Cheyne-Stokes respiration screening using cyclic variation in heart rate detected by Holter electrocardiogram

BACKGROUND: Cheyne-Stokes respiration (CSR) is a major form of central sleep apnea in patients with heart failure and is associated with mortality in these patients. Although full polysomnography is required for CSR diagnosis, access may be limited. Cyclic variation of heart rate (CVHR) detected by Holter electrocardiogram reflects changes in cardiac autonomic activity associated with apnea-hypopnea events and is easier to perform than polysomnography. METHODS: We examined whether RR interval shortening time in the CVHR analysis could be useful for screening CSR. In this study, 41 patients were analyzed. Holter electrocardiogram and polysomnography were simultaneously performed. CVHR events were classified as CSR or not based on RR interval shortening time, and the percentage of CSR (%CSR), defined as the ratio of total CSR duration to time in bed, was measured. RESULTS: There were 27 patients with heart failure. The patients tended to have severe sleep-disordered breathing and an apnea-hypopnea index of 38.9 (24.7), and seven patients had predominantly central events. Based on %CSR determined by polysomnography with manual scoring ≧20%, 10 patients were labeled as CSR-positive and 31 as CSR-negative. There was moderate-to-good reliability between the percentage of CSR determined via CVHR analysis and the percentage of CSR determined via polysomnography [intraclass correlation coefficient = 0.74 (0.56, 0.85); p < 0.001]. CONCLUSIONS: Holter electrocardiograms are performed for many patients with heart failure and are better tolerated than overnight polysomnography. Our method of using CVHR detected by Holter electrocardiogram could be helpful for CSR screening.