Filtering techniques for ventricular late potentials analysis

This work presents a comparative study of filtering techniques for ventricular late potentials (VLP) analysis. We compare linear-phase FIR and IIR filters, with bidirectional nonlinear-phase IIR filters (IIR-BF). The comparison is done in terms of the recovered VLP signal energy at the output of the different filters, using a simulated QRS complex with added VLP as input signal. The comparison shows that the IIR-BF are the filters that best perforine. This behaviour is due to the nonlinear phase of the IIR-BF and to the temporal distribution of VLP with respect to the QRS complex. Group delay at QRS frequencies Is higher than at VLP ones. It produces a temporal separation of these signals that makes the IIR-BF the more suitable filters for VLP analysis.