Central Sleep Apnea

What Is Central Sleep Apnea?

Central Sleep Apnea vs. Obstructive Sleep Apnea

The distinction below is a genuinely important one, not a technicality: it changes how central sleep apnea is diagnosed, what causes are considered, and how it is treated. Some patients have meaningful features of both, and mixed respiratory events, a single event with a central portion followed by an obstructive portion, are also recognized.

Obstructive Sleep Apnea vs. Central Sleep Apnea

Obstructive Sleep Apnea vs. Central Sleep Apnea

Dimension	Obstructive Sleep Apnea	Central Sleep Apnea
Primary Problem	The upper airway physically narrows or closes	The brain’s signal to breathe temporarily weakens or stops
Breathing Effort	Continues, and often increases, against the blocked airway	Pauses along with airflow, since the drive to try is what’s missing
Upper Airway	Narrowed or collapsed during the event	Stays open throughout the event
Snoring	A common, though not universal, clue	Not a typical feature, since the airway isn’t obstructed
Typical Associations	Excess weight, airway anatomy, sedatives, alcohol	Heart failure, opioid or sedative use, recent CPAP therapy, high altitude, certain neurological conditions
Diagnostic Testing	A home sleep apnea test is often an appropriate starting point	In-lab polysomnography is generally preferred to reliably measure breathing effort
Treatment Strategy	Keep the airway open: PAP therapy, oral appliances, weight management, or hypoglossal nerve stimulation	Address the underlying cause first, then PAP-based therapy, oxygen, medication, or phrenic nerve stimulation as appropriate

It is also worth being direct about overlap: having some central events on a sleep study does not automatically mean a person has a separate diagnosis to worry about, and having obstructive sleep apnea does not protect against central events appearing later, particularly once CPAP therapy begins. Distinguishing the two, and identifying when both are present, is precisely what a properly interpreted sleep study is for.

A Closer Look at the Major Causes

Central sleep apnea is not one single disease. It is a breathing pattern that can arise from several distinct underlying mechanisms (summarized above, in “What Causes Central Sleep Apnea?”), and identifying which one applies to a given patient is central to choosing the right treatment, not an academic exercise. The three most clinically important are worth explaining in more depth.

Heart failure and Cheyne-Stokes breathing. In heart failure, a combination of delayed circulation time and heightened sensitivity to carbon dioxide can make the breathing control system unstable. The result is often a distinctive pattern called Cheyne-Stokes breathing: breaths gradually build up in depth, then gradually fade away, with a central pause at the lowest point of the cycle, repeating every minute or so throughout parts of the night. Not everyone with central sleep apnea has heart failure, and not everyone with heart failure has central sleep apnea, but the two are seen together often enough that this pattern is specifically screened for in patients with reduced heart pumping function.

Opioids and other medications. Chronic opioid use can directly suppress the brainstem centers that generate breathing rhythm and blunt the body’s normal response to rising carbon dioxide. This tends to produce an irregular, rather than the smooth waxing-and-waning Cheyne-Stokes pattern, and is dose-related. It is a specific, recognized reason to evaluate breathing during sleep in a patient on long-term opioid therapy, alongside other symptoms.

High altitude. At altitude, lower oxygen levels drive faster breathing, which lowers carbon dioxide below the level needed to keep the drive to breathe stable during sleep, producing a periodic breathing pattern with central pauses. This is common even in healthy people at sufficient altitude and typically improves with acclimatization or upon returning to a lower elevation.

Treatment-Emergent Central Sleep Apnea

Treatment-emergent central sleep apnea, sometimes called complex sleep apnea, deserves its own explanation because it can be confusing for a patient who was just diagnosed with obstructive sleep apnea and started on CPAP. Central events can appear, or persist, once the obstructive events that prompted treatment are already being controlled by PAP therapy.

Why It Happens

Once the airway is no longer obstructed, an underlying instability in the breathing control system, which the obstruction may have been masking, can become apparent.

What Typically Happens Next

For many patients, this pattern improves on its own with continued, consistent PAP use over the following weeks as the system restabilizes.

A smaller number of patients have central events that remain frequent and clinically significant despite continued, well-fitted PAP therapy. That pattern is a reasonable trigger for the treating physician to reassess the approach, which may include adjusting therapy or considering an alternative such as adaptive servo-ventilation, discussed below. What a patient should not do is stop CPAP on their own because of this possibility; treatment-emergent central sleep apnea is something to bring to a follow-up visit, not a reason to discontinue therapy independently.

How Central Sleep Apnea Is Diagnosed

The Diagnostic Pathway

1. 01→Symptoms or ConcernWitnessed breathing pauses, unexplained fatigue, or a relevant medical history prompts evaluation.↓
2. 02→Clinical HistoryA physician reviews cardiac, neurological, medication, and altitude history alongside symptoms.↓
3. 03→Testing DecisionGiven that history, your physician determines whether an in-lab study is preferred over a home test.↓
4. 04Sleep StudyThe study measures airflow, breathing effort, oxygen levels, and, for an in-lab study, sleep stage directly.↓
5. 05→Event ClassificationA physician distinguishes central from obstructive (and mixed) events using the effort signal specifically.↓
6. 06→Cause EvaluationFindings are considered alongside your cardiac, medication, and neurological context to identify a likely cause.↓
7. 07Personalized TreatmentTreatment is planned around that specific cause, together with you and your physician.

Can a Home Sleep Test Diagnose Central Sleep Apnea?

Generally, not reliably, and this is an important limitation to understand before scheduling one. Most home sleep apnea test devices are built to measure airflow and estimate breathing effort indirectly; they were designed and validated for straightforward obstructive sleep apnea, not for distinguishing a central event, where effort is genuinely absent, from an obstructive one, where effort continues. A home test can therefore understate or entirely miss central sleep apnea.

Current sleep medicine guidance is specific about this. Rather than home testing, in-lab polysomnography is called for when there is significant cardiorespiratory disease, suspected central sleep apnea or another non-obstructive breathing pattern, possible respiratory muscle weakness, chronic opioid use, a history of stroke, or awake hypoventilation is suspected. In practice, this means most patients with a reasonable clinical suspicion for central sleep apnea, particularly anyone with known heart failure, chronic opioid use, or a prior stroke, are better served starting with an in-lab study rather than a home test.

Understanding Your Sleep-Study Results

These numbers are a starting point for a physician’s interpretation, not a self-contained diagnosis or treatment plan on their own; how they’re read always sits alongside your broader medical history.

How Is Central Sleep Apnea Treated?

The starting principle is straightforward to state and genuinely important in practice: treatment depends on why central sleep apnea is occurring, not on applying one default approach to every patient. A physician weighs the underlying cause, symptom burden, the sleep-study pattern, cardiovascular status, any relevant medication exposure, and, where applicable, how a patient has already responded to PAP therapy.

For heart failure-associated central sleep apnea in particular, optimizing treatment of the heart failure itself is a foundational part of the plan, not a separate track from sleep-specific therapy.

CPAP

Often a reasonable starting point across CSA causes, including heart failure-associated CSA, though central events that persist despite consistent use are a reason to consider an alternative.

Bilevel PAP With a Backup Rate

Delivers a minimum breath rate even if the patient’s own drive briefly lapses; generally considered outside heart failure-associated CSA.

Adaptive Servo-Ventilation (ASV)

A therapy purpose-built for unstable breathing patterns; patient selection, including cardiac history, matters. Discussed in its own section below.

Low-Flow Oxygen

An option particularly for heart failure-associated CSA and high-altitude periodic breathing.

Acetazolamide

An oral medication that can help stabilize breathing control; an option across several CSA causes, including altitude.

Transvenous Phrenic Nerve Stimulation

An implanted therapy considered after other approaches haven’t adequately worked. Discussed in its own section below.

One safety point is worth stating plainly: bilevel PAP used without a backup breathing rate is not an appropriate substitute for the options above. Without that backup rate, it can actually provoke or worsen central breathing pauses rather than help them, so this is specifically a device and settings decision for your physician, not something to adjust on your own.

Current guidance from the American Academy of Sleep Medicine describes every one of the treatment options above as a conditional recommendation, meaning they are reasonable, evidence-supported options for the right patient, not a single mandated protocol applied uniformly. This is a genuine reflection of the current evidence, not a gap in this summary.

Adaptive Servo-Ventilation (ASV)

Adaptive servo-ventilation is a PAP-based therapy purpose-built for central sleep apnea’s unstable breathing pattern, rather than for a physically obstructed airway.

What It Does

Continuously adjusts the level of breathing support, breath by breath, to smooth out a waxing-and-waning breathing pattern like Cheyne-Stokes breathing, aiming to stabilize overall ventilation.

How It Differs From CPAP

CPAP delivers a steady or auto-adjusting pressure mainly to keep the airway physically open. ASV instead targets a moving breathing pattern itself, delivering more support during a shallow phase and less during a fuller one.

Why patient selection, and cardiac history specifically, matters. ASV’s role in heart failure-associated central sleep apnea has a genuinely important history that is worth explaining honestly rather than glossing over. A 2015 clinical trial found that one specific ASV device was associated with increased mortality in patients with heart failure with reduced pumping function (reduced ejection fraction) and predominantly central sleep apnea; that particular device is no longer manufactured. More recent trial evidence, using a different device with a different underlying algorithm, has not reproduced that mortality signal in a similar heart failure population. Current sleep medicine guidance reflects this more nuanced picture: ASV remains a reasonable, individualized option across central sleep apnea causes, including heart failure-associated CSA, rather than a therapy that is uniformly avoided in heart failure, but it also makes clear that different ASV devices use different proprietary algorithms and that safety evidence is not equally established for every device on the market. In practice, this means ASV candidacy, and which specific device is used, is determined individually, with real attention to cardiac history, not from a blanket rule in either direction.

Phrenic Nerve Stimulation

Transvenous phrenic nerve stimulation is an implanted therapy for central sleep apnea, most often considered for heart failure-associated or primary central sleep apnea once other therapies have not adequately worked.

The Concept

A small device is implanted, similar in concept to a cardiac device, with a lead placed near the phrenic nerve, which controls the diaphragm.

How It Works

The device senses the normal breathing cycle and delivers a mild electrical stimulation at the right point in that cycle, prompting a diaphragm contraction to help restore a more regular breath during sleep.

Who May Be Considered

Patients whose central sleep apnea has not adequately responded to other therapies, ideally with few or no obstructive events, since this therapy does not address airway obstruction.

This is an implanted surgical therapy, involving a procedure, a healing period, and device follow-up, and it is considered for selected patients rather than as a routine or first-line treatment for central sleep apnea generally. It was first FDA approved in 2017, with an updated system approved more recently. VitalAir is not affiliated with any device manufacturer; candidacy is determined entirely through individual clinical evaluation.

Central Sleep Apnea Care at VitalAir

Sleep testing and a PAP therapy follow-up plan are both part of how VitalAir works through a suspected central sleep apnea evaluation; patients already on PAP therapy who are troubleshooting persistent symptoms may also find this guide to common PAP therapy issues useful for the more common, comfort-related causes of poor sleep on treatment before assuming the cause is central sleep apnea itself.

VitalAir evaluates and manages central sleep apnea for patients across Frisco, North Dallas, and the broader North Texas area. Because central sleep apnea is so often tied to another underlying condition, that evaluation typically integrates a detailed sleep history, review of any previous sleep studies, PAP download data when a patient is already on therapy, a medication review, and relevant cardiovascular or pulmonary context, alongside in-lab sleep testing when appropriate. Treatment, including PAP-based therapy or more advanced ventilation strategies, is planned individually around the specific cause identified. The clinical information on this page applies to patients everywhere; what differs locally is simply where that evaluation and follow-up care happens.