Transcatheter radiofrequency ablation of atrioventricular by-pass tracts--a definitive cure of Wolff-Parkinson White syndrome.

UNLABELLED

Patients with an accessory atrioventricular pathway (AAVP) may have to face either life-threatening arrhythmias or life-long antiarrhythmic drug treatment with the associated expense and morbidity, to which some may be refractory. The actual refinement of radiofrequency (RF) ablation technique has dramatically changed the management of these patients. The aim of this study is to describe the results of transcatheter RF ablation of AAVP in 29 consecutive patients with recurrent and/or drug refractory tachyarrhythmias mediated by AAVP. After an approximate localization of the AAVP according to Arruda et al. ECG algorithm, the precise identification of the site of AAVP was attempted. This was accomplished by mapping the mitral and tricuspid annuli. The tricuspid annulus was mapped directly using deflectable multielectrode catheters and the mitral annulus was mapped by means of a multielectrode catheter inserted in the coronary sinus. For finer localization we looked for AAVP activation potentials recorded from the ablation catheter. Mapping evaluation was made by means of BARD LAB SYSTEM 24 EP laboratory: 14 patients had left free-wall AAVP, 11 patients had posteroseptal AAVP and 4-midseptal AAVP. RF energy was delivered (30-40 W for 30 sec) by an Osypka HAT 200 S generator. The procedure lasted a mean 150 min and the maximum number of applications in successful sessions was 9. Twenty patients out of 29 (68.97%) were successfully ablated: 10 in the left free-wall group (71.43%), 7 in the posteroseptal group (63.64%) and 3 in the mid-septal group (75%). These lower figures are explained by the inclusion of the "learning curve" patients. For the patients of the last period the success percentage was of 90. The single complication was an arterial embolization during an arterial approach for ablation. After a mean 206-day follow-up no return of accessory pathway conduction was noticed.

CONCLUSION

Transcatheter RF ablation of AAVP is a safe and effective therapeutic modality in selected patients.