[The prognostic significance of post myocardial infarction dysrhythmias and left ventricular dysfunction is well established. We studied the role of late potentials to predict these two abnormalities. A prospective study of the relationship between signal averaged electrocardiogram, left ventricular function and 24 hour Holter ECG monitoring was performed in 39 patients 16,3 + 17,7 days and 16,3 +8,9 months after myocardial infarction. The late potentials were determined by the following parameters: duration of the high-frequency and low amplitude signals (HFLA), voltage in the terminal 40 ms (RMS) and duration of filtered QRS waves (QRS). The left ventricular function was measured by 2D-echocardiography and the rhythm disturbances were detected by Holter ECG monitoring or by our self-developed on-line arrhythmia monitoring. No difference was noted in age (63 versus 58 years, NS), and in the three late potential parameters (HFLA: 34 versus 34 ms, NS; RMS: 43 versus 38 uv, NS; QRS: 109 versus 114 ms, NS) between the groups of patients with normal( 1 group: EF > 40%) and abnormal (2nd group: EF < 40%) left ventricular function.
There was a significant difference in all three late potential parameters between the two groups of patients (A. and B. groups) based on the appearance of ventricular rhythm abnormalities (HFLA: 43 versus 31 ms, p<0,01; RMS: 24 versus 47 uv,p<0,05; QRS: 121 versus 106 ms, p<0,01). High resolution electrocardiography may be of prognostic value in selecting a high risk subset of patients (ventricular arrhythmias, sudden death) after myocardial infarction. ]