DEPARTMENT OF MECHANICS AND APPLIED MATHEMATICS
ANALYSIS OF HEART RATE VARIABILITY
HEAD OF THE PROJECT Jaan KALDA, Ph.D.
DESCRIPTION
The heart rate variability (HRV) has been studied extensively during the last 15 years. At the present time, the so called Holter monitoring is widely used in medical practice. The ECG is registered during 24 hour. The sequences of RR-intervals (as well as all the arrhythmic signals) are registered.
In medical practice, the following parameters are generally taken into account:
- the number of arrhythmic signals;
- the mean heart rate for day and for night (22.00-07.00);
- the variance of the heart rate for day and for night (22.00-07.00).
- the spectral amplitudes of the high frequency and low frequency Fourier components.
Meanwhile, it is widely accepted that there are more complex statistical characteristics of the RR-sequences which are also affected by the heart diseases and can provide a considerable amount of additional diagnostically important information. Although in principle the techniques of non-linear dynamics have been shown to be powerful tools for characterization of various complex systems, no major breakthrough has yet been achieved by their application to bio-medical data including HRV analysis.
The aim of the present project is to find the best statistical characteristics of long-time series of RR-intervals from the diagnostical point of view. More specifically, the output parameters should be as sensible as possible with respect to the several heart diseases.
The figure demonstrates some of our results: 12 healthy children (mean age 11,5±3,3 years, 6 children (mean age 11,5±1,9 years) with clinically documented sinus node disease (SND) and 14 children of different diagnosis (mean age 11,5±5,1 years) are investigated. The time-domain and frequency-domain parameters of HRV are compared with the new characteristics (LPDD8PS).
RESEARCH STAFF
- J. Kalda (Institute of Cybernetics)
- M.Vainu (Tallinn Diagnostic Centre)
- M.Laan (Nõmme Children Hospital)
- M. Säkki (Institute of Cybernetics, student at Tartu University)
PUBLICATIONS
- Research Report Mech 180/98: Kalda J., Vainu, M., Säkki, M., "On the analysis of the heart rate variability". 13 p.;
- Conference thesis "The methods of non-linear dynamics in the analysis of heart rate variability in children," M.Vainu, J.Kalda, M.Laan, M. Säkki, S.Tarraste, XXth Congress of the European Society of Cardiology (1998).
- The project has just been launched, papers for refereed journals are under preparation.
07/04/1998 webmaster