title: Epicardial catheter ablation for ventricular tachycardia in heparinized patients.
abstract: OBJECTIVE
  In patients undergoing epicardial catheter ablation of ventricular tachycardia (VT), current guidelines recommend obtaining pericardial access prior to heparinization to minimize bleeding complications. Consequently, access is obtained before endocardial mapping (leading to unnecessary punctures) or during an additional procedure. We present our experience of obtaining pericardial access during the index procedure in heparinized patients.
  
  
  RESULTS
  Patients undergoing catheter ablation of VT in whom pericardial access was performed after heparinization were included. Clinical and procedural data and complications were recorded. Electrocardiograms (ECGs) were analysed for published criteria suggesting an epicardial ablation target and compared with patients (matched for substrate) undergoing successful endocardial ablation. Seventeen patients (13 males, age 58 ± 16 years, 8 (47%) ischaemic) were evaluated. Pericardial access was achieved in 16 (94%), including 2 patients with prior epicardial ablation. The mean activated clotting time was 273 ± 36 s. No bleeding complications occurred. In three patients, inadvertent puncture of the right ventricle caused no adverse consequences. An epicardial ablation target was found in nine of which three (33%) had ECG criteria, suggesting an epicardial circuit. In comparison 5 of 17 patients undergoing successful endocardial ablation had at least one ECG criterion suggesting an epicardial ablation target.
  
  
  CONCLUSIONS
  Obtaining pericardial access for epicardial catheter ablation for VT appears to be safe in heparinized patients. Electrocardiogram criteria suggesting an epicardial ablation target lack the sensitivity and specificity accurately to predict which patients might need epicardial ablation. Performing pericardial access in heparinized patients therefore may reduce unnecessary punctures and reduce the number of additional procedures in some patients.
authors.affiliation: Department of Electrophysiology,  St Bartholomew's Hospital, West Smithfield, London EC1A 7BE,  UK.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Page
authors.forename: Edward R
authors.initials: ER
authors.lastname: Duncan
authors.forename: Glyn
authors.initials: G
authors.lastname: Thomas
authors.forename: Matt R
authors.initials: MR
authors.lastname: Ginks
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Earley
authors.forename: Simon C
authors.initials: SC
authors.lastname: Sporton
authors.forename: Mehul
authors.initials: M
authors.lastname: Dhinoja
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Schilling
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000008:administration & dosage* / Q000009:adverse effects; D002309:Cardiology / Q000706:statistics & numerical data; D017115:Catheter Ablation / Q000379:methods*; D056149:Epicardial Mapping; D005240:Feasibility Studies; D005260:Female; D006470:Hemorrhage / Q000139:chemically induced / Q000517:prevention & control*; D006493:Heparin / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D010496:Pericardium / Q000601:surgery; D017410:Practice Guidelines as Topic; D017180:Tachycardia, Ventricular / Q000601:surgery*; D016896:Treatment Outcome
chemical_list: D000925:Anticoagulants; D006493:Heparin