Interpolation over ectopic beats increases low frequency power in heart rate variability spectra

The authors compared spectra of heart rate variability (HRV) computed from 24 and 48 hour Holter tapes on 34 patients with congestive heart failure. Spectra on each patient were computed in two ways: (A) Segments with ectopic beats were included in the analysis. In this method, the intervals corresponding to ectopic beats and three beats following the last ectopic beat were computed by interpolation, and (B) Segments with ectopic beats were discarded. Spectral components of HRV in the low (0-0.05 Hz) and mid (0.05-0.15 Hz) frequency ranges were significantly (p<0.05) higher in method A than in method B. High (0.02-0.5 Hz) frequency components of the spectra were not significantly different between these two types of analysis.<
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