title: Percutaneous pericardial instrumentation for endo-epicardial mapping of previously failed ablations.
abstract: BACKGROUND
  The epicardial location of an arrhythmia could be responsible for unsuccessful endocardial catheter ablation.
  
  
  RESULTS
  In 48 patients referred after prior unsuccessful endocardial ablation, we considered percutaneous, subxiphoid instrumentation of the pericardial space for mapping and ablation. Thirty patients had ventricular tachycardia (VT), 6 patients had a right- and 4 had a left-sided accessory pathway (AP), 4 patients had inappropriate sinus tachycardia, and 4 patients had atrial arrhythmias. Of the 30 VTs, 24 (6 with ischemic cardiomyopathy, 3 with idiopathic cardiomyopathy, and 15 with normal hearts) appeared to originate from the epicardium. Seventeen (71%) of these 24 VTs were successfully ablated with epicardial lesions. The other 7 VTs had early epicardial sites that were inaccessible, predominantly because of interference from the left atrial appendage. Six of these were successfully ablated from the left coronary cusp. In 5 of the 10 patients with an AP, the earliest activation was recorded epicardially. Three of these were right atrial appendage-to-right ventricle APs, and epicardial ablation was successful. No significant complications were observed.
  
  
  CONCLUSIONS
  Failure of endocardial ablation could reflect the presence of an epicardial arrhythmia substrate. Epicardial instrumentation and ablation appeared feasible and safe and provided an alternative strategy for the treatment of patients with a variety of arrhythmias. This was particularly true for VT, including patients without structural heart disease.
authors.affiliation: Department of Cardiovascular Medicine/F15, Section of Electrophysiology and Pacing, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, Ohio 44195, USA. Schweir@ccf.org
authors.forename: Robert A
authors.initials: RA
authors.lastname: Schweikert
authors.forename: Walid I
authors.initials: WI
authors.lastname: Saliba
authors.forename: Gery
authors.initials: G
authors.lastname: Tomassoni
authors.forename: Nassir F
authors.initials: NF
authors.lastname: Marrouche
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Cole
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Dresing
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Tchou
authors.forename: Dianna
authors.initials: D
authors.lastname: Bash
authors.forename: Salwa
authors.initials: S
authors.lastname: Beheiry
authors.forename: Cathy
authors.initials: C
authors.lastname: Lam
authors.forename: Logan
authors.initials: L
authors.lastname: Kanagaratnam
authors.forename: Andrea
authors.initials: A
authors.lastname: Natale
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000601:surgery*; D001281:Atrial Fibrillation / Q000601:surgery; D018780:Body Surface Potential Mapping / Q000295:instrumentation*; D017115:Catheter Ablation; D004699:Endocardium; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010496:Pericardium; D013616:Tachycardia, Sinus / Q000601:surgery; D017180:Tachycardia, Ventricular / Q000601:surgery; D017211:Treatment Failure; D016896:Treatment Outcome