Cheyne Stokes respiration (CSR) is a crescendo-decrescendo pattern of respiration followed by central apnea (lack of breathing) or hypopnea (shallow breathing). Episodes may last as long as 30 seconds.
The term crescendo-decrescendo does not refer to loudness but rather to the frequency and depth of the breaths. During crescendo, the patient's breaths become more frequent and deeper while during descrescendo, they become less frequent and shallower. The episode will culminate in a period of apnea or hypopnea.
It is seen in normal people at high altitude, but at sea level, it is seen in patients with
decreased lung volume
decreased metabolic rate
cerebral vascular disease
In addition, twenty-five percent (25%) of patients who have Congestive Heart Failure (CHF) will have Cheyne-Stokes respiration.