[Electrical ablation with high frequency (radiofrequency) in patients with recurrent atrioventricular nodal reentrant tachycardia--introductory information].

In 10 patients (pts) with atrioventricular nodal reentrant tachycardia type slow/fast (AVNRT) refractory to the antiarrhythmic treatment, radiofrequency current catheter ablation was performed. Adult pts (mean age 31 years) suffered from paroxysms of AVNRT for 2 to 18 years (mean 8 years). Episodes of arrhythmia recurred from 2-3 times a week to 1 for several months during antiarrhythmic therapy. The mean rate of the tachycardia was 243/min. 3 pts had syncope and 5 fainted during the tachycardia. In 2 females mitral valve prolapse was diagnosed. Programmed stimulation of the right atrium on the basic rate 130/min revealed ERP of the slow pathway mean 238 ms and ERP of the fast one mean 346 ms. The tachycardia has been induced with right atrium stimulation--most often programmed or burst stimulation--200 and 220/min, sometimes with incremental pacing. Successful radiofrequency energy ablation was performed in all 10 pts. Average number of the impulses for one pt was 7.7 (from 1 to 18 impulses). The total average time of the ablation was 216 s. The temperature of effective ablation was average 65 centigrade. The effect of the ablation was evaluated during repeated electrophysiological study before and after intravenous injection of atropine. Ablation was considered successful when no tachycardia was induced. P-R interval did not change and no episodes of AVNRT was observed in the 1-3 months follow-up. No complications were observed during the ablation and after the procedure, especially no thromboembolism was noticed. The echocardiographic evaluation revealed no damage to the heart structure. The pts receive no antiarrhythmic treatment and they are systematically controlled.