title: Repetitive ventricular responses induced by radiofrequency ablation for idiopathic ventricular tachycardia originating from the outflow tract of the right ventricle.
abstract: In 23 consecutive patients, radiofrequency (RF) ablation was used as treatment for idiopathic ventricular tachycardia (VT) originating from the outflow tract of the right ventricle. In this study, we focused on the repetitive ventricular response (> 5 consecutive QRS beats during RF application). The incidence and clinical implications of the repetitive ventricular response were examined through the results of endocardial mapping and RF ablation. VT origin was mapped as the earliest activation site during VT, and it was determined within 0.5 x 0.5 cm (narrow site) in 13 patients and wider than 0.5 x 0.5 cm (wide origin) in the other 10 patients. The repetitive ventricular response was induced during application of RF current in 14 of 23 patients (61%), and it was more frequently observed in VT from a wide origin (100%) than in the VT from a narrow site (31%). The QRS morphology of the repetitive ventricular response was identical to that of clinical VT. As RF application was continued and/or repeated, the RR interval of the repetitive ventricular response was gradually prolonged, the number of consecutive QRS complexes was decreased, and clinical VT was finally eliminated. The overall success rate of RF ablation was 96% (22/23 patients), and no complications were observed. In conclusion, a repetitive ventricular response was frequently observed in idiopathic right VT. The changing pattern of repetitive ventricular response, slowly and/or disappearing was consistent with successful RF ablation.
authors.affiliation: First Department of Internal Medicine, Niigata University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Chinushi
authors.forename: Y
authors.initials: Y
authors.lastname: Aizawa
authors.forename: K
authors.initials: K
authors.lastname: Ohhira
authors.forename: S
authors.initials: S
authors.lastname: Fujita
authors.forename: M
authors.initials: M
authors.lastname: Shiba
authors.forename: S
authors.initials: S
authors.lastname: Niwano
authors.forename: H
authors.initials: H
authors.lastname: Furushima
mesh_terms: D000328:Adult; D000368:Aged; D002304:Cardiac Pacing, Artificial; D017115:Catheter Ablation; D004569:Electroencephalography; D005260:Female; D006329:Heart Conduction System / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000503:physiopathology* / Q000601:surgery*; D016278:Ventricular Function, Right