Contribution of the Lung to the Genesis of Cheyne‐Stokes Respiration in Heart Failure: Plant Gain Beyond Chemoreflex Gain and Circulation Time

Abstract

Background The contribution of the lung or the plant gain ( PG ; ie, change in blood gases per unit change in ventilation) to Cheyne‐Stokes respiration ( CSR ) in heart failure has only been hypothesized by mathematical models, but never been directly evaluated. Methods and Results Twenty patients with systolic heart failure (age, 72.4±6.4 years; left ventricular ejection fraction, 31.5±5.8%), 10 with relevant CSR (24‐hour apnea‐hypopnea index [ AHI ] ≥10 events/h) and 10 without ( AHI <10 events/h) at 24‐hour cardiorespiratory monitoring underwent evaluation of chemoreflex gain (CG) to hypoxia ( ) and hypercapnia ( ) by rebreathing technique, lung‐to‐finger circulation time, and PG assessment through a visual system. PG test was feasible and reproducible (intraclass correlation coefficient, 0.98; 95% CI , 0.91–0.99); the best‐fitting curve to express the PG was a hyperbola ( R 2 ≥0.98). Patients with CSR showed increased PG , (but not ), and lung‐to‐finger circulation time, compared with patients without CSR (all P <0.05). PG was the only predictor of the daytime AHI ( R =0.56, P =0.01) and together with the also predicted the nighttime AHI ( R =0.81, P =0.0003) and the 24‐hour AHI ( R =0.71, P =0.001). Lung‐to‐finger circulation time was the only predictor of CSR cycle length ( R =0.82, P =0.00006). Conclusions PG is a powerful contributor of CSR and should be evaluated together with the CG and circulation time to individualize treatments aimed at stabilizing breathing in heart failure.

Progressive cardiorespiratory dysfunction in Kv1.1 knockout mice may provide temporal biomarkers of pending sudden unexpected death in epilepsy (SUDEP): The contribution of orexin

“…Chronic intermittent hypoxia is associated with increased central chemosensitivity and probability of death in patients with heart failure . Central chemoreception promotes responses to repeated hypoxia and/or hypercapnia challenges, including increasing ventilation .…”

“…Chronic intermittent hypoxia is associated with increased central chemosensitivity and probability of death in patients with heart failure. [56][57][58] Central chemoreception promotes responses to repeated hypoxia and/or hypercapnia challenges, including increasing ventilation. [34][35][36] There are multiple central sites with chemoreceptive neurons, and orexin neurons in the lateral hypothalamus represents one such site.…”

A signal demodulation-based method for the early detection of Cheyne-Stokes respiration

“…The eAMI method [18] is the closest proposition to ours in the literature: both methods rely on amplitude modulation but differ in the employed techniques and the computed indexes. It has been completely implemented in MATLAB R2018a for comparison with the proposed method.…”

“…For example, a spectral decomposition algorithm of the instantaneous minute ventilation is proposed in [15][16][17] where periodic breathing has to be previously detected to be quantified. A method based on a standard amplitude demodulation scheme based on filters is presented in [18]. Those two methods can be noise-sensitive and only bring information on the amplitude of the modulation but does not specify any pattern characteristics such as the instantaneous frequency of the oscillation, thus cannot confirm a CSR pattern.…”

“…A panel of 15 patients with chronic heart failure was used to demonstrate the proof of concept. To assess the performances of the local detection and final classification, the results obtained by the new method were compared to those given by eAMI [18] and the opinion of CSR experts.…”