abraham_Cardiology_book_temp 26/10/2009 17:15 Page 72
Heart Failure
Central Sleep Apnea in Heart Failure
Rami Khayat, MD, FACCP,
1,2
Andrew Pederzoli, MD
3
and William Abraham, MD, FACC
1,4
1. The Ohio State University Sleep–Heart Program; 2. Division of Pulmonary, Allergy, Critical Care, and Sleep;
3. Department of Medicine; 4. Division of Cardiovascular Medicine, Ohio State University
Abstract
Central sleep apnea (CSA) is a manifestation of respiratory control instability in patients with heart failure. While recent evidence suggests a
decrease in its prevalence in patients with heart failure, CSA remains a relatively common disorder in this population. CSA worsens the
prognosis of patients with systolic dysfunction. Due to their overlapping risk factors and mechanisms in patients with systolic dysfunction, both
obstructive sleep apnea and CSA can co-exist in the same patient. This renders the distinction between obstructive and central disorders of
sleep artificial. The clinician caring for patients with heart failure must therefore be cognizant of this overlap and maintain a comprehensive
approach to the management of sleep-disordered breathing in this complicated setting. In this article, the mechanisms and prevalence of CSA
in heart failure are briefly presented. The discussion focuses on the cardiovascular consequences of CSA in patients with heart failure.
Keywords
Central sleep apnea (CSA), Cheyne-Stokes respiration (CSR), sleep-disordered breathing (SDB), heart failure
Disclosure: The authors have no conflicts of interest to declare.
Received: August 5, 2009 Accepted: September 16, 2009
Correspondence: Rami Khayat, MD, FACCP, The Ohio State University Sleep–Heart Program, Room 201, DHLRI, 473 West 12th Avenue, Columbus, OH 43210.
E: Rami.Khayat@osumc.edu
Heart failure is the only cardiovascular disease with increasing the manifestation of respiratory control instability in heart failure. An
incidence and mortality.
1
Approximately  five million Americans have oscillatory pattern of respiration was first described in patients with heart
heart failure, with an annual incidence of 10 per 1,000 in individuals failure, along with stroke and morbid obesity, well over two centuries ago
over 65 years of age, an already rising demographic segment of society. by Cheyne, followed by Stokes. Cheyne-Stokes respiration (CSR) is an
Heart failure is the most frequent Medicare diagnosis, with most of its oscillatory breathing pattern characterized by recurring 60–90-second
cost related to hospitalizations.
1,2
Identification and treatment of highly cycles of gradually increasing ventilation (crescendo). This is followed by
prevalent comorbidities with known detrimental effects, such as sleep- a gradual decrease in ventilation (decrescendo) that culminates in a
disordered breathing (SDB), carries a high potential for positive impact.
3
visually recognizable prolonged apnea or hypopnea (see Figure 1). CSR is
SDB is broadly divided into two main syndromes: obstructive sleep a morphological pattern of ventilation that can occur during restful
apnea (OSA) and central sleep apnea (CSA). Both syndromes of SDB wakefulness and exercise in patients with heart failure
6,13
as well as
are increasingly recognized as contributors to cardiovascular morbidity during sleep. As polygraphic recording of sleep (polysomnography) was
and mortality. OSA is a cause of hypertension and a risk factor for developed in the 1960s, the first polysomnographic description of
coronary artery disease, arrhythmia, and cardiovascular mortality.
4
CSR was made in 1965.
14
The diagnosis of CSA is made based on
Thus, OSA is highly prevalent in patients with end-stage heart disease.
5
clinical polysomnography (sleep study) and takes into account only
A rare form of SDB in the general population, CSA is a consequence of the presence of central apnea or hypopnea and not necessarily the
respiratory control instability in patients with severe heart failure, and it presence of the oscillatory pattern of ventilation. Generally, patients
worsens the prognosis of the underlying heart failure.
6–8
SDB in both with heart failure and CSA will have the CSR pattern with central apneas,
obstructive and central forms is present in over 60% of patients with and the disorder is sometimes termed CSA-CSR. For purposes of clarity,
heart failure and is largely undiagnosed.
5,9,10
Treatment of both CSA and CSA is the polysomnographically diagnosed SDB with predominantly
OSA is safe, effective, and well tolerated, and can improve the central apneas, while CSR is the oscillatory breathing pattern that is
underlying heart failure as well as quality of life.
11,12
visually recognized and can be present during sleep as well as
wakefulness. When CSR occurs during restful wakefulness or exercise,
Definitions it obviously cannot be termed central  ‘sleep’ apnea and is referred
Before proceeding with this review, it is critical to clarify the to as CSR only. Therefore, both terms describe the same underlying
nomenclature that has evolved over the past 200 years to describe respiratory control instability.
72 © TOUCH BRIEFINGS 2009