[Oxygen saturation and sleep structure in patients with dilated cardiomyopathy]

It is known that patients suffering from severe cardiomyopathy may develop cyclic changes in breathing (Cheyne-Stokes-breathing) (2, 3). Coughing and dyspnea may be linked to periodic breathing. Specific detailed polysomnographic studies of sleep architecture and oxygen saturation have not been published. Eight patients suffering from dilatative cardiomyopathy (NYHA III-IV) were studied by pulse oximetry and polysomnography. Six of eight patients had severe breathing irregularities. These disturbances became manifest partially as Cheyne-Stokes breathing, partially as central sleep apnea. During these periods, oxygen saturation dropped as far as to 65 per cent of the original level.