Can Respiratory Sleep Disorders Signal Advanced Heart Failure?

SEPTEMBER 20, 2015
Jeannette Y. Wick, RPh, MBA, FASCP
Although respiratory sleep disorders occur in up to half of all congestive heart failure (CHF) cases, they remain underdiagnosed in CHF.

One case report recently published in the Journal of Thoracic Disease describes the benefits of addressing respiratory sleep disorders in heart failure patients.

According to the author, these disorders can be separated into 2 categories:

·         Obstructive sleep apnea (OSA), in which the airway collapses during sleep.
·         Central sleep apnea (CSA), which is a response to elevated carbon dioxide levels.

OSA causes heart failure through relative hypertension during sleep. But CSA is a heart failure sequela because maladaptive Cheyne-Stokes respiration decreases carbon dioxide levels in the setting of heart failure hypercapnia.

A variant of continuous positive airway pressure (CPAP) known as adaptive servo-ventilation (ASV) therapy is effective at maintaining normal breathing patterns during Cheyne-Stokes respiration.

The author conducted a sleep study on a 68-year-old former smoker with a history of myocardial infarction, atrial fibrillation, pulmonary edema, and pacemaker placement. The patient had a 10-year snore history, an Epworth Sleepiness Scale score of 7 (normal is under 10), and New York Heart Association class III heart failure awaiting a heart transplant at hospitalization.

The patient had CSA during non-rapid eye movement (REM) sleep and OSA during REM sleep with borderline low partial pressure of carbon dioxide (pCO2) levels (37 mmHg) throughout the night when he was not using CPAP.

While on CPAP, the patient’s peripheral capillary oxygen saturation (SpO2) improved (70% to 89%). He also slept more soundly, as measured by increased time in a supine position and slow wave brain activity.

Most importantly, the patient’s objective and subjective heart failure symptoms improved.

This case report shows that respiratory support may greatly improve heart failure symptoms, sparing the patient from therapy escalation such as heart transplant.

Because CSA is an indication of severe CHF with pulmonary edema, it may act as a signal that the underlying heart failure needs to be better addressed.