Analysis of the signal averaged ECG in the time-frequency domain

The detection of Ventricular Late Potential (VLP) activity within the terminal region of the QRS complex provides an indicator of a patient's susceptibility to Ventricular Tachycardia. In this investigation the signal averaged ECG was analysed in the time-frequency and time-scale domains, using the exponential distribution and the continuous wavelet transform respectively. Differences in the energy distribution between the patients with VLPs and without were observed. These differences were quantified by calculating the percentage of energy in different regions of the time-frequency plot. The results suggest that the proposed method could be a useful and possibly advantageous tool to aid VLP detection.