Spectral analysis of the entire cardiac cycle from signal-averaged ECGs for the detection of patients prone to ventricular tachycardia

To enhance frequency resolution and obviate the need for window functions in the analysis of short ECG segments, performed spectral analysis of the entire cardiac cycle. The cardiac cycles for the X, Y, and Z leads were digitally filtered to reduce dominant low-frequency components and then transformed with a discrete Fourier transform. Spectral plots from patients prone to ventricular tachycardia (VT) differed markedly from plots from patients without VT. It is found that spectral analysis of the entire cardiac cycle allows improved frequency solution, elimination of smearing associated with window functions, and interrogation of the entire biological interval.