Case PresentationA 30-year-old man with antidromic AVRT had received transcatheter ablation of left posterolateral accessory pathway twice before, but it was recurred again. He was referred to our laboratory for further ablation. At our laboratory, antegrade accessory pathway could be manifested during atrial extrastimuli at 500/250 msec with the initiation of wide QRS complex tachycardia. Trans-aortic approach was hard to achieve the insertion site of the accessory pathway. For avoiding trauma of accessory pathway, antegrade approach with 3D NavX endocardial mapping system was applied. Far field ventricular activation mapping after left atrial geometry construction was done. The earliest ventricular activation site was mapped inside left atrium during antidromic AVRT. AVRT was terminated immediately after radiofrequency application at the earliest ventricular activation site. Tachycardia was no longer inducible after procedure, and the patient was followed in outpatient clinics without recurrence of SVT. Discussion The recurrence rate of SVT was higher in patients with mechanical trauma than in those without (33.3% vs 3.5%). In face of such difficulty, 3D-endocardial mapping system may help to localize the target site. The earliest ventricular activation site was detected by NavX endocardial mapping system, and radiofrequency ablation was completed successfully with the elimination of accessory atrioventricular connection without recurrence.
- accessory pathway
- electro-anatomic mapping system