title: Idiopathic ventricular arrhythmia arising from the mitral annulus: a distinct subgroup of idiopathic ventricular arrhythmias.
abstract: OBJECTIVE
  We sought to clarify the prevalence and characteristics of idiopathic ventricular tachycardia or premature ventricular contraction originating from the mitral annulus (MAVT/PVC).
  
  
  BACKGROUND
  Recent case reports have presented patients with MAVT/PVC.
  
  
  METHODS
  Electrocardiographic (ECG) characteristics and the results of electrophysiologic investigation and radiofrequency catheter ablation (RFCA) were analyzed in 352 patients with symptomatic idiopathic ventricular tachycardia (IVT)/premature ventricular contraction (PVC).
  
  
  RESULTS
  Nineteen cases of IVT/PVC (5%) represented MAVT/PVC. Of these, 11 (58%) originated from the anterolateral portion of the mitral annulus (AL-MAVT/PVC), and 2 (11%) arose from the posterior portion (Pos-MAVT/PVC). The remaining six cases of MAVT/PVC (31%) had posteroseptal origin (PS-MAVT/PVC). In all patients, an S-wave was present in lead V(6). The QRS polarity in inferior leads and leads I and aVL was useful for differentiating AL-MAVT/PVC from Pos-MAVT/PVC or PS-MAVT/PVC. The Pos-MAVT/PVC had an Rs pattern in lead I and an R pattern in lead V(1), whereas PS-MAVT/PVC invariably had an R pattern in lead I and a negative QRS component in lead V(1). The AL-MAVT/PVC and Pos-MAVT/PVC showed a longer QRS duration than the PS-MAVT/PVC (p < 0.001), and all had late-phase "notching" of the QRS complex in inferior leads. In all patients, RFCA eliminated MAVT/PVC, with no recurrences during follow-up for 21 +/- 15 months.
  
  
  CONCLUSIONS
  Mitral annular VT/PVC is a rare but distinct subgroup of IVT/PVC. MAVT/PVC origin could be determined by ECG analysis. The AL and PS sites of the MA were preferential.
authors.affiliation: Division of Cardiology, Gunma Prefectural Cardiovascular Center, Maebashi, Gunma, Japan. tada.h@cvc.pref.gunma.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tada
authors.forename: Sachiko
authors.initials: S
authors.lastname: Ito
authors.forename: Shigeto
authors.initials: S
authors.lastname: Naito
authors.forename: Kenji
authors.initials: K
authors.lastname: Kurosaki
authors.forename: Shoichi
authors.initials: S
authors.lastname: Kubota
authors.forename: Aiko
authors.initials: A
authors.lastname: Sugiyasu
authors.forename: Taketsugu
authors.initials: T
authors.lastname: Tsuchiya
authors.forename: Kohei
authors.initials: K
authors.lastname: Miyaji
authors.forename: Minoru
authors.initials: M
authors.lastname: Yamada
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Kutsumi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Oshima
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nogami
authors.forename: Koichi
authors.initials: K
authors.lastname: Taniguchi
mesh_terms: D000328:Adult; D000368:Aged; D002304:Cardiac Pacing, Artificial; D017115:Catheter Ablation; D015716:Electrocardiography, Ambulatory; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000473:pathology / Q000601:surgery; D006349:Heart Valve Diseases / Q000453:epidemiology / Q000209:etiology* / Q000601:surgery; D006352:Heart Ventricles / Q000473:pathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000473:pathology* / Q000601:surgery; D015995:Prevalence; D017180:Tachycardia, Ventricular / Q000453:epidemiology / Q000209:etiology* / Q000601:surgery; D016896:Treatment Outcome; D018879:Ventricular Premature Complexes / Q000453:epidemiology / Q000209:etiology* / Q000601:surgery