title: A practical criterion for the rapid detection of single-loop and double-loop reentry tachycardias.
abstract: BACKGROUND
  Entrainment criteria for the diagnosis of reentrant atrial tachycardia can be difficult to apply and cannot detect double-loop reentry. We sought to develop and clinically test a new criterion for the diagnosis of single- and double-loop reentry.
  
  
  RESULTS
  (1) Proposed criterion: after sequential overdrive pacing at 2 different locations and assessing the first ensuing beats of tachycardia, the difference in activation time recorded between 2 appropriate stationary positions changes by 1 or 2 tachycardia cycle lengths; a change of 2 tachycardia cycle lengths usually indicates double-loop reentry rather than only a single-loop. (2) Clinical testing: multiple overdrive pacing maneuvers were undertaken and analyzed in 5 patients with common flutter (single-loop reentry). In total, 23 pairs of overdrive pacing maneuvers were performed using electrodes in the coronary sinus and a distribution of positions in the right atrium. In 22/23 pairs of maneuvers, the change in Activation Difference was within 2.6 ± 12.4 milliseconds of the tachycardia cycle length, confirming single loop reentry. For double-loop reentry, the literature was reviewed and 3 cases of double-loop reentry were identified with sufficient data. In all of these cases, double-loop reentry was detected and also the zone containing the common isthmus was identified.
  
  
  CONCLUSIONS
  The proposed criterion can diagnose single- and double-loop reentry atrial tachycardia using intracardiac recordings from any pair of well separated positions. The criterion does not require precise electrode placement or extensive activation mapping.
authors.affiliation: King's College London, UK. nick@foxlinton.org
authors.forename: Nick W F
authors.initials: NW
authors.lastname: Linton
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Wilton
authors.forename: Daniel
authors.initials: D
authors.lastname: Scherr
authors.forename: Ashok J
authors.initials: AJ
authors.lastname: Shah
authors.forename: Nicolas
authors.initials: N
authors.lastname: Derval
authors.forename: Frederic
authors.initials: F
authors.lastname: Sacher
authors.forename: Matthew
authors.initials: M
authors.lastname: Wright
authors.forename: Mélèze
authors.initials: M
authors.lastname: Hocini
authors.forename: Mark D
authors.initials: MD
authors.lastname: O'Neill
authors.forename: Michel
authors.initials: M
authors.lastname: Haïssaguerre
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
mesh_terms: D001282:Atrial Flutter / Q000503:physiopathology; D004562:Electrocardiography; D006801:Humans; D008433:Mathematics; D008962:Models, Theoretical; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000175:diagnosis* / Q000503:physiopathology