title: Coronary artery reperfusion for ST elevation myocardial infarction is associated with shorter cycle length ventricular tachycardia and fewer spontaneous arrhythmias.
abstract: OBJECTIVE
  Ventricular tachycardia (VT) induction at electrophysiological (EP) study early after ST elevation myocardial infarction (STEMI) has been a predictor of spontaneous ventricular arrhythmia. Reperfusion therapy for STEMI may have resulted in altered VT character. We attempted to determine differences in VT cycle length (CL) and VT recurrence rates, in patients who received early and late reperfusion treatment for STEMI.
  
  
  RESULTS
  Of 180 consecutive patients with left ventricular ejection fraction < 40%, 77 patients had positive EP studies. Forty-nine patients receiving early reperfusion treatment (group 1, n = 49) were compared with 28 patients who received late reperfusion (group 2; n = 28). Seventy-five patients had defibrillators implanted for primary prevention of sudden death. Patients were followed for up to 6 years to assess long-term rates of spontaneous ventricular tachyarrhythmia. Patients who received early reperfusion demonstrated shorter CL inducible VT (231 ± 43 ms vs. 252 ± 56 ms; P = 0.016). They also had fewer spontaneous arrhythmias (adjusted hazard ratio of 2.94, 95% confidence interval: 1.07-8.13; P = 0.03) with shorter CL spontaneous VT (266 ± 54 ms vs. 320 ± 80 ms; P = 0.02) at 53 ± 33 months. Ventricular tachycardia CL was the only independent predictor of spontaneous arrhythmia or sudden cardiac death (1.22, 1.07-1.47; P = 0.016).
  
  
  CONCLUSIONS
  Patients receiving early reperfusion for STEMI had faster inducible and spontaneous VT and fewer spontaneous recurrences. This may be due to changes in the myocardial substrate as a result of early coronary artery reperfusion.
authors.affiliation: Department of Cardiology, Westmead Hospital, Westmead, Sydney, NSW 2145, Australia.
authors.forename: Chrishan J
authors.initials: CJ
authors.lastname: Nalliah
authors.affiliation: Department of Cardiology, Westmead Hospital, Westmead, Sydney, NSW 2145, Australia.
authors.forename: Sarah
authors.initials: S
authors.lastname: Zaman
authors.affiliation: Department of Cardiology, Westmead Hospital, Westmead, Sydney, NSW 2145, Australia.
authors.forename: Arun
authors.initials: A
authors.lastname: Narayan
authors.affiliation: Department of Cardiology, Westmead Hospital, Westmead, Sydney, NSW 2145, Australia.
authors.forename: Janice
authors.initials: J
authors.lastname: Sullivan
authors.affiliation: Department of Cardiology, Westmead Hospital, Westmead, Sydney, NSW 2145, Australia pramesh.kovoor@sydney.edu.au.
authors.forename: Pramesh
authors.initials: P
authors.lastname: Kovoor
mesh_terms: D000328:Adult; D000368:Aged; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control; D017147:Defibrillators, Implantable; D018572:Disease-Free Survival; D004554:Electric Countershock / Q000295:instrumentation; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D015425:Myocardial Reperfusion / Q000009:adverse effects / Q000401:mortality; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012008:Recurrence; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology / Q000517:prevention & control; D013997:Time Factors; D061665:Time-to-Treatment; D016896:Treatment Outcome
keywords: Acute myocardial infarction; Electrophysiology; ST elevation myocardial infarction; Ventricular tachycardia