title: Intra-coronary guidewire mapping-a novel technique to guide ablation of human ventricular tachycardia.
abstract: OBJECTIVE
  Endocardial catheter ablation of ventricular tachycardia (VT) may fail if originating from epicardial or intramural locations. We hypothesized that mapping could be achieved using an angioplasty guidewire in the coronary circulation, to guide trans-coronary ablation.
  
  
  RESULTS
  Six patients (2 male), 64 +/- 14 years and previously unsuccessful endocardial VT ablation were studied. Using ECG and existing endocardial mapping data, a coronary artery supplying the predicted VT origin was selected. A 0.014-in angioplasty guidewire was advanced into branches of the artery and connected to an amplifier to record unipolar signals against an indifferent electrode within the inferior vena cava. An uninflated angioplasty balloon was advanced over the wire such that only the distal 5 mm was used for mapping. One VT per patient was mapped (CL 348 +/- 102.1 ms). Diastolic potentials were recorded from all (77.7 +/- 43.8 ms pre-QRS onset) and concealed entrainment demonstrated in 3. Pacemapping during sinus rhythm was used in the remainder due to failure of entrainment (n = 2) or degeneration to VF (n = 1). Following branch identification, cold saline injection causing VT termination was used for further confirmation. Five VTs were ablated using intra-coronary ethanol injection via the central lumen of the inflated over the wire balloon. The other was ablated using radiofrequency energy in a coronary vein adjacent to the target artery, which was too small for an angioplasty balloon. No complications or recurrence of ablated VT was seen over 19 +/- 17 months of follow up.
  
  
  CONCLUSIONS
  Intracoronary guidewire mapping is a novel method of electrophysiological epicardial mapping to help guide trans-coronary VT ablation.
authors.affiliation: St. Mary's Hospital and Imperial College of Medicine, London, UK.
authors.forename: Oliver R
authors.initials: OR
authors.lastname: Segal
authors.forename: Tom
authors.initials: T
authors.lastname: Wong
authors.forename: Anthony W C
authors.initials: AW
authors.lastname: Chow
authors.forename: Julian W E
authors.initials: JW
authors.lastname: Jarman
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schilling
authors.forename: Vias
authors.initials: V
authors.lastname: Markides
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Peters
authors.forename: D
authors.initials: D
authors.lastname: Wyn Davies
mesh_terms: D000328:Adult; D000368:Aged; D015906:Angioplasty, Balloon, Coronary / Q000295:instrumentation*; D018780:Body Surface Potential Mapping; D002404:Catheterization; D003331:Coronary Vessels; D022062:Electrophysiologic Techniques, Cardiac; D000431:Ethanol / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017180:Tachycardia, Ventricular / Q000628:therapy*
chemical_list: D000431:Ethanol