title: Early reperfusion therapy affects inducibility, cycle length, and occurrence of ventricular tachycardia late after myocardial infarction.
abstract: BACKGROUND
  This study aimed to evaluate the impact of early reperfusion during acute myocardial infarction (MI) on ventricular tachycardia (Vt) inducibility, inducible Vt cycle length (CL), and occurrence of spontaneous Vt late after MI.
  
  
  RESULTS
  Five hundred six patients (440 men; age, 63±11 years) with prior MI who underwent electrophysiology study before implantation of an implantable cardioverter-defibrillator for primary or secondary prevention were assessed. Patients were classified according to the reperfusion strategy (reperfusion: thrombolysis, n=44, or percutaneous coronary intervention, n=65, versus no reperfusion, n=397) during acute MI. Monomorphic sustained Vt was inducible in 351 (69%) patients. Inducibility in reperfused and nonreperfused patients was similar in primary prevention patients (56% versus 58%) but significantly higher for nonreperfused patients in secondary prevention patients (56% versus 79%, P=0.001). Induced VTCL was shorter (247±40 versus 287±63, P<0.001) and very fast Vt (CL ≤250 ms) was more often induced in reperfused patients (71% versus 47%, P=0.001). In primary prevention patients, nonreperfusion was associated with a doubled risk for first spontaneous Vt during follow-up.
  
  
  CONCLUSIONS
  There are important differences in Vt inducibility, induced VTCL, and occurrence of spontaneous Vt in the chronic infarct healing phase between patients with and those without successful reperfusion during acute MI. These findings suggest differences in the chronic arrhythmogenic substrate.
authors.affiliation: Department of Cardiology, Leiden University Medical Center, The Netherlands.
authors.forename: Sebastiaan R D
authors.initials: SR
authors.lastname: Piers
authors.forename: Adrianus P
authors.initials: AP
authors.lastname: Wijnmaalen
authors.forename: C Jan Willem
authors.initials: CJ
authors.lastname: Borleffs
authors.forename: Carine F B
authors.initials: CF
authors.lastname: van Huls van Taxis
authors.forename: Joep
authors.initials: J
authors.lastname: Thijssen
authors.forename: Johannes B
authors.initials: JB
authors.lastname: van Rees
authors.forename: Suzanne C
authors.initials: SC
authors.lastname: Cannegieter
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Schalij
authors.forename: Katja
authors.initials: K
authors.lastname: Zeppenfeld
mesh_terms: D000368:Aged; D016009:Chi-Square Distribution; D017147:Defibrillators, Implantable; D004554:Electric Countershock / Q000295:instrumentation; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D015425:Myocardial Reperfusion; D009426:Netherlands; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D017180:Tachycardia, Ventricular / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D013997:Time Factors; D016896:Treatment Outcome