title: Electroanatomic magnetic mapping during ablation of isthmus-dependent atrial flutter.
abstract: BACKGROUND
  Although recent studies have demonstrated that the endpoint of isthmus conduction block is superior to that of termination and subsequent inability to induce atrial flutter (AFl), the optimal method for determining isthmus conduction block has not been determined. Electroanatomic magnetic mapping during coronary sinus (CS) pacing may provide a reliable endpoint for AFl ablation.
  
  
  RESULTS
  Catheter mapping and ablation was performed in 42 patients with isthmus-dependent AFl. The patients were divided into two groups, based on procedural endpoint: Group I (28 patients) - isthmus conduction block was determined based on multipolar catheter recordings and electroanatomic mapping, and Group II (14 patients) - isthmus conduction block was determined by electroanatomic mapping during CS pacing alone. In Group I, ablation procedures were acutely successful in 25 of 28 patients (89 %). A 100 % concordance between the data presented by multipolar catheter recordings and electroanatomic mapping was noted in determining the presence or absence of isthmus conduction block. In Group II, ablation procedures were acutely successful in 13 of 14 patients, 13 (93 %). After a mean of 16.3+/-3.7 months follow up, there was 1 atrial flutter recurrence in the 38 patients (2.6 %) with demonstrated isthmus block at the end of the procedure.
  
  
  CONCLUSIONS
  Electroanatomic magnetic mapping during CS pacing is comparable to the multipolar catheter mapping technique for assessing isthmus conduction block as an endpoint for AFl ablation procedures.
authors.affiliation: Clinical Electrophysiology Laboratories of the Allegheny University Hospitals, MCP Division, Philadelphia, PA, USA.
authors.forename: R F
authors.initials: RF
authors.lastname: Coyne
authors.forename: M
authors.initials: M
authors.lastname: Deely
authors.forename: C D
authors.initials: CD
authors.lastname: Gottlieb
authors.forename: F E
authors.initials: FE
authors.lastname: Marchlinski
authors.forename: D J
authors.initials: DJ
authors.lastname: Callans
mesh_terms: D000328:Adult; D000368:Aged; D001282:Atrial Flutter / Q000175:diagnosis* / Q000601:surgery*; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D055590:Electromagnetic Phenomena; D004594:Electrophysiology / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006327:Heart Block / Q000175:diagnosis / Q000601:surgery; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011336:Probability; D012680:Sensitivity and Specificity; D016896:Treatment Outcome