Electrocardiogram recording as a screening tool for sleep disordered breathing

Study Objectives: Transient changes in heart rate associated with obstructive apneas have been suggested for screening of sleep disordered breathing (SDB). This study prospectively compares the outcomes of an automated ECG-based SDB screening tool with simultaneous polysomnography. Methods: The previously-developed automated algorithm was applied to a single channel ECG obtained during standard overnight polysomnography (92 subjects) to obtain an apnea-hypopnea index (AHI) estimate. Using AHI thresholds of <5 and ≥15 to define absence and presence of SDB, respectively, we determined the likelihood ratios of the proposed technique. Results: The automated algorithm achieved positive and negative likelihood ratios of 2.16 and 0.08. Estimated and reference AHI were highly correlated (r = 0.88). Pathologically insignificant arrhythmia in some subjects had no discernible impact on the algorithm. Conclusions: ECG-based assessment provides a simple but limited means of recognizing subjects with obstructive sleep apnea.