A multiresolution wavelet method for characterisation of ventricular late potentials

The authors present a method for ventricular late potentials (VLP) detection and characterisation using the Daubechies wavelets and the Newland harmonic and musical wavelets. The method is based on a wavelet multiresolution scheme, where the energy content of the beat-by-beat TP and ST segments of the high-resolution electrocardiogram (HR-ECG) are compared at different resolutions, with relative energy increases interpreted as VLP. An objective figure, the factor of normality, is generated for ready clinical use. These results are compared to the ones obtained with the application of the spectrogram and the Choi-Williams transform, using the spectro-temporal mapping for the VLP study. The factor of normality generated by the wavelet multiresolution scheme proved to be more sensitive, in the authors' study cases, compared to the time-frequency and the Simson methods.