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 tachy cardia, using catheter-directed continuous wave Nd-YAG laser light, 10 64 nm, via a novel pin-electrode laser catheter, was applied in 10 pat ients 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 poten tials diminished from 2.0 +/- 0.5 before to 0.4 +/- 0.4 mV after ablat ion, atrio-His intervals increased from 73 +/- 7 to 157 +/- 36 ms. Ant erograde 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. Anatom ically guided laser catheter coagulation of the postero-inferior aspec t of the tricuspid valve ring is a safe and effective method for the c ure of patients with common atrioventricular reentrant tachycardia.