title: Reentrant ventricular tachycardia originating from the periaortic region in the absence of overt structural heart disease.
abstract: BACKGROUND
  In the absence of overt structural heart disease, most left ventricular outflow tract ventricular tachycardias (VTs) have a focal origin and are benign. We hypothesized that multiple morphologies (MMs) of inducible left ventricular outflow tract VT may indicate a scar-related VT that can mimic idiopathic VT.
  
  
  RESULTS
  Of 54 consecutive patients referred for ablation of sustained outflow tract VT without overt structural heart disease, 24 had left ventricular outflow tract VT, 10 had MM VT, and 14 had a single VT (SM). The MM group were older (70.3±4.3 versus 53.9±15.9 years; P=0.004), had more hypertension (100% versus 29%; P=0.0006), and had longer PR intervals and QRS durations compared with the SM group. In contrast to the SM group, the MM group VTs had features consistent with reentry, including induction by programmed stimulation without isoproterenol, entrainment in some, and abnormal electrograms in the periaortic area. Periaortic region voltages suggested scar in the MM group, but not in the SM group. MRI in 2 MM patients was consistent with scar, but not in 10 SM patients. Longer radiofrequency applications were required in the MM group than in the SM group. At a median follow-up of 9.7 (3.0-32.0) months, recurrences tended to be more frequent in the MM group than in the SM group (70% versus 22%; P=0.07).
  
  
  CONCLUSIONS
  VTs from small regions of periaortic scar can mimic idiopathic VT but are suggested by multiple VT morphologies and are more difficult to ablate. Whether these patients are at greater risk, as feared for other scar-related VTs, warrants further study.
authors.affiliation: Arrhythmia Unit, Cardiovascular Division, Brigham and Women's Hospital, Boston, MA.
authors.forename: Koichi
authors.initials: K
authors.lastname: Nagashima
authors.forename: Usha B
authors.initials: UB
authors.lastname: Tedrow
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Koplan
authors.forename: Gregory F
authors.initials: GF
authors.lastname: Michaud
authors.forename: Roy M
authors.initials: RM
authors.lastname: John
authors.forename: Laurence M
authors.initials: LM
authors.lastname: Epstein
authors.forename: Michifumi
authors.initials: M
authors.lastname: Tokuda
authors.forename: Keiichi
authors.initials: K
authors.lastname: Inada
authors.forename: Tobias R
authors.initials: TR
authors.lastname: Reichlin
authors.forename: Justin P
authors.initials: JP
authors.lastname: Ng
authors.forename: Chirag R
authors.initials: CR
authors.lastname: Barbhaiya
authors.forename: Eyal
authors.initials: E
authors.lastname: Nof
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Tadros
authors.forename: William G
authors.initials: WG
authors.lastname: Stevenson
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D002304:Cardiac Pacing, Artificial; D017115:Catheter Ablation; D002921:Cicatrix / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D054139:Tachycardia, Reciprocating / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome; D056969:Voltage-Sensitive Dye Imaging
keywords: catheter ablation; periaortic region; reentry; structural normal heart; tachycardia, ventricular