Transcatheter ablation and modulation of AV node and anomalous pathways

We report our experience of transcatheter ablation in pts with SV tachyarrhythmias. We started our experience with DC shock ablation in 1987 and moved toward RF current in mid 1991. Up to now 80 pts with drug refractory arrhythmias have been treated with this technique (DC: 70 pts, RF 10 pts). AV nodal ablation: Sixty pts with paroxysmal or chronic A.F. were referred for AV junctional ablation. AV block was produced in 58/60 (96,6%) and subsequently VVI RR or DDD RR PM were implanted. At a mean follow up of 19,9 months AV block persisted in 58; exercise capacity and quality of life significantly improved in more than 85% of the pts. Modification of AV junction in AV nodal reentry tachycardia: Nine consecutive pts underwent perinodal modulation. In 9/9 (100%) retrograde conduction was abolished or significantly impaired. One pt had complete AV block and had PM implanted. At a mean follow up of 12,4 months 8 pts had no recurrence of SVT, 1 pt developed paroxismal A.F., successfully treated with drugs. Ablation of accessory pathways: Eleven pts with overt (7) and concealed (4) pathways underwent transcatheter ablation of Kent bundle (5 posteroseptal, 3 anteroseptal, 1 midseptal, 1 right lateral, 1 left posterior). The procedure was effective in 9/11 pts (84,8%). Two pts resumed conduction of anomalous pathways that were subsequently ablated by the surgeon. One third degree AV block occurred and a PM was implanted. In conclusion the technique appears to be safe and effective, even if not simple and time consuming, and hopefully the treatment of choice of many SV tachyarrhythmias.