title: Intramural idiopathic ventricular arrhythmias originating in the intraventricular septum: mapping and ablation.
abstract: BACKGROUND
  Intramural septal idiopathic ventricular arrhythmias have not been described systematically.
  
  
  RESULTS
  In a consecutive group of 93 patients with idiopathic ventricular arrhythmias referred for ablation, the site of origin of ventricular arrhythmias was assessed by activation mapping and pace-mapping. In 7 of 93 patients (8%), an intramural focus in the interventricular septum was identified. All ventricular arrhythmias arising intramurally had a left bundle-branch block morphology with inferior axis. The intramural focus was effectively ablated from both sides of the septum in 4 patients and from within the septum in 1 patient. The ablation procedure of an intramural focus near the His bundle failed in 2 of 7 patients. ECG and mapping characteristics of the patients with intramural septal ventricular arrhythmias differentiated intramural arrhythmias from other sites of origin.
  
  
  CONCLUSIONS
  Idiopathic septal ventricular arrhythmias can originate from intramural foci. Activation mapping from within a perforator branch within the interventricular septum is helpful in identifying the site of origin of intramural septal arrhythmias. Ablation within the septum or from both sites of the septum may be required to eliminate the targeted arrhythmia.
authors.affiliation: Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Miki
authors.initials: M
authors.lastname: Yokokawa
authors.forename: Eric
authors.initials: E
authors.lastname: Good
authors.forename: Aman
authors.initials: A
authors.lastname: Chugh
authors.forename: Frank
authors.initials: F
authors.lastname: Pelosi
authors.forename: Thomas
authors.initials: T
authors.lastname: Crawford
authors.forename: Krit
authors.initials: K
authors.lastname: Jongnarangsin
authors.forename: Rakesh
authors.initials: R
authors.lastname: Latchamsetty
authors.forename: Hakan
authors.initials: H
authors.lastname: Oral
authors.forename: Fred
authors.initials: F
authors.lastname: Morady
authors.forename: Frank
authors.initials: F
authors.lastname: Bogun
mesh_terms: D000328:Adult; D000792:Angiography; D002037:Bundle-Branch Block / Q000503:physiopathology / Q000601:surgery; D017115:Catheter Ablation; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery*; D054088:Ventricular Septum / Q000503:physiopathology* / Q000601:surgery