[Therapy of AV nodal reentry tachycardia with catheter ablation of the fast retrograde pathway].

AV-nodal reentrant tachycardia (AVNRT) is a common cause of recurrent supraventricular tachycardia. Currently, catheter ablation of either slow or fast pathway are nonpharmacologic options for the treatment of patients with AVNRT. Radiofrequency (RF) catheter ablation of the fast pathway was attempted in 35 patients (aged 46.7 +/- 15 years; 12 m, 23 f) with recurrent AVNRT. RF energy (25-50 watt, 30-90 s) was delivered to the anterior right atrial septum. The catheter was placed posterior to the largest His bundle deflection. AV conduction was monitored during continuous pacing of the high right atrium while the RF current was applied. RF-ablation was acutely successful using a mean of 6.5 +/- 6.2 impulses in 31 patients. Late spontaneous block of the slow pathway occurred in one patient (pat. 17) with an unsuccessful initial attempt of fast pathway ablation. PQ and AH interval increased significantly after the ablation procedure (PQ: from 149 +/- 27 to 208 +/- 34 ms, AH: from 76 +/- 22 to 131 +/- 38 ms; p value: < 0.0001). Acute interruption of retrograde VA conduction was the result in 23 patients. Six patients (17%) had a recurrence of AVNRT during a follow-up period of 11.9 +/- 7.5 months. Five of 6 patients underwent a second successful procedure. Complete AV block occurred in 3 of the first 10 consecutive patients and in none of the subsequent 25 patients (overall incidence: 8.6%). Thus, RF ablation of the fast retrograde pathway is an effective method for the curative treatment of AVNRT.(ABSTRACT TRUNCATED AT 250 WORDS)