Utility of cyclic variation of heart rate score as a screening tool for sleep-disordered breathing in patients with heart failure.

STUDY OBJECTIVES Patients with sleep-disordered breathing (SDB) have cyclic variation of heart rate (CVHR) in response to respiratory events. However, limited data are available regarding the utility of CVHR as a screening tool for SDB in mixed heart failure (HF) and non-HF patients. METHODS We enrolled consecutive patients with and without HF who underwent full polysomnographies with simultaneous Holter electrocardiogram monitoring. We determined the temporal position of the individual dips comprising the CVHR score using time-domain methods. RESULTS The data of 101 patients, including 70 with and 31 without HF, were analyzed. The CVHR score was significantly correlated with the apnea-hypopnea index (AHI) (r = 0.667, P < 0.001) and limits of agreement between the AHI and CVHR score were -21.8 to 35.2. The receiver operating characteristic analysis demonstrated that the CVHR score (best cut-off of 23.5 events/h) identified severe SDB with a sensitivity of 83.3%, specificity of 79.5%, and the area under the curve of 0.856. In addition, there was no interaction between the presence or absence of HF and the AHI-CVHR score relationship (P = 0.323). CONCLUSIONS The CVHR score, determined by Holter electrocardiogram monitoring, is a useful tool for evaluating SDB even in mixed HF and non-HF patients.