Clinical and Academic Department of Sleep and Breathing, National Heart and Lung Institute and NIHR Biomedical Research Unit, Royal Brompton Hospital and Imperial College, London, UK.
Thorax. 2012 Nov;67(11):1000-5. doi: 10.1136/thoraxjnl-2012-201684. Epub 2012 Jul 17.
Sleep-disordered breathing (SDB) is under diagnosed in chronic heart failure (CHF). Screening with simple monitors may increase detection of SDB in a cardiology setting. This study aimed to evaluate the accuracy of heart rate variability analysis and overnight pulse oximetry for diagnosis of SDB in patients with CHF.
180 patients with CHF underwent simultaneous polysomnography, ambulatory electrocardiography and wrist-worn overnight pulse oximetry. SDB was defined as an apnoea-hypopnoea index ≥15/h. To identify SDB from the screening tests, the per cent very low frequency increment (%VLFI) component of heart rate variability was measured with a pre-specified cutoff ≥2.23%, and the 3% oxygen desaturation index was measured with a pre-specified cutoff >7.5 desaturations/h.
173 patients with CHF had adequate sleep study data; SDB occurred in 77 (45%) patients. Heart rate variability was measurable in 78 (45%) patients with area under the %VLFI receiver operating characteristic curve of 0.50. At the ≥2.23% cutoff, %VLFI sensitivity was 58% and specificity was 48%. The 3% oxygen desaturation index was measurable in 171 (99%) patients with area under the curve of 0.92. At the pre-specified cutoff of >7.5 desaturations/h, the 3% oxygen desaturation index had a sensitivity of 97%, specificity of 32%, negative likelihood ratio of 0.08 and positive likelihood ratio of 1.42. Diagnostic accuracy was increased using a cutoff of 12.5 desaturations/h, with sensitivity of 93% and specificity of 73%.
The high sensitivity and low negative likelihood ratio of the 3% oxygen desaturation index indicates that pulse oximetry would be of use as a simple screening test to rule out SDB in patients with CHF in a cardiology setting. The %VLFI component of heart rate variability is not suitable for detection of SDB in CHF.
睡眠呼吸障碍（SDB）在慢性心力衰竭（CHF）中诊断不足。使用简单的监测器进行筛查可能会增加在心脏病学环境中检测 SDB 的机会。本研究旨在评估心率变异性分析和夜间脉搏血氧饱和度监测在 CHF 患者中诊断 SDB 的准确性。
180 例 CHF 患者同时进行多导睡眠图、动态心电图和腕戴式夜间脉搏血氧饱和度监测。SDB 的定义为呼吸暂停低通气指数≥15/h。为了从筛查试验中识别 SDB，使用预先指定的截断值≥2.23%测量心率变异性的非常低频成分（%VLFI），并使用预先指定的截断值>7.5 次/小时测量 3%氧减饱和度指数。
173 例 CHF 患者有足够的睡眠研究数据；77 例（45%）患者发生 SDB。可测量心率变异性的 78 例（45%）患者，%VLFI 的受试者工作特征曲线下面积为 0.50。在≥2.23%的截断值下，%VLFI 的灵敏度为 58%，特异性为 48%。171 例（99%）患者可测量 3%氧减饱和度指数，曲线下面积为 0.92。在预先指定的>7.5 次/小时的截断值下，3%氧减饱和度指数的灵敏度为 97%，特异性为 32%，阴性似然比为 0.08，阳性似然比为 1.42。使用 12.5 次/小时的截断值，诊断准确性提高，灵敏度为 93%，特异性为 73%。
3%氧减饱和度指数的高灵敏度和低阴性似然比表明，脉搏血氧饱和度监测可能作为一种简单的筛查试验，用于排除心脏病学环境中 CHF 患者的 SDB。心率变异性的%VLFI 成分不适合检测 CHF 中的 SDB。
