title: Significance of inducible very fast ventricular tachycardia (cycle length 200-230 ms) after early reperfusion for ST-segment-elevation myocardial infarction.
abstract: BACKGROUND
  Electrophysiological study (EPS) after myocardial infarction may have a role in identifying patients at risk of sudden cardiac death. It has been shown previously that inducible very fast ventricular tachycardia (VT; cycle length [CL], 200-230 ms) is predictive of arrhythmia recurrence; however, its significance early after reperfusion in ST-segment-elevation myocardial infarction is unknown.
  
  
  RESULTS
  Consecutive patients with ST-segment-elevation myocardial infarction treated with primary percutaneous coronary intervention with a left ventricular ejection fraction ≤40% underwent early EPS with an implantable-cardioverter defibrillator implanted for inducible VT, but not for a negative EPS. The end point was the cumulative incidence of death or first arrhythmic event (defined as resuscitated cardiac arrest or spontaneous ventricular tachyarrhythmia). A total of 1721 patients with ST-segment-elevation myocardial infarction underwent early left ventricular ejection fraction assessment (median, 4 days after myocardial infarction) with a left ventricular ejection fraction≤40% in 24%. EPS was performed in 290 eligible patients with no arrhythmia or ventricular fibrillation/flutter (CL<200 ms) induced in 203 patients (EPS negative, group 1), monomorphic VT induced in 87 patients, consisting of very fast VT in 67% (group 2; n=58), and standard VT (CL>230 ms) in 33% (group 3; n=29). Kaplan-Meier 4-year cumulative incidence of death or arrhythmia was 8.2±2.3%, 33.1±7.1%, and 37.0±10.2% in groups 1, 2, and 3, respectively (P<0.001).
  
  
  CONCLUSIONS
  The majority of inducible VT in patients who have been reperfused early after ST-segment-elevation myocardial infarction is very fast VT (CL, 200-230 ms). This very fast VT incurs at least a similar risk of arrhythmia or death as inducible standard VT (CL>230 ms) and a significantly higher risk than patients with a negative EPS.
authors.affiliation: Department of Cardiology, Westmead Hospital, Sydney, Australia.
authors.forename: Sarah
authors.initials: S
authors.lastname: Zaman
authors.forename: Saurabh
authors.initials: S
authors.lastname: Kumar
authors.forename: Janice
authors.initials: J
authors.lastname: Sullivan
authors.forename: Arun
authors.initials: A
authors.lastname: Narayan
authors.forename: Aravinda
authors.initials: A
authors.lastname: Thiagalingam
authors.forename: David L
authors.initials: DL
authors.lastname: Ross
authors.forename: Pramesh
authors.initials: P
authors.lastname: Kovoor
mesh_terms: D017147:Defibrillators, Implantable; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology* / Q000628:therapy*; D062645:Percutaneous Coronary Intervention; D011237:Predictive Value of Tests; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000503:physiopathology; D016896:Treatment Outcome
keywords: arrhythmias, cardiac; cardioverter-defibrillators, implantable; death, sudden, cardiac; electrophysiology; myocardial infarction; tachycardia, ventricular