title: Mapping Strategy Associated with QRS Morphology for Catheter Ablation in Patients with Idiopathic Ventricular Outflow Tract Tachyarrhythmia.
abstract: BACKGROUND
  In catheter ablation of idiopathic ventricular arrhythmia (VA), it is still unclear whether pace mapping or activation mapping is more useful for successful catheter ablation. The depth of origin in the ventricular wall especially affects the success rate of endocardial-approached catheter ablation. Thus, we examined the relationship between these tactics and QRS morphology.
  
  
  METHODS
  We evaluated the relationship among pace mapping score, activation time, and peak deflection index (PDI) in 28 patients, with a total of 30 origins, who underwent successful catheter ablation of idiopathic VA.
  
  
  RESULTS
  All origins were located in the ventricular outflow tract area, including three in the left coronary cusp (LCC). PDI, activation time, and pace mapping score at successful ablation sites were 0.60 ± 0.08, 26.3 ± 9.9 ms, and 19.1 ± 4.6, respectively. The pace mapping score inversely correlated with the PDI (R = -0.540, P = 0.0017), but the activation time did not correlate with the PDI. When excluding the three VAs originating from the LCC, in which perfect pace mapping was obtained from epicardial sites despite high PDI, this correlation coefficient became more intensive (R = -0.734, P < 0.0001).
  
  
  CONCLUSIONS
  Our study suggests that pace mapping with an endocardial approach could not reproduce the precise QRS morphology for VA originating from the intramural site of the ventricular wall. With such origins, we should rely on activation mapping to detect the optimal ablation site.
authors.affiliation: Department of Cardiology and Hematology, Fukushima Medical University, Fukushima, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kaneshiro
authors.affiliation: Department of Cardiology and Hematology, Fukushima Medical University, Fukushima, Japan.|Department of Arrhythmia and Cardiac Pacing, Fukushima Medical University, Fukushima, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of Cardiology and Hematology, Fukushima Medical University, Fukushima, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Nodera
authors.affiliation: Department of Cardiology and Hematology, Fukushima Medical University, Fukushima, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Department of Cardiology and Hematology, Fukushima Medical University, Fukushima, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kamioka
authors.affiliation: Department of Cardiology and Hematology, Fukushima Medical University, Fukushima, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kamiyama
authors.affiliation: Department of Cardiology and Hematology, Fukushima Medical University, Fukushima, Japan.|Department of Arrhythmia and Cardiac Pacing, Fukushima Medical University, Fukushima, Japan.
authors.forename: Yasuchika
authors.initials: Y
authors.lastname: Takeishi
mesh_terms: D002304:Cardiac Pacing, Artificial / Q000379:methods; D017115:Catheter Ablation / Q000379:methods*; D056149:Epicardial Mapping / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging* / Q000601:surgery*; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging* / Q000601:surgery*
keywords: QRS morphology; activation mapping; catheter ablation; idiopathic ventricular tachyarrhythmia; pace mapping