in 3-D and use a joystick to guide the catheter to the exact problem spots.

"This technology is able to get into some nooks and corners of the heart which is harder to do by just hand manipulation," Shivkumar said.

Doctors say it reduces radiation exposure and increases control, but they're still collecting data to see if it works better than the traditional approach long-term.

A couple of months after the ablation, David has had one heart episode.

"Which is kind of a record for me over the last few years," he said.

He's hoping it's a record that lasts so he can get back into the groove of retirement.

Dr. Shivkumar says between 25 and 50-percent of patients require a second procedure for atrial fibrillation but hopes to reduce those numbers with the new magnet-based technique.

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BACKGROUND: More than 2.2 million Americans suffer from atrial fibrillation, or an irregular heartbeat. During atrial fibrillation, the heart's two small upper chambers, the atria, quiver instead of beating effectively. Blood isn't pumped completely out of them, so it may pool and clot. If a piece of a blood clot in the atria leaves the heart and becomes lodged in an artery in the brain, it causes a stroke. About 15 percent of strokes happen in people with atrial fibrillation. The likelihood of developing atrial fibrillation increases with age. Three to 5 percent of people over 65 have the heart condition. Doctors often first prescribe beta-blockers, calcium channel blockers and other drugs to try to improve the condition before resorting to surgical options such as installing a pacemaker or catheter ablation.

CATHETER ABLATION TO TREAT A-FIB: Catheter ablation is a minimally invasive procedure to treat atrial fibrillation that does not require open heart surgery. Catheters, or thin, flexible tubes, are threaded through the patient's blood vessels from the groin to the heart. Radiofrequency energy directed from the tube's tip heats and destroys the tissue causing the bad electrical signals. The procedure's risks include creating fluid in the lungs or around the heart, bleeding, clots and stroke. An international study found nearly two-thirds of people with atrial fibrillation experienced no symptoms one year after having a catheter ablation. Seventeen percent of those in the study treated for the condition with just medications reported being arrhythmia-free in the same period.

MAGNETS GUIDE CATHETER: Electrophysiologists are now using a new piece of technology in catheter ablations for atrial fibrillation. The Stereotaxis system uses powerful magnets positioned near the patient to guide the catheter to the exact problem spots, instead of guiding the tube by hand. Software maps a pathway through the patient's blood vessels and heart to the diseased heart tissue, and the doctor directs the ablation using a joystick and other controls from a control room. The magnets lead the soft catheter along the pathway by guiding its magnetic tip. It allows the physician to position the catheter in the precise location of the heart's malfunction. Doctors say it also reduces radiation exposure for the patient and the doctor. There are studies currently going on to determine if the magnetic approach to catheter ablation is more effective in treating atrial fibrillation compared to the traditional technique.


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