Comparison of individual lead and combined lead frequency parameters of signal averaged electrocardiograms

Short-time Fourier analysis was performed on signal-averaged electrocardiograms (SAEs) for subjects with and without sustained ventricular tachycardias (SVTs). The ratio of low frequency (0-25 Hz) to high frequency (25-50 Hz) was computed for a 100-ms window moved through the SAE. This was done for each of the three orthogonal leads. These ratios were tested to see if the could distinguish between subjects with and without SVT. Also, for each subject, a geometric mean of the three lead ratios was computed at each shift, to see if this parameter could distinguish the two groups.<
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