Cheyne-Stokes Respiration (CSR) is a cyclical pattern of breathing characterized by progressively deeper and sometimes faster breaths that alternate with periods of very shallow or absent breathing. While it can occur when a person is awake, this pattern is most commonly observed during sleep, where it is classified as a form of central sleep apnea. Its presence generally signals issues with the body’s circulatory or central nervous systems.
The Distinctive Breathing Pattern
The pattern of Cheyne-Stokes Respiration is a predictable, three-part cycle. The entire cycle typically repeats every 45 to 90 seconds, allowing for repeated disruptions to the body’s gas exchange. The first phase is known as the crescendo, where the depth and rate of breaths gradually increase with each inhalation.
Following the crescendo is the decrescendo phase, during which the patient’s breathing progressively decreases in both depth and rate. This waning period leads directly into the third phase: central apnea. During this apnea, breathing completely stops for ten seconds or more, or is replaced by central hypopnea.
The cycle is a manifestation of unstable ventilatory control, which causes the body to overcompensate for changes in blood gas levels. The apnea allows carbon dioxide levels to rise, which then stimulates the brain’s respiratory center to initiate the hyperventilation of the crescendo phase. This excessive breathing then rapidly lowers the carbon dioxide level, causing the respiratory drive to drop off again and restart the cycle.
Primary Underlying Medical Conditions
Cheyne-Stokes Respiration is primarily a consequence of underlying conditions that affect the circulatory or neurological systems. The most frequent cause is congestive heart failure, where the heart’s inability to pump blood efficiently leads to a circulatory delay. This delay means that the blood carrying information about carbon dioxide levels takes too long to travel from the lungs to the brain’s respiratory center.
Because of this prolonged transit time, the brain receives delayed feedback, causing it to overreact to the chemical signals in the blood. This instability results in the characteristic waxing and waning pattern. Cheyne-Stokes breathing is observed in up to 50% of people with heart failure.
Damage to the central nervous system (CNS), such as from a stroke, brain tumor, or traumatic brain injury, can also directly impair the respiratory control centers, leading to CSR. A temporary, non-disease-related cause can also occur in otherwise healthy individuals exposed to high altitude, where the low oxygen environment similarly disrupts the respiratory feedback loop.
Diagnostic Confirmation Methods
Confirmation of Cheyne-Stokes Respiration is typically achieved through specialized monitoring. Polysomnography, commonly known as a sleep study, is considered the gold standard diagnostic tool. This overnight test records a comprehensive set of physiological parameters, including brain activity, heart rate, and movements, alongside detailed respiratory measurements.
The sleep study measures the rate and depth of breathing, as well as the blood oxygen saturation levels. For a definitive diagnosis, the American Academy of Sleep Medicine requires observing at least three consecutive central apneas or hypopneas separated by the crescendo-decrescendo breathing pattern. Furthermore, the events must occur at a rate of five or more per hour during the monitoring period.
A less comprehensive, but useful, screening tool is overnight pulse oximetry. The device measures oxygen saturation in the blood and can detect the characteristic swings in oxygen levels that coincide with the periods of hyperventilation and apnea, providing an initial indication of the CSR pattern.
Clinical Management and Significance
The presence of Cheyne-Stokes Respiration is a significant finding associated with an impaired prognosis. The frequent apneas and resultant dips in blood oxygen levels can worsen heart function and lead to fragmented sleep, causing excessive daytime sleepiness and a reduced quality of life. Management focuses on two main strategies: optimizing the treatment of the underlying disease and providing direct respiratory support.
Optimizing the underlying condition, particularly heart failure, often involves medications to improve cardiac function. For direct respiratory support, Continuous Positive Airway Pressure (CPAP) is frequently used, which can stabilize the breathing pattern and improve the heart’s pumping ability in some patients.
Adaptive Servo-Ventilation (ASV) is a more advanced therapy providing variable pressure support that tracks and stabilizes the patient’s breathing. ASV is highly effective at suppressing the characteristic cycles and improving sleep quality more than CPAP in many cases. However, a large clinical trial raised concerns about the use of ASV in heart failure patients who have a severely reduced Left Ventricular Ejection Fraction (LVEF), leading some guidelines to recommend against its routine use in that specific population.