Related Experiment Video
Updated: Jun 18, 2026

Integration of Brain Tissue Saturation Monitoring in Cardiopulmonary Exercise Testing in Patients with Heart Failure
Published on: October 1, 2019
The effect of posture on Cheyne-Stokes respirations and hemodynamics in patients with heart failure
Bruce A G Soll1, Khung Keong Yeo, James W Davis
1Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA. bsoll@queens.org
Study Objectives:
Cheyne-Stokes respirations occur in 40% of patients with heart failure. Orthopnea is a cardinal symptom of heart failure and may affect the patient's sleeping angle. The objective of this study was to assess the respiratory and hemodynamic response to sleeping angle in a group of subjects with stable heart failure.
Design:
Twenty-five patients underwent overnight polysomnography with simultaneous and continuous impedance cardiographic monitoring. Sleeping polysomnographic and impedance cardiographic data were recorded.
Setting:
The study was conducted in a sleep center.
Patients:
All 25 patients had clinically stable heart failure and left ventricular ejection fractions < 40%.
Interventions:
The patients slept at 0 degrees, 15 degrees, 30 degrees, and 45 degrees in random order.
Measurements And Results:
Seventeen patients had Cheyne-Stokes apneas (index > 5/h) and 23 patients had hypopneas (index > 5/h). The hypopnea index showed no response to sleeping angle. The Cheyne-Stokes apnea index decreased with increasing sleeping angle (P < 0.001). This effect was seen only during supine sleep and non-rapid eye movement sleep and was absent in non-supine sleep, rapid eye movement sleep, and during periods of wakefulness. Thoracic fluid content index and left ventricular hemodynamics measured by impedance cardiography showed no response to sleeping angle.
Conclusions:
Changing the heart failure patient's sleeping angle from 0 degrees to 45 degrees results in a significant decrease in Cheyne-Stokes apneas. This decrease occurs on a constant base of hypopneas. The changes in Cheyne-Stokes apneas are not related to changes in lung congestion and left ventricular hemodynamics.
Related Concept Videos
Alterations in Respiration II
In Biot's breathing, the respiratory rate and depth are irregular, alternating between periods of deep gasping and apnea. Common causes include...
Physical Assessment of the Respiratory Tract II: Inspection
Chest Configuration
The chest configuration can...
Heart Failure VII: Nursing Interventions
Factors Affecting Respiration
Heart Failure VI: Adjunct Therapies
Imbalances in Cardiac Output
CHF can occur due to the failure of either side of the heart. Left-side failure leads to pulmonary congestion—the right side continues to send blood...
