CATHETER ABLUTION OF PERMANENT JUNCTIONAL RECIPROCATING TACHYCARDIA WITH RADIOFREQUENCY CURRENT

Objectives. This study evaluated accessory pathway location, its relat ion to retrograde P wave polarity on the surface electrocardiogram and radiofrequency ablation efficacy and safety in a large group of patie nts with permanent junctional reciprocating tachycardia. Background. P ermanent junctional reciprocating tachycardia is an uncommon form of r eciprocating tachycardia, almost incessant from infancy and usually re fractory to drug therapy. It is characterized by RP > PR interval and usually by negative P waves in leads II, III, aVF and V-4 to V-6. Retr ograde conduction occurs through an accessory pathway with slow and de cremental properties. Although this accessory pathway has been classic ally located in the posteroseptal zone, other locations have been rece ntly reported. Methods. The study included 32 patients (20 men, 12 wom en, mean [+/-SD] age 29 +/- 15 years) with a diagnosis of permanent ju nctional reciprocating tachycardia confirmed at electrophysiologic stu dy. Seven patients had depressed left ventricular function. Radiofrequ ency energy was applied at the site of the earliest retrograde atrial activation during tachycardia. Results. There were 33 accessory pathwa ys. The site of the earliest retrograde atrial activation was posteros eptal in 25 patients (76%), midseptal in 4 (12%), right posterior in 1 (3%), right lateral in 1 (3%), left posterior in 1 (3%) and left late ral in 1 (3%). Thirty pathways were ablated with a right approach; in 11 patients with posteroseptal pathway the ablation was performed thro ugh the coronary sinus. Three pathways were ablated with a left approa ch. Positive retrograde P wave in lead I suggested that ablation could be performed from the right side; if negative, it did not exclude abl ation from this approach. All the accessory pathways were successfully ablated, with a median of 3 and a mean of 5.6 +/- 5 radiofrequency ap plications of 70 +/- 26 s in duration. In two patients,vith the access ory pathway in the midseptal zone, a transient second- and third-degre e atrioventricular block, respectively, was observed after ablation. A t a mean follow-up of 18 +/- 12 months, 31 patients (97%) are asymptom atic without antiarrhythmic therapy (95% confidence interval [CI] 84% to 99%). Recurrences were observed in four patients (13%) (95% CI 4% t o 29%), three of whom had the accessory pathway ablated successfully a t a second session. All patients with depressed left ventricular funct ion showed a marked improvement after successful ablation. Conclusions . In our experience, most of the patients with permanent junctional re ciprocating tachycardia had posteroseptal pathways; all these pathways were ablated from the right side. P wave configuration may be helpful in suggesting the approach to the site of ablation. Catheter ablation using radiofrequency energy is an effective therapy for permanent jun ctional reciprocating tachycardia.