Catheter modification of the atrioventricular junction with radiofrequency energy for control of atrioventricular nodal reentry tachycardia.

BACKGROUNDThe utility of transcatheter application of radiofrequency energy to eliminate atrioventricular nodal reentrant tachycardia (AVNRT) was investigated.METHODS AND RESULTSThirty-nine patients (mean age, 53 +/- 20 years; range 14-86 years) with medically refractory AVNRT underwent perinodal ablation with radiofrequency energy. A custom-designed 6F catheter with a large (3-mm-long) distal electrode and interelectrode pacing of 2 mm was used in the majority of cases. The catheter used for ablation was initially positioned across the tricuspid anulus to obtain the largest His bundle electrogram, then withdrawn to obtain the largest atrial:ventricular electrogram ratio, with a small His bundle electrogram (less than or equal to 100 microV). Each application of radiofrequency energy (350-550 kHz, 16.2 +/- 5.2 W) was stopped after 60 seconds or if PR prolongation or an impedance rise was noted. The endpoints of the procedure were persistent modification of atrioventricular nodal conduction (either first-d...