Author + information
- Received November 7, 1986
- Revision received March 4, 1987
- Accepted March 16, 1987
- Published online August 1, 1987.
- J. Anthony Gomes, MD, FACC*,1,
- Stephen L. Winters, MD1,
- Debra Stewart, RN1,
- Steven Horowitz, MD, FACC1,
- Mark Milner, MD1 and
- Philip Barreca, BS1
- ↵*Address for reprints: J. Anthony Gomes, MD, Director, Electrophysiology and Electrocardiography Section, The Mount Sinai Medical Center, Box 1054, One Gustave L. Levy Place, New York, New York 10029.
A prospective study of the prognostic significance of the signal-averaged electrocardiogram (ECG), left ventricular function and 24 hour Holter ECG monitoring was performed in 102 patients (age 63 ± 11 years) after myocardial infarction. The signal-averaged ECG (40 Hz high pass bidirectional filtering) was obtained 10 ± 6 days after the acute myocardial infarction and all three tests were performed within 72 hours of each other. Ejection fraction was determined by radionuclide ventriculography. An abnormal signal-averaged ECG was seen in 44% of patients; abnormal ejection fraction (<40%) in 52% and high grade ectopic activity (>10 ventricular premature depolarizations/h or couplets, or nonsustained ventricular tachycardia, or a combination of these) in 62%.
During a 12 ± 6 month follow-up period, 15 patients (14.7%) had an arrhythmic event defined as sustained ventricular tachycardia or sudden cardiac death, or both. The event rates were higher in patients with an abnormal versus a normal signal-averaged ECG (29 versus 3.5%, p = 0.003), an abnormal versus a normal ejection fraction (24 versus 6%, p = 0.001) and the presence versus the absence of high grade ectopic activity (23 versus 9%, p = 0.09). Patients with an abnormal signal-averaged ECG and an abnormal ejection fraction had a significantly higher (p = 0.0007) event rate than did patients in whom both the tests were normal (36 versus 0%; odds ratio 30.1). Patients with an abnormal signal-averaged ECG, abnormal ejection fraction and presence of high grade ectopic activity had an event rate of 50%, whereas there were no events in patients in whom all three tests were normal (p = 0.01, odds ratio 19). When the stepwise Cox survivorship analysis was used with regression covariates, the ejection fraction, quantitative signal-averaged variables and presence of nonsustaihed ventricular tachycardia on 24 hour Holter monitoring had the most significant relation to an arrhythmic event.
In conclusion: 1) The signal-averaged ECG defines a high risk group of patients; however, the combination of an abnormal signal-averaged ECG, abnormal ejection fraction and the presence of high grade ectopic activity identified the highest risk subset of patients for sustained ventricular tachycardia or sudden death, or both, in the first year after myocardial infarction. 2) This study provides a new noninvasive index for selecting for intervention a high risk subset of patients after myocardial infarction.
- Received November 7, 1986.
- Revision received March 4, 1987.
- Accepted March 16, 1987.
- American College of Cardiology Foundation