title: Differentiation of ventricular and supraventricular tachycardias based on the analysis of the first postpacing interval after sequential anti-tachycardia pacing in implantable cardioverter-defibrillator patients.
abstract: BACKGROUND
  Current discrimination algorithms do not completely avoid inappropriate tachycardia detection.
  
  
  OBJECTIVE
  This study analyzes the discrimination capability of the changes of the first postpacing interval (FPPI) after successive bursts of anti-tachycardia pacing (ATP) trains in implantable cardioverter-defibrillator (ICD)-recorded tachycardias.
  
  
  METHODS
  We included 50 ICD patients in this prospective study. We hypothesized that the FPPI variability (FPPIV) when comparing bursts with different numbers of beats would be shorter in ventricular tachycardias (VTs) compared with supraventricular tachycardias (SVTs). The ATP (5-10 pulses, 91% of tachycardia cycle length) was programmed for tachycardias >240 ms.
  
  
  RESULTS
  Anti-tachycardia pacing was delivered during 37 sinus tachycardias (STs) in an exercise test, 96 induced VTs in an electrophysiological study, and 198 spontaneous episodes (144 VTs and 54 SVTs). The FPPI remained stable after all ATP bursts in VT but changed continuously in SVT; when comparing bursts of 5 and 10 pulses, the FPPIV was shorter in VT (34 +/- 65 vs.138 +/- 69, P<.0001, in all T and 12 +/- 20 vs. 138 +/- 69, P<.0001, in T>or=320 ms) than in SVT. In T>or=320 ms an FPPIV<or=50 ms between bursts of 5 and 10 pulses classified correctly 100% of VTs and 90% of SVTs. Anti-tachycardia pacing terminated 66% of induced VTs, 60% of spontaneous VTs, and 20% of spontaneous SVTs and induced no VT during spontaneous or exercise induced SVT. Five induced and two spontaneous VT episodes were accelerated.
  
  
  CONCLUSIONS
  Analysis of FPPIV after ATP discriminates ICD-detected T. Successive bursts (of ATP) trains at 91% of tachycardia cycle length are safe, despite being delivered before rhythm classification.
authors.affiliation: Laboratorio de Electrofisiología, Departamento de Cardiología, Hospital General Universitario Gregorio Marañón, Madrid, Spain. arenal@secardiologia.es
authors.forename: Angel
authors.initials: A
authors.lastname: Arenal
authors.forename: Mercedes
authors.initials: M
authors.lastname: Ortiz
authors.forename: Rafael
authors.initials: R
authors.lastname: Peinado
authors.forename: Jose L
authors.initials: JL
authors.lastname: Merino
authors.forename: Aurelio
authors.initials: A
authors.lastname: Quesada
authors.forename: Felipe
authors.initials: F
authors.lastname: Atienza
authors.forename: Arcadio García
authors.initials: AG
authors.lastname: Alberola
authors.forename: Jose
authors.initials: J
authors.lastname: Ormaetxe
authors.forename: Eduardo
authors.initials: E
authors.lastname: Castellanos
authors.forename: Juan C
authors.initials: JC
authors.lastname: Rodriguez
authors.forename: Nicasio
authors.initials: N
authors.lastname: Pérez
authors.forename: Javier
authors.initials: J
authors.lastname: García
authors.forename: Luis
authors.initials: L
authors.lastname: Boluda
authors.forename: Mario
authors.initials: M
authors.lastname: del Prado
authors.forename: Antonio
authors.initials: A
authors.lastname: Artés
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D002304:Cardiac Pacing, Artificial; D017147:Defibrillators, Implantable; D003937:Diagnosis, Differential; D016002:Discriminant Analysis; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012107:Research Design; D013617:Tachycardia, Supraventricular / Q000503:physiopathology* / Q000628:therapy*; D017180:Tachycardia, Ventricular / Q000503:physiopathology* / Q000628:therapy*; D016896:Treatment Outcome