Influence of the Main Filter on QRS-amplitude and Duration in Human Electrocardiogram

Accurate measurement of electrocardiograms (ECG) is critical for effective diagnosis of patient’s cardiac functions. Detailed examination of filters’ effects on ECG accuracy, reproducibility and robustness covering a wide range of available commercial products can provide valuable information on the relationship between quality and effectiveness of filters, and assessments of patients’ cardiac functions. In this study, ECG device with 12 leads and built-in filters used for ECG measurements was assessed on human volunteers. Results showed that with respect to measuring QRS wave duration and R-amplitude variation, there was a 4 % inaccuracy when the main filter was ON and OFF, and R-amplitude variation was most pronounced in the V4 lead. Accordingly, variability of R-amplitude and length of QRS wave can be reduced by the use of appropriate lead, and filter activation during the ECG assessment.