A new noninvasive index to predict sustained ventricular tachycardia and sudden death in the first year after myocardial infarction: based on signal-averaged electrocardiogram, radionuclide ejection fraction and Holter monitoring.
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 (less than 40%) in 52% and high grade ectopic activity (greater than or equal to 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).(ABSTRACT TRUNCATED AT 250 WORDS)
D000368:Aged; D003645:Death, Sudden / Q000209:etiology*; D004562:Electrocardiography / Q000379:methods; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D011379:Prognosis; D011446:Prospective Studies; D011877:Radionuclide Imaging; D013318:Stroke Volume; D013610:Tachycardia / Q000209:etiology* / Q000503:physiopathology