Low-frequency skin microvascular oscillations: dynamics, synchronization and compliance with changes in vascular tone during the tilt test
Heading: Cardiology Article type: Original article
Authors: Mironov S.A., Kiselev A.R., Simonyan M.A., Shvartz V.A., Karavaev A.S., Borovkova E.l., Ishbulatov Yu.M., Popova Yu.V., Posnenkova O.M., Gridnev V.I.
Organization: Central Clinical Military Hospital (Moscow), Saratov State Medical University
The purpose is to study the dynamics of low-frequency oscillations (LF; basic frequency of about 0.1 Hz) in the spectra of fingerprint photoplethysmograms (PPG), their synchronization with a similar LF-rhythm in cardiointervalo-gram (CIG) and compliance with changes in vascular tone during the tilt test in healthy volunteers. Material and Methods. Synchronous cardiointerval recording, breathing recording, left shoulder rheovasography and PPG records from the palm surfaces of distal phalanges of anonymous fingers were analyzed, as well as central hemodynamics data by impedance rheocardiography in 30 healthy volunteers during the tilt test. Dynamics of LF-oscillations in PPG signals, their interaction (including synchronization) with similar oscillations in CIG and vascular tone parameters were studied. Results. At the stages of tilt test the values of LF-oscillations power in the spectra of PPG had no statistically significant differences. During the tilt test the index of synchronization of LF-oscillations increased (p<0.01). No correlations were found between the power of LF-oscillations in PPG spectra and vascular tone parameters. Conclusion. Absence of significant changes in LF-oscillations power in PPG spectra in the group of healthy volunteers at the stages of tilt test does not correspond to the dynamics of vascular tone parameters, estimated according to rheography data. At the same time, increased interaction between the autonomic regulation subsystems (heart rhythm — distal blood flow) was observed and resulted in the increase of of LF-oscillations synchronization.
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