Aim of the study-To evaluate influence of the skeletal muscle activity (SMA) on time and frequency domain properties of ECG during VF.Materials and methods-We studied the first 9 minutes of electrically induced VF (N=7). We recorded Lead II ECG, 247 unipolar epicardial ventricular electrograms (UEGs) and 3 bipolar skeletal electromyograms (EMGs) near the positions of the ECG electrodes (sampling rate, 500Hz). We reconstructed ECG (RECG) from UEGs using forward-solution transformation matrix. Spectral properties of ECG, RECG, UEGs and MEGs were assessed in the range 2−250Hz by the median frequency (MF) and the upper limit of frequency range containing 99% of spectral energy (F lim (99)). Scaling exponent of ECG, RECG and EMGs was calculated in the ranges of 1−8 and 5−20 sampling intervals (ScE 1−8 and ScE 5−20 , respectively). Conclusion-SMA significantly contributes to ECG during VF and can bias metrics used for assessment of VF organization.
Results-We observed non-monotonic increases in MF and