Intraoperative Spectral Analysis of Ventricular Potentials During Sinus Rhythm and Ventricular Tachycardia
We determined the frequency spectra of ventricular potentials obtained in patients with recurrent sustained ventricular tachycardia (VT) undergoing cardiac electrosurgery. Recordings were obtained from direct myocardial bipolar electrodes inserted at locations distant from the site of arrhythmogenesis. Analyses of standard filtered (30–500 Hz), and wideband (0.5–2500 Hz) recordings were performed using a FFT analyser during sinus rhythm and VT.
In eleven patients studied, the spectra of standard recordings during sinus rhythm consisted of a broad peak having a center frequency between 20 and 30 Hz, with an average of 24 ± 4 Hz. Spectra of wideband recordings was substantially lower due to the large T wave component. During VT the spectral peaks of ventricular potentials shifted to lower frequencies, with an average for standard recordings of 18 ± 5 Hz. The observations are consistent with a reduction of myocardial conduction velocity during VT or delayed activation at local or distant sites.
KeywordsVentricular Tachycardia Sinus Rhythm Conduction Velocity Beth Israel Medical Ventricular Potential
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