Although in advanced chronic congestive heart failure (CHF) very low frequency (2 natural logarithm [ln]) compared either to patients without VLF (4.0 ± 1.3 ms2 ln) or to controls (5.9 ± 0.7 ms2 ln), higher percentage of power within VLF band (86.3 ± 8.3% vs 77.5 ± 7.9% and 61.5 ± 14.1%) and a markedly impaired coherence between RR interval and systolic blood pressure variability within the LF band (0.26 ± 0.10 vs 0.42 ± 0.18 and 0.63 ± 0.15, in patients with vs without VLF peak and controls, respectively). Patients with VLF had significantly increased hypoxic chemosensitivity, and hyperoxic conditions were able to decrease VLF power and abolish the VLF rhythm in 5 of 6 patients with CHF. Discrete VLF oscillations in RR variability are common in patients with advanced CHF and appear to be related to severely impaired autonomic regulation and suppression of baroreceptor function, with enhancement of hypoxic chemosensitivity. We hypothesize that this rhythm represents an enhanced chemoreflex harmonic oscillation in CHF patients, which may have application for arrhythmogenesis.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine