From the Guidelines
Central sleep apnea (CSA) is primarily caused by underlying conditions such as heart failure, Prader-Willi syndrome, and other factors that affect ventilatory control.
Causes of Central Sleep Apnea
- Heart failure: CSA is commonly associated with heart failure, particularly heart failure with reduced ejection fraction (HFrEF) 1. The severity of heart failure is paralleled by the CSA apnea-hypopnea index (AHI).
- Prader-Willi syndrome: Individuals with Prader-Willi syndrome are at increased risk of developing CSA, especially infants, with a reported prevalence of 43% 1. Poor ventilatory control and scoliosis or other spinal abnormalities may contribute to CSA in this population.
- Other factors: Additional factors that may contribute to CSA include pulmonary venous congestion, increased sympathetic activity, loss of endothelial nitric oxide activity in the carotid bodies, and increased physiological pulmonary dead space 1.
Key Characteristics of CSA
- CSA is characterized by an oscillatory pattern of respiration associated with cyclic changes in blood pressure, heart rate, and sleep 1.
- It occurs during stage N1 and N2 sleep when ventilation is under "chemical control" (i.e., the partial pressure of carbon dioxide) and rarely in stage N3 or R sleep 1.
- CSA can be predicted by abnormal markers of cardiac, autonomic, and pulmonary function, such as low left ventricular ejection fraction (LVEF), high pulmonary capillary wedge pressure (PCWP), and high brain natriuretic peptide 1.
From the Research
Causes of Central Sleep Apnea (CSA)
The causes of central sleep apnea (CSA) can be classified into several categories, including:
- Primary or idiopathic CSA, which is a rare form of the condition 2, 3
- Cheyne-Stokes respiration, characterized by periodic CSA and a crescendo/decrescendo breathing pattern, often in patients with severe cardiac or neurological diseases 2, 4, 3
- High altitude-induced periodic breathing, which occurs at high altitudes (above 4000 m) 2, 3
- CSA due to medical or neurological conditions, such as chronic renal failure, stroke, or brainstem damage 5, 6, 3
- CSA due to drug or substance use, such as opioid use 2, 6, 3
- Primary sleep apnea of infancy 3
Underlying Mechanisms
The underlying mechanisms of CSA include:
- Unstable ventilatory control during sleep, which can lead to repetitive periods of insufficient ventilation and compromised gas exchange 2
- Loss of the wakefulness drive to breathe, which can lead to a rise in P(aCO(2)) at the onset of sleep 4
- Abnormalities in the breathing control system, such as diminished carbon dioxide response curves 5
- Neurological diseases affecting the brainstem, which can produce breathing pattern disorders in sleep 5