Chest
Volume 132, Issue 1, July 2007, Pages 81-87
Journal home page for Chest

ORIGINAL RESEARCH
SLEEP MEDICINE
The Significance and Outcome of Continuous Positive Airway Pressure-Related Central Sleep Apnea During Split-Night Sleep Studies

https://doi.org/10.1378/chest.06-2562Get rights and content

Objective:

To determine whether central sleep apnea (CSA) occurring during continuous positive airway pressure (CPAP) titration in patients with obstructive sleep apnea (OSA) reflects subclinical congestive heart failure (CHF), and whether these events will improve with CPAP therapy.

Design:

Cross-sectional analysis of patients with suspected sleep-related breathing disorders referred for split-night polysomnography

Patients and methods:

Forty-two OSA patients with and without CPAP-related CSA were analyzed. All CSA patients (n = 21) and control subjects (n = 21) underwent echocardiography, pulmonary function testing, and arterial blood gas (ABG) analysis. Repeat polysomnography with CPAP was performed 2 to 3 months after adequate CPAP therapy in CSA group patients.

Results:

Demographic, Epworth sleepiness scale, pulmonary function test, ABG, and baseline diagnostic polysomnography findings were similar in both groups. There was no difference in the prevalence of subclinical left ventricular systolic dysfunction in the CSA group vs the control group. CSA patients had decreased sleep efficiency (SE), increased sleep stage 1 percentage, sleep stages shift, wake time after sleep onset (WASO), and total arousals compared to control subjects. Twelve of 14 patients (92%) in the CSA group demonstrated complete or near-complete resolution of CSA events on follow-up polysomnography and showed improvement in SE, WASO, and total arousals compared to their baseline study.

Conclusions:

CSA events occurring during CPAP titration are transient and self-limited. They may be precipitated by the sleep fragmentation associated with initial CPAP titration and are not associated with an increased prevalence of occult CHF compared to OSA patients without CPAP-related CSA.

Section snippets

Patients

Patients were considered eligible for the study if they were ≥ 18 years old and seen from September 2004 through December 2005 with OSA identified using split-night polysomnography, and who also demonstrated CSA events exclusively during the CPAP titration portion of the sleep study (CSA group). CSA was defined as a CSA index (CSAI) ≥ 5/h. During CPAP titration, the pressure was raised only to eliminate obstructive and not central events. Subjects were excluded if they demonstrated CSA during

Results

A total of 116 patients with OSA who met criteria for a split-night study were evaluated. Twenty-three patients (19.8%) showed CSA events during CPAP titration. Two subjects with CPAP-related CSA were further excluded from the study because of an unsuccessful titration to eliminate obstructive events, leaving 21 subjects with CPAP-related CSA (CSA group; CSAI, 22.1 ± 13.8). These patients were compared to an equal number of control subjects (CSAI, 0.5 ± 0.9) identified by review of sleep logs

Discussion

CHF is associated with Cheyne-Stokes breathing during wakefulness and sleep. This type of respiration is quite distinct with a crescendo and decrescendo ventilatory pattern with an apnea or hypopnea at the nadir. Javaheri and Parker1 found that up to 45% of patients with CHF (LVEF ≤ 40%) had > 20 central apneas or hypopneas per hour of sleep.

CPAP therapy has been proven highly effective in treating OSA, leading to improvement in both subjective and objective daytime alertness as well as quality

References (32)

  • D Gozal

    Congenital central hypoventilation syndrome: an update

    Pediatr Pulmonol

    (1998)
  • KR Burgess et al.

    Central and obstructive sleep apnea during ascent to high altitude

    Respirology

    (2004)
  • DD Sin et al.

    Effects of continuous positive airway pressure on cardiovascular outcomes in heart failure patients with and without Cheyne-Stokes respiration

    Circulation

    (2000)
  • EEG arousals: scoring rules and examples; a preliminary report from the Sleep Disorders Atlas Task Force of the American Sleep Disorders Association

    Sleep

    (1992)
  • K Swedberg et al.

    Guidelines for the diagnosis and treatment of chronic heart failure: executive summary (update 2005): the Task Force for the Diagnosis and Treatment of Chronic Heart Failure of the European Society of Cardiology

    Eur Heart J

    (2005)
  • Cited by (0)

    The authors have no conflicts of interest to disclose.

    View full text