Laser catheter coagulation of atrial myocardium for ablation of atrioventricular nodal reentrant tachycardia. First clinical experience.

A new technique for ablation of atrioventricular nodal reentrant tachycardia, using catheter-directed continuous wave Nd-YAG laser light, 1064 nm, via a novel pin-electrode laser catheter, was applied in 10 patients aged 15-63 years (mean 43 years). A total of 22 laser pulses, 1-5 per patient, at 20 or 30 W, of 10-45 s (mean 27 s) were aimed at the postero-inferior aspect of the tricuspid annulus. In all patients the tachycardia was rendered non-inducible at baseline as well as during orciprenaline administration. The amplitudes of the local atrial potentials diminished from 2.0 +/- 0.5 before to 0.4 +/- 0.4 mV after ablation, atrio-His intervals increased from 73 +/- 7 to 157 +/- 36 ms. Anterograde atrioventricular nodal refractory periods (212 +/- 31 vs 238 +/- 31 ms) and Wenckebach rate (174 +/- 8 vs 167 +/- 8 beats.min-1) did not change significantly (P > 0.05). There were no complications or recurrent arrhythmias in a follow-up of 12-35 (mean 27) months. Anatomically guided laser catheter coagulation of the postero-inferior aspect of the tricuspid valve ring is a safe and effective method for the cure of patients with common atrioventricular reentrant tachycardia.