Gilman Matthew P, Floras John S, Usui Kengo, Kaneko Yasuyuki, Leung Richard S T, Bradley T Douglas
Sleep and Cardiovascular Physiology Research Laboratories, Mount Sinai Hospital, Toronto, ON, Canada.
Clin Sci (Lond). 2008 Feb;114(3):243-9. doi: 10.1042/CS20070172.
Patients with heart failure or OSA (obstructive sleep apnoea) have reduced HF-HRV (high-frequency heart rate variability), indicating reduced cardiac vagal modulation, a marker of poor prognosis. CPAP (continuous positive airway pressure) abolishes OSA in patients with heart failure, but effects on daytime HF-HRV have not been determined. We hypothesized that, in patients with heart failure, treatment of coexisting OSA by CPAP would increase morning HF-HRV. In 19 patients with heart failure (left ventricular ejection fraction <45%) and OSA (>/=20 apnoeas and hypopnoeas/h of sleep), HF-HRV was quantified before and 1 month after randomization to a control or CPAP-treated group. In the control group (n=7), there were no changes in HF-HRV over the 1 month study during wakefulness in the morning. In the CPAP-treated group (n=12) HF-HRV increased significantly during wakefulness in the morning [from 2.43+/-0.55 to 2.82+/-0.50 log(ms(2)/Hz); P=0.002] due to an increase in transfer function between changes in lung volume and changes in HF-HRV (92.37+/-96.03 to 219.07+/-177.14 ms/l; P=0.01). In conclusion, treatment of coexisting OSA by nocturnal CPAP in patients with heart failure increases HF-HRV during morning wakefulness, indicating improved vagal modulation of heart rate. This may contribute to improved prognosis.
心力衰竭或阻塞性睡眠呼吸暂停（OSA）患者的高频心率变异性（HF-HRV）降低，这表明心脏迷走神经调节功能减弱，是预后不良的一个指标。持续气道正压通气（CPAP）可消除心力衰竭患者的OSA，但对日间HF-HRV的影响尚未确定。我们假设，在心力衰竭患者中，通过CPAP治疗并存的OSA会增加早晨的HF-HRV。在19例心力衰竭（左心室射血分数<45%）合并OSA（睡眠时呼吸暂停和呼吸浅慢≥20次/小时）的患者中，在随机分为对照组或CPAP治疗组之前及之后1个月对HF-HRV进行了量化。在对照组（n = 7）中，在为期1个月的早晨清醒状态研究期间，HF-HRV没有变化。在CPAP治疗组（n = 12）中，由于肺容积变化与HF-HRV变化之间的传递函数增加（从92.37±96.03增加到219.07±177.14 ms/l；P = 0.01），早晨清醒时HF-HRV显著增加[从2.43±0.55增加到2.82±0.50 log(ms²/Hz)；P = 0.002]。总之，心力衰竭患者夜间使用CPAP治疗并存的OSA可增加早晨清醒时的HF-HRV，表明心率的迷走神经调节得到改善。这可能有助于改善预后。
