Circulation：睡眠呼吸障碍增加慢性心衰患者致死性室性心律失常的发生

慢性心力衰竭（Chronic heart failure，CHF）在临床上十分常见，近年来随着药物及器械治疗的飞速进展，CHF的预后得到了很大的改善，但是CHF仍然有很高的死亡率和心脏性猝死的发生率。为改善CHF的预后，我们需要积极寻找增加患者死亡率和心脏性猝死发生率的因素。
近年来的研究表明，约50%的慢性心力衰竭患者合并睡眠呼吸障碍，包括阻塞性睡眠呼吸障碍和中枢性睡眠呼吸障碍，多项大规模临床研究表明，睡眠呼吸障碍与心衰患者不良预后相关，也有研究表明，睡眠呼吸障碍可增加CHF患者房颤的发生率，然而睡眠呼吸障碍是否增加CHF患者致死性室性心律失常的发生目前还不清楚，据此，Yamada S等进行了一项临床研究。
该研究共入选50例CHF合并睡眠呼吸障碍的患者，其中33例为男性，平均年龄61岁。所有患者同时进行Holter监测和睡眠呼吸监测，测定每6小时的T波电交替(0-6小时，6-12小时，12-18小时，18-24小时)，评估T波电交替的昼夜节律变化，并测定各时段的心率变异性。根据睡眠监测结果，将患者分成2组：A组睡眠紊乱指数>20次/小时，B组睡眠紊乱指数≤20次/分；分别比较两组的T波电交替、心率变异性和室性心动过速（>5个心搏）发生情况。结果提示：A组患者所有时段的T波电交替均大于B组患者，低频及高频心率变异性A组均低于B组，更为重要的是，A组患者室性心动过速的发生多于B组患者。
根据该项研究可得出以下结论：睡眠呼吸障碍可导致慢性心衰患者心电学不稳定，可增加致死性室性心律失常的发生。

 与慢性心力衰竭相关的拓展阅读：

• Nile公司cenderitide治疗慢性心力衰竭I期临床试验取得满意结果
• 2008年ESC急慢性心力衰竭诊断治疗指南
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Sleep-Disordered Breathing Increases Risk for Fatal Ventricular Arrhythmias in Patients With Chronic Heart Failure.
Background
It has been shown that sleep-disordered breathing (SDB) is associated with adverse prognosis in patients with chronic heart failure (CHF), but little is known about the relationship between SDB and life-threatening arrhythmias.
Methods and Results
 Fifty patients with CHF and SDB (33 male; mean age, 61 years) underwent Holter electrocardiogram and portable sleep monitoring simultaneously. The circadian variation in positive T-wave alternans (TWA; >65μV) was determined during 6-h intervals (0-6, 6-12, 12-18, and 18-24h). In addition, power spectral analysis of heart rate variability (HRV) was evaluated across a 24-h period. The subjects were divided into 2 groups based on whether respiratory disturbance index was ≥20events/h (Group A, n=24) or not (Group B, n=26). The prevalence of positive TWA, parameters in HRV and the occurrence of ventricular tachycardia (>5 beats) were compared between the 2 groups. The prevalence of positive TWA in Group A was significantly higher than that in Group B in all 6-h intervals. Low-frequency and high-frequency powers of HRV were significantly lower in Group A than in Group B across a 24-h period. Importantly, the prevalence of ventricular tachycardia was significantly higher in Group A than in Group B (46% vs. 19%, P=0.04).
Conclusions
 SDB may induce cardiac electrical instability associated with life-threatening arrhythmias across a 24-h period in CHF.