Local scale exponents of blood pressure and heart rate variability by detrended fluctuation analysis: Effects of posture, exercise, and aging

Paolo Castiglioni, Gianfranco Parati, Andrei Civijian, Luc Quintin, Marco Di Rienzo

Research output: Contribution to journalArticle


Heart rate self-affinity is often assessed by detrended fluctuations analysis, obtaining two coefficients only: a short-term (α1) exponent and a long-term (α2) exponent. Our aim is to show the limits of this approach and alternatively propose the estimation of the whole spectrum of local exponents α(n) for heart rate and blood pressure. To illustrate the advantages of this approach, we assess the effects of autonomic activations and age on α(n). We measured ECG and arterial pressure in 60 volunteers for 10 min, considering three conditions at increasing sympathetic activation: supine rest, sitting, and sitting during exercise. We computed α(n) of R-R intervals and systolic, mean, and diastolic blood pressures, as the slope of the detrended fluctuations function in a log-log plot. Volunteers were divided into age groups and compared. Results indicate that: 1) α1 cannot be defined because short-term coefficients decrease with n, while α2 cannot be defined only for blood pressure during supine rest; 2) heart rate and blood pressure scaling structures differ during supine rest but not during exercise; and 3) age effects appear mainly in supine rest, explaining discr

Original languageEnglish
Article number4633671
Pages (from-to)675-684
Number of pages10
JournalIEEE Transactions on Biomedical Engineering
Issue number3
Publication statusPublished - Mar 2009



  • Autonomic nervous system
  • Cardiovascular system
  • Fractals
  • Hurst exponent

ASJC Scopus subject areas

  • Biomedical Engineering

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