SIGNAL-AVERAGED ELECTROCARDIOGRAPHY FOR PARAMETRIC EVALUATION

Abstract

The Signal averaged Electro cardiography has become a widely accepted technique for noninvasive risk assessment in patients prone to ventricular tachycardia (VT). It helps in detecting late potentials (microvolt level signals) which are high frequency signals present in the terminal portion of QRS Complex. , These signals correlate strongly with VT. After enhancing the signal-to-noise ratio through averaging process, the analysis has been carried out in time and frequency domain and the results are compared. The results from both the domains revealed that both methods have value for identification of patients with sustained VT. The data on which the analysis has been carried out has been taken from CSE library. In time domain analysis, the vector magnitude of filtered XYZ leads is used to measure time and amplitude parameters characterizing the terminal QRS complex. In frequency domain a fast Fourier transform (FFT) is performed on the QRS complex and terminal portion of QRS separately to determine frequency spectra and calculate derived spectral parameters