TY - JOUR
T1 - Non-invasive model-based estimation of the sinus node dynamic properties from spontaneous cardiovascular variability series
AU - Porta, Alberto
AU - Montano, N.
AU - Pagani, M.
AU - Malliani, A.
AU - Baselli, G.
AU - Somers, V. K.
AU - van de Borne, P.
N1 - Funding Information:
Acknowledgment This study was supported by the Ministero dell'Universitfi e della Ricerca Scientifica e Tecnologica, grant COFIN-2000 (to N. Montano and A. Malliani), and Italian Space Agency grant ASI 336/2000 (to A. Malliani).
PY - 2003/1
Y1 - 2003/1
N2 - A non-invasive model-based approach to the estimation of sinus node dynamic properties is proposed. The model exploits the spontaneous beat-to-beat variability of heart period and systolic arterial pressure and the sampled respiration, thus surrogating the information from direct measures of neural activity. The residual heart period variability not related to baroreflex, to direct effects of respiration and to low frequency influences independent of baroreflex, is interpreted as the effect of the dynamic properties of the sinus node and modelled as a regression of the RR interval over its previous value. Therefore the sinus node transfer function is modelled by means of a filter with a real pole z = μ (and a zero in the origin). It was found that: first, in young healthy subjects the nodal tissue responded as a low-pass filter with μ = 0.76 ± 0.12 (mean ± SD); secondly, ageing did not significantly modify either its shape or gain at 0 Hz; thirdly, in heart transplant recipients, the dynamic transduction properties were lost (all-pass filter, μ = 0.06 ± 0.16, p < 0.001); fourthly, low-dose atropine left the sinus node dynamic properties unmodified; fifthly, high-dose atropine affected the dynamic transduction properties by increasing the gain at 0 Hz and rendering steeper its roll-off (the percent increase of μ with respect to baseline was 18.3 ± 22.3, p < 0.05).
AB - A non-invasive model-based approach to the estimation of sinus node dynamic properties is proposed. The model exploits the spontaneous beat-to-beat variability of heart period and systolic arterial pressure and the sampled respiration, thus surrogating the information from direct measures of neural activity. The residual heart period variability not related to baroreflex, to direct effects of respiration and to low frequency influences independent of baroreflex, is interpreted as the effect of the dynamic properties of the sinus node and modelled as a regression of the RR interval over its previous value. Therefore the sinus node transfer function is modelled by means of a filter with a real pole z = μ (and a zero in the origin). It was found that: first, in young healthy subjects the nodal tissue responded as a low-pass filter with μ = 0.76 ± 0.12 (mean ± SD); secondly, ageing did not significantly modify either its shape or gain at 0 Hz; thirdly, in heart transplant recipients, the dynamic transduction properties were lost (all-pass filter, μ = 0.06 ± 0.16, p < 0.001); fourthly, low-dose atropine left the sinus node dynamic properties unmodified; fifthly, high-dose atropine affected the dynamic transduction properties by increasing the gain at 0 Hz and rendering steeper its roll-off (the percent increase of μ with respect to baseline was 18.3 ± 22.3, p < 0.05).
KW - Atropine
KW - Cardiovascular control
KW - Cardiovascular variability
KW - Heart transplantation
KW - Parametric multivariate model
KW - Sinus node transfer function
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U2 - 10.1007/BF02343539
DO - 10.1007/BF02343539
M3 - Review article
C2 - 12572748
AN - SCOPUS:0037250783
SN - 0140-0118
VL - 41
SP - 52
EP - 61
JO - Medical and Biological Engineering and Computing
JF - Medical and Biological Engineering and Computing
IS - 1
ER -