CATHETER RADIOFREQUENCY RF-ABLATION OF THE SLOW PATHWAY IN ATRIOVENTRICULAR NODAL REENTRY TACHYCARDIA (AVNRT), FIRST EXPERIENCE IN IRAQ
Abstract
Backround AVNRT is the most frequent type of regular paroxysmal Supraventricular Tachycardia (SVT) .Catheter Radiofrequency Ablation (CRFA) has been recommended as first line therapy for curing AVNRT. Objective This prospective study was conducted at AL-Kadhimiya Teaching Hospital from January 2004 to July 2006 to report the 2 years experience of CRFA of the slow pathway in patients with recurrent attacks of AVNRT refractory to medical therapy treated at our Electrophysiology laboratory (EP Lab.) and assessed for success rate and recurrence rate after CRFA. Patients And Methods Fifteen patients selected after diagnosis of typical AVNRT and been considered as refractory to drug therapy when the full single or combined antiarrhythmic therapy gave poor control. AVNRT diagnosed when the superficial ECG and the EP study showed: a, regular narrow complex tachycardia. b, no p wave or short RP long PR .c, VA interval < 55 msc. d, dual AVN conduction and AH interval jump. CRFA done with the use of a standard EPS with three diagnostic catheters and one RF Ablation catheter . AVNRT induced either spontaneously or by programmed atrial stimulation . Ablation done during tachycardia in 11 patients and during sinus rhythm in four . Slow pathway ablation done using a combined electrophysiological and anatomical approach The primary endpoint of CRFA was termination and or non-inducibility of AVNRT. RESULTS: Acute success was achieved in 15 patients (100%) . The total procedure time ranged from 30 minutes to one hour .The average fluoroscopy time was 10.5-+ 4.5 minutes .The patients were followed up for a mean of 15+- 3 months during which there was only one case of recurrence cured by a second CRFA . Complete heart block is the only complication and seen in one patient who needed permanent pacemaker implantation. Conclusion CRFA of the slow pathway is highly effective in the treatment of AVNRT . The technique has high initial success rate and low complication rate. The recurrence rate is low. CRFA should be considered as first line therapy even in drug responsive patients with AVNRT.References
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