[Radiofrequency ablation in the treatment of atrioventricular nodal reentrant tachycardia and preexcitation syndrome].

Radiofrequency ablation is a standard tool for treatment of cardiac arrhythmias. It is most frequently performed in patients with nodal tachycardia, atrial flutter, and accessory atrioventricular pathway. The site for effective ablation is selected using an anatomical or electrophysiological method or both. In patients with nodal tachycardia slow pathway ablation is preferable due to lower risk of atrioventricular block and lower frequency of recurrent tachycardia as compared with fast pathway ablation. The factors determining the site of ablation and its efficacy are Jackman's and Haissaguerre's potentials and the type of extrasystoles during the procedure. The presence of residual slow pathway conduction is not a major prognosticator of late arrhythmia recurrence. In patients with the accessory pathway ablation can be performed by destructing the ventricular entry of the accessory pathway from the femoral approach or the atrial entry from the transseptal approach. The choice of the technique depends on the experience and preferences of the operator. The localization of an effective ablation site is related to the following electrophysiological parameters: accessory pathway potential, VA interval, V-Delta interval, stability of the electrode and electrogram.