Sudden cardiac death is one of the most important problems of modern cardiology. More than 50% of these deaths are caused by ventricular arrhythmias. It has been known for twenty years that ventricular late potentials (LP) might be the substrate for serious ventricular arrhythmias and prevalence of LP correlates closely, among the others, with myocardium necrosis. The purpose of the study was to assess the influence of applied therapy in acute phase of myocardial infarction on LP presence, evaluation of relationship between the degree of left ventricular LV (V) myocardium damage and LP occurrence and assessment if LP can be non-invasive reperfusion markers. 120 consecutive patients (20 women, 100 men, mean age 53.3) with first acute myocardial infarction (AMI) treated either with thrombolytic or non-thrombolytic therapy were enrolled into the study. The patients were divided into three groups. Group IA--patients treated with thrombolysis with non-invasive features of reperfusion (n = 30), group IB--patients treated with thrombolysis, without reperfusion features (n = 31) and group II--patients treated with non-thrombolytic therapy. Within 24 hours of admission signal-averaged ECG was recorded (before and after treatment) and 24-hour ECG monitoring and echocardiography were performed. The examinations were repeated before discharge (approximately 21 days after AMI). All patients were followed up for one year. The prevalence of LP was 16.7% in the group IA, 48.4% in the group IB and 57.6% in the group II (p < 0.001). LVEF was 48.9% in the group IA, 42% in the group IB and 43.9% in the group II (I vs IB vs II p < 0.001). Significant changes of LP parameters before and after thrombolysis were observed only in the group 1A (in 40% of patients) (tQRS--122.4 +/- 6.1 msec vs 104.1 +/- 7.1 msec p < 0.001, LAS--49.8 +/- 4.8 msec vs 30.7 +/- 4.7 msec p < 0.001, RMS--13.6 +/- 4.4 uV vs 29.1 +/- 8.3 uV p < 0.001). There was no statistical significance in ventricular arrhythmia assessment but there was marked correlation with LP occurrence in all groups. 1-year mortality rate was 6.7% in group IA, 12.9% in group IB and 8.5% in group II (NS).
Conclusions: Successful thrombolysis significantly reduces LP incidence in the late phase of myocardial infarction. LVEF correlates negatively with LP presence. LP presence in the first day of AMI may predict sudden cardiac death. LP occurrence can be significant non-invasive reperfusion markers.