Abstract
In 13 decerebrate, artificially ventilated cats preganglionic sympathetic outflow to the heart was recorded with ECG and ventilation signal. A novel algorithm was implemented that extracts weighted events representing burst occurrences and their size. A multiple threshold strategy was used to separate bursts. Weighted events yielded count signals. Spectral analysis of the count signal revealed a predominance of a discharge synchronous to heart beat at cardiac frequency (CF≅3 Hz), a ventilation rhythm at the high frequency (HF≅0.3 Hz) of beat-to-beat variability, and in 9 of 13 cats a Mayer's wave lower frequency (LF). The CF component was ∼50% larger in power than both HF and also LF (when present). Spectral analysis at increasing count levels (i.e., with only the events with a weight ≥ the considered level) indicated that all rhythms were carried by burst activity and its modulations. A modulation index of HF over CF, MIHF/CF was extracted from dynamic (i.e., ventilation cycle by ventilation cycle) folded histograms of counts. MIHF/CF was significantly higher in the group without LF (0.65±0.20, mean±SD, n=4) than in that with LF (0.41±0.07, n=9). Burst activity can be a key element in the interactions between cardiovascular variability rhythms.
Original language | English |
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Title of host publication | Annual Reports of the Research Reactor Institute, Kyoto University |
Pages | 582-584 |
Number of pages | 3 |
Volume | 1 |
Publication status | Published - 2001 |
Event | 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society - Istanbul, Turkey Duration: Oct 25 2001 → Oct 28 2001 |
Other
Other | 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society |
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Country/Territory | Turkey |
City | Istanbul |
Period | 10/25/01 → 10/28/01 |
Keywords
- Beat-to-beat variability
- Burst activity
- Cardiac rhythm
- Sympathetic outflow
ASJC Scopus subject areas
- Energy Engineering and Power Technology
- Mechanical Engineering