Apnea detection from 24-hour recordings of respiration in chronic heart failure patients

Patients with heart failure may present periodic breathing and Cheyne-Stokes respiration during polygraphic laboratory monitoring. Free-living 24-hour respiratory ambulatory recording should improve detection of abnormal breathing pattern. To test this hypothesis 32 heart failure patients underwent both 20-minute laboratory short-term recording and long-term ambulatory recording of ECG and respiratory signal. Automatic apnea identification has been performed by a technique based on amplitude demodulation of a filtered and enhanced respiratory signal. Automatic detection was effective for the identification of apneas/hypopneas both at day- and nighttime; long-term recordings showed an improved diagnostic accuracy as compared to short-term ones.