Indicator of myocardial ischemia based on the mean power of ECG low frequency content: comparison with ST segment trend

In order to cause myocardial ischemia, the left anterior descending coronary artery was occluded and released two times in twelve dogs. The occlusion - release times and the ECG were recorded. Spectral content in the range of 1 to 10 Hz was obtained by means of a digital filter. After filtering, the mean power was determined and plotted in normalized trend curves. Averaged beats were calculated, one per epoch per lead, and used to obtain ST level trend plots. The events true-occlusion, late true-occlusion, false-occlusion, true-reperfusion and false-reperfusion were defined according to the arterial status and then counted. It was concluded that the indicator based on ECG low-frequency content can not replace the ST segment trend. However, it should be suitable to improve decision-making when an alternative therapy could be necessary.