Abstract 9391: Cyclic Variation of Heart Rate Score by Holter ECG for screening Sleep Disordered Breathing in Heart Failure Patients

Abstract

Background: Sleep disordered breathing (SDB) has a critical association with cardiovascular mortality and morbidity, especially in patients with heart failure (HF). However, because of the complexity to refer the polysomnography, the majority of SDB patients remain undiagnosed. On the other hand, the abnormality of heart rate variability has been reported in patients with SDB. To explore an efficient ECG-based screening tool for SDB, we examined the usefulness of cyclic variation of heart rate score (CVHRS) by Holter ECG in HF patients. Methods and Results: In this study, 110 patients with HF (mean age 58.6 years, body mass index 23.6, left ventricular ejection fraction 45.5%) were enrolled. The exclusion criteria were the presence of atrial fibrillation and receiving implantable pacemaker device therapy. We simultaneously performed Holter ECG and polysomnography in night time, and measured apnea-hypopnea index (AHI) and CVHRS. We determined the temporal position of the individual dips comprising the CVHRS, using time-domain methods. CVHRS was measured as cyclic and auto correlated dips in smoothed interbeat interval time series. There were 77 patients with mild to moderate SDB (5≤AHI<30/h) and 26 patients with severe SDB (AHI ≥30/h). There was a significant positive correlation between CVHRS and AHI (R=0.60, P<0.001). From the ROC analysis, CVHRS (a cut off value of 30) identified severe SDB with sensitivity 82%, specificity 77%, positive predictive value (PPV) 78%, negative predictive value (NPV) 81% and area under the curve (AUC) 0.83. Conclusions: CVHRS determined by Holter ECG is a useful screening index for severe SDB in HF patients.