By Thomas Lee

Medtronic Inc. (NYSE: MDT) said patients suffering from atrial fibrillation (AF), or irregular heart quivering, reported significantly less symptoms after using its cryoablation technology.

At the Heart Rhythm Society's annual scientific conference, the Fridley, Minnesota -based company continued its systematic campaign to scientifically validate its Artic Front Cardiac Cryoablation Catheter system by releasing the latest results from its pivotal STOP AF clinical trial of 275 patients.

Medtronic reported the number of patients reporting AF symptoms, including fatigue, rapid heart beat, difficulty breathing, and fainting, dropped 80 percent after 12 months. In March, the company said nearly 70 percent of the patients had no AF one year after treatment compared to just 7.3 percent of patients who received drugs but do not respond well to such therapy.

Medtronic has high hopes that its Artic Front therapy, the first of its kind in the United States, can grab a significant piece of the estimated $2 billion global AF market, which has been growing at a double-digit rate the past few years.

The company acquired the technology in 2008 when it purchased CryoCath Technologies Inc. for about $380 million. The Canadian company makes catheters (tubes) and balloons that can deliver subzero temperatures to the heart. The technology restores normal electric signals by freezing the tissue or pathways behind the irregular quivering.

About 2.2 million Americans suffer from AF, in which the two small upper chambers of the heart quiver instead of beat normally, according to the American Heart Association. When the patients heart is not pumping effectively, blood pools clot and get lodged in the brain, causing strokes.