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Summary: Added Spectral Features in ECGs From Patients With Ventricular Tachycardia
Detected by Phase and Group-Delay Analysis Over the Cardiac Cycle
R. Martin Arthur, Neal G. Kavesh, H. Dieter Ambos, Michael E. Cain
Washington University, St. Louis, MO
ABSTRACT
Fourier analysis of the signal-averaged ECG (SAECG)
has previously revealed significant differences in
magnitude spectra that differentiate patients with
ventricular tachycardia(VT) from those without VT. To
determine additional distinguishing features in the
frequency domain, we analyzed phase spectra of
SAECGs of sinus beats from 40 patients with VT, 41
without VT, and 20 normal controls. Unwrapped phase
spectra from SAECGs of the entire cardiac cycle were
calculated with respect to 3 fiducial points: the beginning
of the P wave, the mean delay for frequencies in the DC
to 100 Hz band, and the mean delay for frequencies in
the band which accounted for 97.5% of the energy in the
vector magnitude of the Frank SAECG leads. Phase
spectra of SAECGs from patients with VT differed from
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