High-frequency potentials in mid-QRS during reperfusion therapy of acute myocardial infarction using thrombolytic agents

The high-frequency QRS complex was examined in patients during reperfusion therapy of acute myocardial infarction using thrombolytic agents. Averaged high frequency ECG waveforms were obtained for consecutive time intervals (about 5 minute each) during the recording period and the root-mean-square (RMS) voltage over the QRS of the “precordial complex” was calculated for each segment. In nine patients there was statistically significant increase in the RMS voltage over the high frequency QRS complex. In 13 patients the change was not significant and in 3 patients drug administration was associated with a decrease in RMS voltage. It seems that the high-frequency QRS potentials may be useful in diagnosing the effect of reperfusion therapy of acute myocardial infarction using thrombolytic agents and also in the assessment of the efficacy of new thrombolytic agents