Time-frequency distribution of heart rate variability below 0.05 Hz by Wigner-Ville spectral analysis in congestive heart failure patients

The Wigner-Ville spectral analysis was utilized to demonstrate a high- resolution time-frequency distribution of heart rate variability below 0.05 Hz. There are different time-frequency characteristics between the normal subject and the patient with severe congestive heart failure. The former consists of multiple and broad-band spectral peaks, while the latter presents unique spectral peaks. Based on Bayes theory, a classifier for the unique spectral peaks was developed. After the beneficial improvement with low-dose beta-blockers, the unique spectral peaks had disappeared or the time of occurrence was reduced in most patients.