Transvenous cryoablation versus radiofrequency ablation of the slow pathway for the treatment of atrioventricular nodal re-entrant tachycardia: a prospective randomized pilot study

Eur Heart J. 2004 Dec;25(24):2226-31. doi: 10.1016/j.ehj.2004.07.020.


Aims: This is a prospective, randomized study comparing transvenous cryoablation with radiofrequency (RF) ablation of atrioventricular nodal re-entrant tachycardia (AVNRT).

Methods and results: In this pilot trial, 200 patients with AVNRT were randomized to undergo cryoablation or RF ablation of the slow pathway. A 7 Fr 4-mm-tip cryocatheter (Cryocath) was used for cryomapping and cryoablation. Cryomapping was performed at the temperature of -30 degrees C to test the effect on the candidate ablation site. Following successful cryomapping, cryoablation was performed to produce an irreversible lesion by freezing to -75 degrees C. Procedural success, defined as elimination of the slow pathway or noninducibility of AVNRT, was achieved in 97/100 (97%) patients in the Cryo group vs. 98/100 (98%) patients in the RF group. No permanent complete AV-block occurred in either group. During a median of 246 days of follow-up, 8 patients in the Cryo group and 1 in the RF group had AVNRT recurrence. The cumulative incidence of primary endpoint (a combination of procedural failure, permanent complete AV-block and AVNRT recurrence) was significantly higher in the Cryo group than in the RF group (P=0.03, Log-rank test).

Conclusions: The results of this pilot study indicate that transvenous cryoablation using a 4-mm-tip cryocatheter is associated with a comparable acute success rate but a higher recurrence rate as compared with RF ablation in patients with AVNRT. Potential benefits of cryoablation for ablation of AVNRT need to be determined in a larger multi-centre trial.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Catheter Ablation / methods*
  • Cryosurgery / methods*
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Pilot Projects
  • Prospective Studies
  • Tachycardia, Atrioventricular Nodal Reentry / surgery*
  • Treatment Outcome