This topic was
reviewed in JACC. The full text is only available to
subscribers but the audio summary is open access.
Here are a few
points of interest:
Obstructive sleep
apnea (OSA) is common in the general population.
Central sleep apnea
(CSA) is largely confined to patients who already have cardiovascular
disease, largely heart failure. It is particularly associated with
heart failure with reduced ejection fraction. It is also associated
with stroke and atrial fibrillation.
OSA is a cause of
multiple cardiovascular disorders. CSA, though a result of certain
cardiovascular disorders, can in turn contribute to further
cardiovascular dysfunction, resulting in a vicious cycle of
reciprocal cause and effect.
Although OSA is
largely a disorder of obesity, in which fatty deposits in the upper
airway are contributory, 20-30% of OSA is in non-obese individuals.
In such cases upper airway dilator muscle dysfunction is believed to
be at play.
Among the many
consequences of sleep apnea are the metabolic effects of hypoxemia,
increased sympathetic output, cytokine activation, endothelial
dysfunction, insulin resistance, systemic and pulmonary hypertension
and atrial fibrillation.
Treatment of OSA
with CPAP ameliorates many of these, though treatment of CSA with positive pressure modalities has been disappointing and may be detrimental.
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