Radiofrequency Ablation Therapy in Three Patients with Paroxysmal Atrial Tachycardia

Radiofrequency ablation therapy was performed in three patients with paroxysmal atrial tachycardia. There were two females and one male, aged 80, 63, and 75 years, respectiveiy. All three patients had induction of sustained atrial tachycardia. The tachycardia could be terminated by overdrive atrial pacing or atrial premature stimulation; it could also be terminated by intravenous bolus of adenosine triphosphate. In all three patients, there was no fragmented atrial electrograms recorded within the right atrium, and there was no ventriculo-atrial conduction during ventricular pacing. Tiie earliest atrial activation during tachycardia in these three patients was registered, respectively, at a site slightly posterior and inferior to the His-bundle recording site, at the anterior-superior border of Koch's triangle slightly posterior to the His-bundle recording site, and at the mid-lateral aspect of the right atrium over the crista terminalis at the junction of right atrial appendage and sinus venarum. Radiofrequency current was deiivered to the site of the earliest atrial activation during tachycardia through a 4-mm tip electrode catheter. It resulted in termination of tachycardia and ablation of the tachycardia focus. FoIIow-up observation over a period of 16, 15, and 4 months, respectively, in these three patients showed no recurrence of tachycardia. A repeat eiectrophysiological study was performed 52 and 63 days after ablation in two patients and revealed no induction of atrial tachycardia.