Imperial College London
Alternate

ProfessorDarrelFrancis

Faculty of Medicine, National Heart & Lung Institute

Professor of Cardiology
 
 
 
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Contact

 

+44 (0)20 7594 3381d.francis Website

 
 
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Assistant

 

Miss Juliet Holmes +44 (0)20 7594 5735

 
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Location

 

Block B Hammersmith HospitalHammersmith Campus

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Summary

 

Publications

Citation

BibTex format

@article{Sands:2017:10.1164/rccm.201604-07610C,
author = {Sands, SA and Mebrate, Y and Edwards, BA and Nernati, S and Manisty, CH and Desai, AS and Wellman, A and Willson, K and Francis, DP and Butler, JP and Malhotra, A},
doi = {10.1164/rccm.201604-07610C},
journal = {American Journal of Respiratory and Critical Care Medicine},
pages = {237--246},
title = {Resonance as the mechanism of daytime periodic breathing in patients with heart failure},
url = {http://dx.doi.org/10.1164/rccm.201604-07610C},
volume = {195},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Rationale: In patients with chronic heart failure, daytime oscillatory breathing at rest is associated with a high risk of mortality. Experimental evidence, including exaggerated ventilatory responses to CO2 and prolonged circulation time, implicates the ventilatory control system and suggests feedback instability (loop gain > 1) is responsible. However, daytime oscillatory patterns often appear remarkably irregular versus classic instability (Cheyne-Stokes respiration), suggesting our mechanistic understanding is limited.Objectives: We propose that daytime ventilatory oscillations generally result from a chemoreflex resonance, in which spontaneous biological variations in ventilatory drive repeatedly induce temporary and irregular ringing effects. Importantly, the ease with which spontaneous biological variations induce irregular oscillations (resonance “strength”) rises profoundly as loop gain rises toward 1. We tested this hypothesis through a comparison of mathematical predictions against actual measurements in patients with heart failure and healthy control subjects.Methods: In 25 patients with chronic heart failure and 25 control subjects, we examined spontaneous oscillations in ventilation and separately quantified loop gain using dynamic inspired CO2 stimulation.Measurements and Main Results: Resonance was detected in 24 of 25 patients with heart failure and 18 of 25 control subjects. With increased loop gain—consequent to increased chemosensitivity and delay—the strength of spontaneous oscillations increased precipitously as predicted (r = 0.88), yielding larger (r = 0.78) and more regular (interpeak interval SD, r = −0.68) oscillations (P < 0.001 for all, both groups combined).Conclusions: Our study elucidates the mechanism underlying daytime ventilatory oscillations in heart failure and provides a means to measure and interpret these oscillations to r
AU  - Sands,SA
AU  - Mebrate,Y
AU  - Edwards,BA
AU  - Nernati,S
AU  - Manisty,CH
AU  - Desai,AS
AU  - Wellman,A
AU  - Willson,K
AU  - Francis,DP
AU  - Butler,JP
AU  - Malhotra,A
DO  - 10.1164/rccm.201604-07610C
EP  - 246
PY  - 2017///
SN  - 1073-449X
SP  - 237
TI  - Resonance as the mechanism of daytime periodic breathing in patients with heart failure
T2  - American Journal of Respiratory and Critical Care Medicine
UR  - http://dx.doi.org/10.1164/rccm.201604-07610C
UR  - http://hdl.handle.net/10044/1/63969
VL  - 195
ER  -
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