Central sleep apnea (CSA) causes temporary stoppages of breathing because a person lacks respiratory effort i.e. the muscles responsible for breathing are not activated and breathing does not occur. It occurs when the brain does not send signals to the muscles responsible for breathing. Unlike obstructive sleep apnea symptoms where the patient often struggles for air, in CSA no struggle occurs. Left untreated, central sleep apnea can cause seizures, heart attacks and even death. Of the three types of sleep apnea, central sleep apnea is the least common, only occurring in about 4% – 5% of cases.

Causes of Central Sleep Apnea

There are several different conditions that can cause or contribute to central sleep apnea symptoms. The area of our brain that controls breathing functions is located in the brain stem. Normally, our autonomic nervous system “automatically” triggers our diaphragm to contract and initiate breathing when there is a build up of carbon dioxide in our blood.  Any condition that either interferes with our brain stem’s ability to function such as injury, disease or medication can initiate CSA symptoms. CSA can be caused by many factors including high altitude (low oxygen levels), certain neurological conditions like Parkinson’s disease, encephalitis or brain stem injuries and most commonly by congestive heart failure. Other conditions such as bulbar poliomyelitis, primary hypoventilation syndrome and severe obesity and damage to the cervical spine can also contribute to central sleep apnea. Certain medicines such as painkillers containing narcotic drugs can lead to central sleep apnea as well.

Central sleep apnea is characterized by the following signs and symptoms:

  • Episodes of stopped breathing
  • Difficulty staying asleep
  • Restless sleep
  • Excessive daytime sleepiness
  • Fatigue
  • Shortness of breath
  • Snoring
  • Difficulty concentrating

As previously noted, central sleep apnea is most commonly associated with heart disease, specifically congestive heart failure. Medical experts suggest that about 40% to 60% of all patients with CHF also have central sleep apnea. CSA in patients with congestive heart failure is manifested by what’s known as Cheyne-Stokes respirations, first documented by 19th century physicians John Cheyne and William Stokes. During a Cheyne-Stokes breathing episode, breathing  is rapid followed by a period of slower breathing or apnea. These breathing cycles occur over and over as the brain tries to maintain normal oxygen and carbon dioxide levels in the blood. Cheyne-Stokes can occur day or night but is more pronounced while sleeping. While CSA is thought to be caused by congestive heart failure, CSA can itself also contribute to additional heart failure creating a vicious cycle. 

Central Sleep Apnea Treatment

Since CSA is caused by such a wide variety of factors, treatment varies depending on the cause. Oftentimes, CSA is best treated by treating the underlying causative factor. So, if the cause of central sleep apnea is low oxygen levels at high altitude, then the solution is supplemental oxygen or moving to a lower altitude. Since the majority of CSA cases are associated with heart failure, I will focus there.

Central sleep apnea in patients with CHF is usually treated by addressing the cause of the underlying heart failure. When a person is experiencing heart failure, their body retains extra fluid due to the reduced functioning of their heart. Since the heart isn’t strong enough to pump blood throughout the body, extra fluid builds up in the lungs, liver and extremities like the arms and legs. This reduces the oxygen levels in those areas and they can be damaged. Heart medications such as ACE Inhibitors can help dilate the blood vessels and reduce the heart’s workload. Beta-blockers are used to slow down your heart and help improve blood flow. Diuretics can also help by increasing the rate that our bodies eliminate excess  fluid through diuresis.

Additionally, any steps that can be taken to help the heart can also help reduce or eliminate the symptoms of central sleep apnea. As with obstructive sleep apnea, weight loss is often beneficial for central sleep apnea. Smoking cessation has been shown to help the heart and lungs function more effectively and reduce incidences of central sleep apnea. A study conducted in Japan showed that patients with heart failure who participated in a 6 month cardiac rehabilitation exercise program showed reduced incidences in their CSA symptoms.

Finally, sleep apnea machines like CPAP and BIPAP have proven to be very effective for treating central sleep apnea as well as OSA.  They can significantly reduce apnea episodes.

Central sleep apnea is a serious medical condition, especially when combined with other significant medical complications such as heart failure. However, treatment is available. Given the strong association between central sleep apnea and heart failure, if you have been diagnosed with CHF, ask you doctor if you should be tested at a sleep apnea clinic to see if you have central sleep apnea too.

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