Sleep Research Laboratory, Centre for Sleep Health and Research, and Department of Medicine, University Health Network Toronto Rehabilitation Institute and Toronto General Hospital, Toronto, Ontario, Canada.
Am J Respir Crit Care Med. 2013 Feb 15;187(4):433-8. doi: 10.1164/rccm.201205-0894OC. Epub 2012 Dec 13.
Obstructive sleep apnea and central sleep apnea increase risk of mortality in patients with heart failure (HF), possibly because of hemodynamic compromise during sleep. However, beat-to-beat stroke volume (SV) has not been assessed in response to obstructive and central events during sleep in patients with HF. Because obstructive events generate negative intrathoracic pressure that reduces left ventricular (LV) preload and increases afterload, but central events do not, obstructive events should lead to greater hemodynamic compromise than central events.
To determine the effects of obstructive and central apneas and hypopneas during sleep on SV in patients with HF.
Patients with systolic HF (LV ejection fraction ≤ 45%) and sleep apnea underwent beat-to-beat measurement of SV by digital photoplethysmography during polysomnography. Change in SV from before to the end of obstructive and central respiratory events was calculated and compared between these types of events.
Changes in SV were assessed during 252 obstructive and 148 central respiratory events in 40 patients with HF. Whereas SV decreased by 6.8 (±8.7)% during obstructive events, it increased by 2.6 (±5.4)% during central events (P < 0.001 for difference). For obstructive events, reduction in SV was associated independently with LV ejection fraction, duration of respiratory events, and degree of oxygen desaturation.
In patients with HF, obstructive and central respiratory events have opposite hemodynamic effects: whereas obstructive sleep apnea appears to have an adverse effect on SV, central sleep apnea appears to have little or slightly positive effects on SV. These observations may have implications for therapeutic approaches to these two breathing disturbances.
阻塞性睡眠呼吸暂停和中枢性睡眠呼吸暂停会增加心力衰竭（HF）患者的死亡率，这可能是由于睡眠期间血流动力学受到影响。然而，HF 患者在睡眠期间针对阻塞性和中枢性事件的每搏量（SV）尚未进行评估。由于阻塞性事件会产生负的胸腔内压力，从而降低左心室（LV）前负荷并增加后负荷，但中枢性事件不会，因此阻塞性事件应比中枢性事件导致更大的血流动力学损伤。
确定睡眠期间阻塞性和中枢性呼吸暂停及低通气对 HF 患者 SV 的影响。
接受睡眠呼吸暂停治疗的收缩性 HF（LV 射血分数≤45%）患者在多导睡眠图检查期间通过数字光体积描记法进行 SV 的逐搏测量。计算并比较这些类型的事件中 SV 从开始到结束的变化。
在 40 名 HF 患者的 252 次阻塞性呼吸事件和 148 次中枢性呼吸事件中评估了 SV 的变化。阻塞性事件期间 SV 降低了 6.8（±8.7）%，而中枢性事件期间 SV 增加了 2.6（±5.4）%（差异具有统计学意义，P<0.001）。对于阻塞性事件，SV 的降低与 LV 射血分数、呼吸事件持续时间和氧去饱和程度独立相关。
在 HF 患者中，阻塞性和中枢性呼吸事件具有相反的血流动力学效应：虽然阻塞性睡眠呼吸暂停似乎对 SV 有不利影响，但中枢性睡眠呼吸暂停对 SV 的影响似乎较小或几乎为正。这些观察结果可能对这两种呼吸紊乱的治疗方法有影响。
