摘要：The aim of this study was to assess the effect of filtering techniques on the time-domain
analysis of the ECG. Multi-lead ECG recordings obtained from chronic atrial fibrillation
(AF) patients after successful external cardioversion have been acquired. Several high-pass filtering
techniques and three cut-off frequency values were used: Bessel and Butterworth four-pole and
two-pole bidirectional and unidirectional filters, at 0.01, 0.05 and 0.5 Hz low cut-off frequency. As
a reference, a beat-by-beat linear piecewise interpolation was used to remove baseline wander, on
each P-wave. Results show that ECG filtering affects the estimation of P-wave duration in a manner
that depends upon the type of filter used: particularly, the bidirectional filters caused negligible
variation of P-wave duration, while unidirectional ones provoked an increase higher than 8%.
关键词：atrial fibrillation, digital signal processing, electrocardiography.
