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Heart 89:1091-1092 doi:10.1136/heart.89.9.1091
  • Scientific letters

Comparison of radiofrequency versus cryothermy catheter ablation of septal accessory pathways

  1. G P Kimman,
  2. T Szili-Torok,
  3. D A M J Theuns,
  4. J C Res,
  5. M F Scholten,
  6. L J Jordaens
  1. Department of Cardiology, Thoraxcentre, Erasmus University Medical Centre Rotterdam, Rotterdam, Netherlands
  1. Correspondence to:
    Dr G P Kimman, Department of Clinical Electrophysiology, Bd 402, Thoraxcentre, Erasmus MC, Rotterdam, Dr Molewaterplein 40, 3015 GM, Rotterdam, Netherlands;
    g.kimman{at}erasmusmc.nl
  • Accepted 19 May 2003

Approximately 30% of all accessory pathways are located in the “septal” area. As these pathways are close to the atrioventricular node, there is an increased risk of right bundle branch block or inadvertent complete atrioventricular block during catheter ablation.1 Lesions created by radiofrequency (RF) energy inevitably involve some degree of tissue disruption and are irreversible.

As cryothermy energy has the ability to reversibly show loss of function of tissue with cooling (“ice mapping”) at less negative temperatures, and progressive ice formation at the catheter tip causes adherence to the adjacent tissue, this ablation method potentially has advantages over RF for safe ablation of septal accessory pathways.2–4 In this retrospective study we compare transvenous RF with cryoablation in patients with septal accessory pathways.

METHODS

Between January 2000 and October 2001, 15 patients were treated with RF and the next consecutive nine patients with cryoablation for septally located accessory pathways. The final classification of the accessory pathways was made according to the successful ablation site on fluoroscopy.

A standard electrophysiological study was performed and, after confirmation of the presence of an accessory pathway, transvenous RF or cryoablation was carried out.

Mapping was performed beginning at the anteroseptal region at the His deflection down to the coronary os and further to the right posterior region. For both energy forms standard techniques were used to identify prospective ablation sites. For cryoenergy procedures, initially ice mapping was done by cooling to −30°C for a maximum of 80 seconds with the use of a 7 French cryocatheter (Freezor, curve 3, CryoCath Technologies Inc, Montreal, Quebec, Canada). …