Safety and efficacy of cryoablation of atrial tachycardia with high risk of ablation-related injuries

The purpose of this study was to evaluate the safety and efficacy of cryoablation as an alternative to radio frequency (RF) ablation in high-risk-located atrial tachycardia (AT). Between 2004 and 2007, 164 patients underwent catheter ablation due to AT at our institution. Twenty-six of these patients (22 women and 4 men), median age 58 years (range 14-76), were considered having high-risk-located AT and were treated by cryoablation. Seven patients had failed prior RF ablation due to high risk of complications. The AT foci distribution was: close to the AV node (n = 14), vicinity of the sinus node (n = 7), and crista terminalis adjacent to the phrenic nerve (n = 5). Cryomapping, using a 6 mm tip catheter, at -30 degrees C was performed before ablation with a goal temperature of -80 degrees C for 240 s. Acute success rate was achieved in 25/26 patients (96%). During a follow-up of 493 +/- 258 days, three patients had recurrences. Two of these underwent a second successful cryoablation procedure. Long-term success rate was 92%. Phrenic nerve palsy occurred in two patients with complete recovery after 1 day and 5 months, respectively. Cryoablation of high-risk-located AT foci is a safe and effective alternative to RF therapy.