TIME-FREQUENCY ANALYSIS OF VENTRICULAR LATE POTENTIALS

The time-frequency characteristics are studied of averaged and filtere d ECG records from 21 patients with sustained ventricular tachycardia and 29 healthy control subjects. Simulated data as well as real ECG re cords reveal the detection accuracy of the wavelet transform of signal s with late potentials. The wavelet-transforms of preprocessed ECG sig nals are plotted in the time-frequency plane. These representations of the signals are well suited to describe the different characteristics of the patients and healthy subjects. A quantitative discrimination w as performed with a sensitivity of 90% and a specificity of 72% by the energy underneath the squared modulus of the time-frequency distribut ion plots of the computed wavelet transforms.