Association of short term heart rate spectral power with onset of spontaneous ventricular tachycardia or ventricular fibrillation

Heart rate (HR) variability immediately prior to the onset of a spontaneous ventricular tachycardia or ventricular fibrillation (VT/VF) may be higher. Power spectral estimation using periodogram technique was performed on HR obtained from 135 sets of 1000 RR intervals that preceded spontaneous onset of VT/VF and 125 control sets. Ten frequency bands, each of 0.1 Hz bandwidth were analyzed. Time course analysis of spectral power was also performed at 7 non-overlapping segments of 100 samples (50 seconds) each prior to time of onset of VT/VF (ONSET) and on control data sets. The RR interval rhythms associated with ONSET had higher power in all spectral bands compared to the control group (p<0.01). It was also found that spectral power increased suddenly in the 50 seconds before ONSET. A HR spectral analysis may be useful in predicting the ONSET