Catheter Ablation Of Idiopathic Ventricular Tachycardia Research Articles

Catheter ablation of idiopathic left and right ventricular tachycardias in the pediatric population using noncontact mapping

Idiopathic ventricular tachycardia (VT) in children with a structurally normal heart can cause significant morbidity, and although rare, mortality. Conventional activation and pace mapping may be limited by nonsustained tachycardia or unstable hemodynamics. The aim of this study was to assess feasibility of catheter ablation of idiopathic VT in the pediatric population guided by noncontact mapping. Twenty consecutive pediatric patients with idiopathic VT underwent electrophysiologic study with the intention to use the noncontact mapping system EnSite 3000 (EnSite Array, St. Jude Medical Inc., Minneapolis, Minnesota). The multielectrode balloon array was introduced into the left or right ventricle, respectively, and tachycardia was analyzed using color-coded isopotential maps as well as reconstructed unipolar electrograms on the virtual geometry. The region of origin was identified in all of them, and the site of earliest activation with a QS pattern of the unipolar electrograms was guided for sites of ablation. Idiopathic VT originated from the right ventricular outflow tract in 6 patients, from the left ventricle in 8, and from the aortic sinus cusp in 6 in this cohort with a median age of 14.4 (range: 4.8 to 20.9) years. Ablation was attempted in 18 of 20 children, and was acutely successful in 17 of these 18 (94%). During a mean follow-up of 2.3 +/- 1.7 years, VT recurred in 3, 2 of them have been treated with a second procedure, resulting in an overall intermediate-term success in 16 of 18 (89%) children with idiopathic VT. Noncontact mapping can safely and effectively be used to map and guide catheter ablation of the tachycardia substrate of idiopathic VT in pediatric patients.

Relation between efficacy of radiofrequency catheter ablation and site of origin of idiopathic ventricular tachycardia

The results of radiofrequency catheter ablation of ventricular tachycardia (VT) in patients without structural heart disease are reported. Particular attention was focused on the relation between efficacy and the site of origin of the VT. Eighteen consecutive patients (5 women and 13 men; mean age 41 ± 13 years) with idiopathic VT underwent catheter ablation using radiofrequency energy. Sites for radiofrequency energy delivery were selected on the basis of pace mapping. A follow-up electrophysiologic test was performed 1 to 3 months after the ablation procedure. Twenty VTs were induced. Radiofrequency catheter ablation was successful in eliminating all 10 VTs originating from the right ventricular outflow tract, and 5 of 10 from other sites in the left or right ventricle. There were no complications. The duration of ablation sessions was shorter, the frequency of identifying a site resulting in an identical pace map was higher, and the efficacy of catheter ablation was greater for VTs originating from the right ventricular outflow tract than for those from other locations. The results of this study demonstrate that radiofrequency catheter ablation of idiopathic VT is safe and effective. The efficacy of the procedure is dependent on the site of origin of the VT, with the efficacy being greater for VTs originating from the outflow tract of the right ventricle than for those from other locations.