Korean Circ J.  2007 Sep;37(9):443-448. 10.4070/kcj.2007.37.9.443.

Spontaneous Baroreflex Sensitivity and Multifractal Hurst Analysis of Heart Rate

• Kim JS
• Jeoung EY
• Yum MK
• Kim NS
• Kim JS

• KMID: 2093982
• DOI: http://doi.org/10.4070/kcj.2007.37.9.443

Abstract

BACKGROUND AND OBJECTIVES: This study was designed to examine whether the multifractal Hurst exponents of heart rate can estimate activating and deactivating spontaneous baroreflex sensitivity (SBRS).
SUBJECTS AND METHODS
Age and sex matched 24 healthy volunteers were placed in the supine position and head-up tilt position for 30 minutes, and the systolic blood pressure and heart rate were measured in an noninvasive manner. When the RR interval (RRI) sequence and systolic pressure sequence simultaneously increased or decreased for more than three successive beats, the slope of the linear regression line of systolic blood pressure and RR interval sequence was defined as the value of spontaneous baroreflex sensitivity (SBRS). From the RR intervals, very short-term (alpha range, < or =12 heartbeats), short-term (beta range, > or =12 heartbeats), and the multrifractal Hurst exponents were calculated to determine the linear correlation.coefficients for SBRS.
RESULTS
In the supine position, the linear correlation coefficients (p) of SBRS and H-5alpha, H-4alpha, H-3alpha, H-2alpha, H-1alpha, H1alpha, H2alpha, H3alpha, H4alpha, H5alpha were -0.195 (NS), -0.207 (NS), -0.232 (NS), -0.282 (NS), -0.355 (NS), -0.621 (0.003), -0.650 (0.001), -0.677 (0.001), -0.699 (0.0006) and -0.708 (0.0005), respectively. In the tilting position, the linear correlation coefficients of SBRS and H-5beta, H-4beta, H-3beta, H-2beta, H-1beta, H1beta, H2beta, H3beta, H4beta, H5beta were 0.024 (NS), 0.020 (NS), 0.010 (NS), -0.028 (NS), -0.193 (NS), -0.627 (0.0034), -0.607 (0.0045), -0.598 (0.0053), -0.572 (0.0084) and -0.539 (0.0141), respectively.
CONCLUSION
Some of the very short-term and short-term generalized Hurst exponents, such as H5alpha and H1beta, can be used for the estimation of spontaneous baroreflex sensitivity during patient placement in the supine and head-up tilt position, respectively.

Keyword

Baroreflex; Heart rate; Blood pressure

MeSH Terms

Baroreflex*
Blood Pressure
Healthy Volunteers
Heart Rate*
Heart*
Humans
Linear Models
Supine Position