2024 Volume 44 Issue 2 Pages 242-247
The ECG is an essential clinical monitor. Although a 12-lead ECG is performed preoperatively, the intraoperative ECG waveform often differs from the preoperative ECG waveform from the start of monitoring. This is partly due to the different testing environment, but also because strong ECG filtering is used intraoperatively. In other words, the filtering function, which is designed to remove noise and make the waveform easier to see, can detract from the original ECG waveform. In the case of waveforms on an unscaled monitor screen, distortion of the waveform due to filtering may induce incorrect interpretation. Especially in children, filtering often causes the R wave to appear lower and the T wave to appear relatively elevated. When interpreting ECG waveforms during anesthesia, it is important to be aware of the effects of filtering.
