title: Routine programmed electrical stimulation in survivors of acute myocardial infarction for prediction of spontaneous ventricular tachyarrhythmias during follow-up: results, optimal stimulation protocol and cost-effective screening.
abstract: Of 3,286 consecutive patients treated for acute myocardial infarction, electrophysiologic testing was performed in 1,209 survivors (37%) free of significant complications at the time of hospital discharge to determine their risk of spontaneous ventricular tachyarrhythmias during follow-up. Sustained monomorphic ventricular tachycardia was inducible by programmed electrical stimulation in 75 (6.2%). Antiarrhythmic therapy was not routinely prescribed regardless of the test results. During the 1st year of follow-up, 14 infarct survivors (19%) with inducible ventricular tachycardia experienced spontaneous ventricular tachycardia or fibrillation in the absence of new ischemia compared with 34 (2.9%) of those without inducible ventricular tachycardia (p less than 0.0005). During the extended follow-up period (median 28 months) of those with inducible ventricular tachycardia, 19 (25%) had a spontaneous electrical event; 37% of these first events were fatal. These results suggest that the most cost-effective strategy for predicting arrhythmia will be obtained by restricting electrophysiologic testing to infarct survivors whose left ventricular ejection fraction is less than 40% and using a stimulation protocol containing four extrastimuli. Electrophysiologic testing is the single best predictor of spontaneous ventricular tachyarrhythmias during follow-up in infarct survivors. The majority (94%) with a negative test benefit from the more reliable reassurance that all is well, whereas the 25% risk of electrical events in those with inducible ventricular tachycardia justifies a prospective trial of effective prophylactic antiarrhythmic interventions.
authors.affiliation: Cardiology Unit, Westmead Hospital, New South Wales, Australia.
authors.forename: J P
authors.initials: JP
authors.lastname: Bourke
authors.forename: D A
authors.initials: DA
authors.lastname: Richards
authors.forename: D L
authors.initials: DL
authors.lastname: Ross
authors.forename: E M
authors.initials: EM
authors.lastname: Wallace
authors.forename: M A
authors.initials: MA
authors.lastname: McGuire
authors.forename: J B
authors.initials: JB
authors.lastname: Uther
mesh_terms: D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D002304:Cardiac Pacing, Artificial; D003362:Cost-Benefit Analysis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000453:epidemiology; D011237:Predictive Value of Tests; D012307:Risk Factors; D013318:Stroke Volume / Q000502:physiology; D013610:Tachycardia / Q000453:epidemiology*; D014693:Ventricular Fibrillation / Q000453:epidemiology*
chemical_list: D000889:Anti-Arrhythmia Agents