Frequency analysis of the ECG before and during ventricular fibrillation

Abstract

Frequency analysis of cardiac electrograms of dogs with ventricular fibrillation (VF) during complete cardiopulmonary bypass and coronary perfusion showed a power spectrum with a peak around 12 Hz and its higher harmonics, suggesting more organization than generally assumed. As a next step to see whether this conclusion could be of clinical use, we estimated in the same way power spectra of VF in patients. Pseudo three-dimensional displays of these "consecutive" spectra clearly showed a distinction between the ECG of a beating heart and the ECG during VF; both could be clearly distinguished from the noise of "loose" electrodes. During VF the power spectrum shows a peak around 6 Hz plus its higher harmonics. The spectrum did not change in character or basic frequency during relatively long periods (45 sec's).