Journal of Computational Neuroscience

, Volume 28, Issue 3, pp 557–565 | Cite as

Fluctuations of the fractal dimension of the electroencephalogram during periodic breathing in heart failure patients

  • Roberto Maestri
  • Maria Teresa La Rovere
  • Elena Robbi
  • Gian Domenico Pinna


The physiological mechanisms responsible for periodic breathing (PB) in heart failure (HF) patients are still debated. A role for rhythmic shifts in the level of wakefulness has been suggested, but their existence has never been proven. In this study we investigated the existence of an oscillation in EEG activity during PB in these patients and assessed its relationship with the ventilatory oscillation. EEG activity was measured by the fractal dimension (FD) and by a spectral technique (weighted mean frequency, WMF) in 17 stable HF patients (mean age ± SD: 57±10 yrs, NYHA class: 2.6 ± 0.4, LVEF: 24 ± 6%), with sustained PB during supine rest. The relationship between minute ventilation (MV) signal and FD and WMF was assessed by coherence analysis. Most patients (10/17) showed a well defined oscillation in FD and WMF at the frequency of PB closely linked (coherence > 0.7) with the oscillation of MV. In the remaining patients, neither FD nor WMF showed a clear oscillatory pattern synchronous with MV. Overall, the two EEG-derived parameters showed the same coherence with the ventilatory oscillation (mean coherence ± SD: 0.65 ± 0.25 vs 0.66 ± 0.23, for FD and WMF respectively, p = 0.44). Our results provide evidence that during PB in HF patients, EEG activity often, but not always, fluctuates synchronously with the ventilatory oscillation. These fluctuations can be effectively detected by the fractal dimension, but classical spectral methods provide substantially the same information. Other mechanisms, particularly chemical instability in the respiratory control system, are likely to play a role in the genesis of PB.


EEG Spectral analysis Fractal dimension Nonlinear methods Periodic breathing Heart failure 


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Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Roberto Maestri
    • 1
  • Maria Teresa La Rovere
    • 2
  • Elena Robbi
    • 2
  • Gian Domenico Pinna
    • 1
  1. 1.Department of Biomedical EngineeringS. Maugeri Foundation, IRCCS, Scientific Institute of MontescanoMontescanoItaly
  2. 2.Department of CardiologyS. Maugeri Foundation, IRCCS, Scientific Institute of MontescanoMontescanoItaly

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