Cheyne-Stokes respiration is an abnormal breathing pattern defined by periods of tachypnea and hyperpnea (in a crescendo-decresendo pattern) that alternate with periods of apnea. These cycles of increasing and decreasing breathing activity ordinarily last from 30 seconds to two minutes in duration, with 5-30 seconds of apnea.
It is commonly associated with decompensated heart failure and neurologic diseases (including stroke), in which the ventilatory patterns may not be recognized as the clinical features are dominated by the underlying disease process.
Cheyne-Stokes respiration may yield significant systemic effects including changes in mental status (as in our case today), oxygen desaturation, increased pulmonary vascular pressures, arrhythmias, and stimulation of the sympathetic nervous system. Based upon small case series, patients with congestive heart failure and Cheyne-Stokes respiration have a significantly greater mortality.
Treatment of Cheyne-Stokes respiration in the setting of CHF (based on current and evolving evidence) is primarily optimal medical therapy directed at congestive heart failure, followed by CPAP (commenced gradually under supervision; with caution given the increased mortality with adaptive seroventilation observed in the 2015 SERVE-HF trial), and/or supplemental oxygen.
See this nice review from BMJ Thorax for more info on the pathophysiology and treatment.