Al Ashry HS, Thomas RJ, Hilmisson H. A Combination Index of Low Frequency Cardio-Pulmonary -Coupling and Oxygen Desaturation has a Strong Correlation with the Apnea Hypopnea Index. Sleep 2019; 42(Suppl_1). A188. DOI: 10.1093/sleep/zsz067.466
Cardiopulmonary coupling (CPC) is an ECG-based analysis incorporating cyclic variation in heart rate (CVHR) typical of apnea, and ECG-derived respiration, to generate sleep apnea metrics. Elevated Low Frequency Coupling (e-LFC) is a CPC pattern that has been associated with fragmented sleep. Narrow spectral band e-LFC (e-LFC-NB) associates with sustained central apnea, classic periodic breathing, and high loop gain obstructive sleep apnea OSA). Broad spectral band e-LFC (e-LFC-BB) associates with OSA. To observe accuracy of an AHI derived from limited measurements to enable simple sleep apnea diagnosis we combined e-LFC with oxygen desaturations to generate a SleepImage-AHI (SAHI) index and examined its correlation with the conventional 3%/arousal AHI using polysomnograms.
Combining CPC and ODI yields a metric comparable to AHI3%/arousal on PSGs.
This approach to measure AHI to diagnose sleep apnea offers simple, low-cost and easily scalable method for sleep disorder management.