Abstract
Little is known about the changes in upper airway calibre in Cheyne–Stokes respiration (CSR) during sleep in patients with congestive heart failure. This study aimed to test the hypothesis that upper airway closure occurs during central CSR events, by assessing upper airway calibre during sleep using the forced oscillation technique (FOT).
Nine males with compensated heart failure (left ventricular ejection fraction mean±sem 27.9±5.1%) and predominant central CSR (apnoea/hypopnoea index 43.9±4.2 events·h−1) were studied during overnight polysomnography, which included pneumotachography, inductance plethysmography or oesophageal pressure and FOT-derived impedance signal (|Z|).
Baseline |Z| values during stable breathing in stage 2 sleep were 11.0±1.3 cmH2O·s·L−1. Mean |Z| increased to 31.9±6.7 cmH2O·s·L−1 during obstructive apnoeas (7% of events, n=46). Increases in |Z| consistent with upper airway narrowing (more than two-fold baseline) were common during central apnoeas (50±12% of events) occurring in the middle or end of apnoeas and occurred during some central hypopnoeas (16±10% of events), typically in the expiratory phase.
These findings indicate that in heart failure patients, reductions in upper airway calibre are common during CSR apnoeas, and may also occur during central hypopnoeas.
Footnotes
Support Statement
This study was funded by l'Association Pulmonaire du Québec and by an operating grant from the Canadian Institutes of Health Research through its University Industry Program (UI-14909) in partnership with Respironics Inc., ResMed Inc. and Tyco Healthcare.
Statement of Interest
A statement of interest for R.J. Kimoff and the study itself can be found at www.erj.ersjournals.com/site/misc/statements.xhtml
- Received April 7, 2011.
- Accepted April 11, 2012.
- ©ERS 2012