Prediction of life-threatening arrhythmia in patients after myocardial infarction by late potentials, ejection fraction and Holter monitoring.

In order to compare the prognostic significance of late potentials (LPs) on signal-averaged electrocardiogram (SA-ECG), left ventricular ejection fraction (EF) and 24-hour Holter monitoring (HM) following myocardial infarction, a prospective study on 60 patients (age 61.7 +/- 8.02 years old) just after acute myocardial infarction (AMI) was done. LPs, EF and HM were performed in all patients. Coronary arteriography had been done in 25 patients. The results showed that LPs were associated with a slightly higher incidence of life-threatening arrhythmia (34.8%) than HM (28.6%) and EF (25%). During the follow-up period (10 +/- 6 months), 9 patients had serious ventricular arrhythmic events, among whom 3 had sudden death due to ventricular fibrillation. The event rate in patients with abnormal LPs was higher than in patients with normal LPs (p = 0.01, odds ratio = 19.2). The study showed that there was no correlation between abnormal LPs and sex, age, number of narrowed coronary arteries, ventricular aneurysm, location of myocardial infarction, or EF alone. But there was a correlation between abnormal LPs and high grade ventricular ectopic activity detected by HM (r = 0.62899, p = 0.024). In addition, the combination of abnormal values of LPs, EF and HM could predict sustained ventricular tachycardia or sudden death in the first year after myocardial infarction with very high sensitivity (100%) as well as high specificity (p = 0.0009, odds ratio = 19).