title: Characteristics of ventricular tachycardia arising from the inflow region of the right ventricle.
abstract: BACKGROUND
  Ventricular tachycardia (VT) arising from the right ventricular inflow (RVI) region is uncommon. There is minimal literature on the clinical and electrocardiographic characteristics of RVI VT.
  
  
  METHODS
  A retrospective analysis of patients with RVI VT who underwent electrophysiology study between 2006 and 2011 was performed. Patients with structural heart disease (including arrhythmogenic right ventricular dysplasia) were excluded.
  
  
  RESULTS
  Seventy patients underwent an electrophysiology study for VT arising from the right ventricle during the study period. Nine patients (13%) met the inclusion criteria for RVI VT and were the subject of this analysis. The median age was 46 years (range, 14-71), and VT cycle length was 295 milliseconds (range, 279-400 milliseconds). All VTs had an left bundle-branch block morphology. An inferiorly directed QRS axis was noted in 7 (78%) of 9 patients and a left superior axis in 2 (22%) of 9 patients. A QS or rS pattern was noted in all patients in aVR and V(1). A transition from S to R wave occurred in V(3) to V(5) in all patients, with 78% of the patients transitioning in V(4) or V(5). Ablation was attempted in 8 (89%) of 9 patients and was successful in 6 (67%) of 9 patients. Ablation was limited in all unsuccessful patients due to the proximity to the His and risk of complete heart block.
  
  
  CONCLUSIONS
  Electrocardiographic findings of a left bundle-branch block with a normal QRS axis, QS or rS patterns in aVR and V(1), and late S to R transition (V(4)/V(5)) are commonly found in RVI VT. Because of the proximity to the His, ablation of RVI VT may be more challenging than that of right ventricular outflow tract VT.
authors.affiliation: Division of Pediatric Cardiology, Pediatric Arrhythmia Service, The Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY. Electronic address: ceresnak@yahoo.com.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Ceresnak
authors.affiliation: Division of Pediatric Cardiology, Pediatric Arrhythmia Service, The Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Pass
authors.affiliation: Division of Cardiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Krumerman
authors.affiliation: Division of Cardiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Soo G
authors.initials: SG
authors.lastname: Kim
authors.affiliation: Division of Pediatric Cardiology, Pediatric Arrhythmia Service, The Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY.
authors.forename: Lynn
authors.initials: L
authors.lastname: Nappo
authors.affiliation: Division of Cardiology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY.
authors.forename: John D
authors.initials: JD
authors.lastname: Fisher
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002037:Bundle-Branch Block / Q000150:complications / Q000175:diagnosis; D017115:Catheter Ablation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000150:complications / Q000503:physiopathology* / Q000601:surgery; D016278:Ventricular Function, Right; D055815:Young Adult