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Stimulated Stokes and Antistokes Raman Scattering in Microspherical Whispering Gallery Mode Resonators
Published on: April 4, 2016
Evidence for a central origin of the low-frequency oscillation in RR-interval variability
R L Cooley1, N Montano, C Cogliati
1Department of Internal Medicine, College of Medicine, University of Iowa, Iowa City 52242, USA.
Circulation
|August 26, 1998
Summary
Congestive heart failure (CHF) patients regain normal heart rate variability (HRV) low-frequency oscillations after left ventricular assist device (LVAD) implantation. This restoration suggests a fundamental property of autonomic outflow, independent of blood pressure and baroreflex.
Area of Science:
- Cardiovascular Physiology
- Autonomic Nervous System Function
- Medical Device Technology
Background:
- Short-term variability in RR interval and blood pressure exhibits low (LF) and high (HF) frequency oscillations.
- The arterial baroreflex is considered the primary driver of the LF component of RR variability.
- Severe congestive heart failure (CHF) is associated with diminished or absent LF oscillations in RR variability.
Observation:
- Spectral analysis of RR interval, blood pressure, and respiration was performed on two CHF patients before and after left ventricular assist device (LVAD) implantation.
- LF components of RR interval and blood pressure variability were absent in both CHF patients pre-LVAD.
- Post-LVAD implantation, RR interval spectral analysis revealed a restored, predominant LF oscillation in the native hearts, notably absent in the blood pressure profile.
Findings:
- The LF oscillation in the native heart's RR interval, absent in CHF, is restored during total circulatory support with an LVAD.
- This restored LF oscillation occurs without concurrent LF oscillations in blood pressure, suggesting it's independent of baroreflex mechanisms.
- The absence of LF oscillation in CHF is functional, reversible by LVAD circulation.
Implications:
- The LF oscillation in RR interval appears to be a fundamental property of central autonomic outflow.
- LVAD support can restore autonomic nervous system function related to heart rate variability in CHF patients.
- This study provides insights into the pathophysiology of autonomic dysfunction in heart failure and the potential of mechanical circulatory support to ameliorate it.
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