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Cryoablation for Arrhythmias

Cryoablation Uses Intense Cold to Ablate Very Small Areas of Heart Tissue

Ablation using heat has been standard therapy in the treatment of certain arrhythmias for some time.

But a newer form of catheter-delivered therapy for cardiac arrhythmias is being used at Cedars-Sinai, called cryoablation, which exposes the faulty tissue to sub-zero temperatures to destroy it. This approach is especially suited for treating certain patients with high-risk arrhythmias, according to Walter F. Kerwin, M.D., a cardiologist in Cedars-Sinai's Cardiac Electrophysiology section.

Catheter cryoablation uses intense cold (to -90 degrees Celsius) to ablate very small, carefully selected areas of heart tissue that are causing the irregular rhythm. The effects of cryoablation occur slowly, over minutes. In contrast, radiofrequency ablation heats the defective tissue to destroy it within seconds.

Cryoablation is performed in a two-step approach that gives physicians an opportunity to assess the cooling effect on both normal and dysfunctional pathways. In the first step, the arrhythmia is "mapped," with the tissue being cooled from normal body temperature (37 C) to 0 C. If a normal pathway is observed to stop conducting, the catheter can be thawed and the pathway will return to normal conduction. If cooling is seen to affect only the arrhythmia, however, the temperature can be further reduced to sub-zero temperatures to permanently eliminate the pathway.

Because the cryoablation procedure takes this two-step approach and the ablation takes minutes to complete, it is a potentially safer way to correct arrhythmias than radiofrequency ablation in patients whose normal conduction pathway and diseased conduction pathway are close to each other, said Dr. Kerwin, who uses catheter cryoablation to treat 95 percent of his patients who need ablation for their cardiac arrhythmias.

Dr. Kerwin is currently the principal investigator for an FDA study to evaluate the safety of treating patients who have atrial fibrillation with a new cryoablation catheter system as compared to medication. Cedars-Sinai is the only center in the Southwest and one of only eight centers in the U.S. chosen to participate in this study. For more information, contact Dr. Kerwin at Walter.Kerwin@cshs.org.