title: Electrocardiographic and electrophysiologic characteristics of ventricular tachycardia originating within the pulmonary artery.
abstract: OBJECTIVE
  We investigated the electrocardiographic (ECG) and electrophysiologic characteristics of ventricular tachycardia (VT) originating within the pulmonary artery (PA).
  
  
  BACKGROUND
  Radiofrequency catheter ablation (RFCA) is routinely applied to the endocardial surface of the right ventricular outflow tract (RVOT) in patients with idiopathic VT of left bundle branch block morphology. It was recently reported that this arrhythmia may originate within the PA.
  
  
  METHODS
  Activation mapping and ECG analysis were performed in 24 patients whose VTs or ventricular premature contractions (VPCs) were successfully ablated within the PA (PA group) and in 48 patients whose VTs or VPCs were successfully ablated from the endocardial surface of the RVOT (RV-end-OT group).
  
  
  RESULTS
  R-wave amplitudes on inferior ECG leads, aVL/aVR ratio of Q-wave amplitude, and R/S ratio on lead V(2) were significantly larger in the PA group than in the RV-end-OT group. On intracardiac electrograms, atrial potentials were more frequently recorded in the PA group than in the RV-end-OT group (58% vs. 12%; p < 0.01). The amplitude of local ventricular potentials recorded during sinus rhythm within the PA was significantly lower than that recorded from the RV-end-OT (0.62 +/- 0.56 mV vs. 1.55 +/- 0.88 mV; p < 0.01).
  
  
  CONCLUSIONS
  Ventricular tachycardia originating within the PA has different electrocardiographic and electrophysiologic characteristics from that originating from the RV-end-OT. When mapping the RVOT area, the catheter may be located within the PA if a low-voltage atrial or local ventricular potential of <1-mV amplitude is recorded. Heightened attention must be paid if RFCA is required within the PA.
authors.affiliation: Cardiovascular Center, Yokosuka Kyosai General Hospital, Kanagawa, Japan. y-seki@dg7.so-net.ne.jp
authors.forename: Yukio
authors.initials: Y
authors.lastname: Sekiguchi
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Aonuma
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takahashi
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Yamauchi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hachiya
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yokoyama
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Iesaka
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Isobe
mesh_terms: D000328:Adult; D000368:Aged; D002037:Bundle-Branch Block / Q000175:diagnosis / Q000601:surgery; D017115:Catheter Ablation; D017023:Coronary Angiography; D004452:Echocardiography; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000473:pathology / Q000601:surgery; D006352:Heart Ventricles / Q000473:pathology / Q000601:surgery; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000473:pathology* / Q000601:surgery; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000601:surgery; D016896:Treatment Outcome; D014694:Ventricular Outflow Obstruction / Q000175:diagnosis / Q000601:surgery