Author + information
- Received July 30, 1990
- Revision received January 31, 1991
- Accepted April 8, 1991
- Published online September 1, 1991.
- John P. Bourke, MB, MRCPa,b,c,
- David A.B. Richards, MD, FRACP, FACC∗,a,
- David L. Ross, FRACP, FACCa,
- Elizabeth M. Wallace, BSca,
- Mark A. McGuire, MB, BS, BMedSc, FRACPa,1 and
- John B. Uther, MD, FRACPa
- ↵∗Address for reprints: David A. B. Richards, MD, Cardiology Unit, Westmead Hospital, Westmead, New South Wales 2145, Australia.
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 < 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 <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 anti-arrhythmic interventions.
- Received July 30, 1990.
- Revision received January 31, 1991.
- Accepted April 8, 1991.