In patients with spinal muscular atrophy (SMA), obstructive sleep apnea syndrome (OSAS) constitutes an important cause of cardiovascular morbidity and mortality. We investigated heart rate variability (HRV) to evaluate the effects of non-invasive mechanical ventilation on cardiac autonomic dysfunction in patients with SMA and OSAS. Six patients with SMA (type 1 and 2) and six age- and sex-matched healthy children were consecutively enrolled. A whole-night diagnostic polysomnography was performed, and SMA patients with OSAS were given non-invasive mechanical ventilation therapy. HRV analysis was performed on the basis of whole-night electrocardiography recordings via a computer-base program. Apnea-hypopnea index (AHI) was 9.2 ± 6.2/hr in SMA patients, while it was 0.4 ± 0.5/hr in controls (p = 0.036). All SMA patients had OSAS, while none of the controls had OSAS (p = 0.012). Mean percentage of successive R wave of QRS complex (R-R) intervals>50 ms was significantly lower in SMA patients than those in controls (p = 0.031). Significant correlations were found between AHI and high-frequency power, low/high-frequency ratio in wakefulness and in sleep (p<0.05). Repeated HRV analysis in SMA patients following OSAS therapy showed significant reductions in average R-R duration (p = 0.028) and percentage of successive R-R intervals>50 ms (p = 0.043). Our study demonstrates the beneficial effects of non-invasive mechanical ventilation on cardiac autonomic dysfunction in SMA patients with OSAS.

中文翻译：

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无创机械通气对脊髓性肌萎缩患者心脏自主神经功能障碍的影响

在脊髓性肌萎缩症 (SMA) 患者中，阻塞性睡眠呼吸暂停综合征 (OSAS) 是导致心血管发病率和死亡率的重要原因。我们调查了心率变异性 (HRV)，以评估无创机械通气对 SMA 和 OSAS 患者心脏自主神经功能障碍的影响。连续招募了 6 名 SMA 患者（1 型和 2 型）和 6 名年龄和性别匹配的健康儿童。进行了整夜诊断性多导睡眠监测，并对患有 OSAS 的 SMA 患者进行了无创机械通气治疗。HRV 分析是通过基于计算机的程序在整夜心电图记录的基础上进行的。SMA 患者的呼吸暂停低通气指数 (AHI) 为 9.2 ± 6.2/hr，而对照组为 0.4 ± 0.5/hr (p = 0.036)。所有 SMA 患者都患有 OSAS，而没有一个对照有 OSAS (p = 0.012)。SMA 患者 QRS 复合波 (RR) 间隔 > 50 ms 的连续 R 波的平均百分比显着低于对照组（p = 0.031）。发现 AHI 与高频功率、清醒和睡眠中的低频/高频比之间存在显着相关性（p<0.05）。OSAS 治疗后 SMA 患者的重复 HRV 分析显示平均 RR 持续时间 (p = 0.028) 和连续 RR 间期百分比 > 50 ms (p = 0.043) 显着减少。我们的研究证明了无创机械通气对患有 OSAS 的 SMA 患者心脏自主神经功能障碍的有益影响。发现 AHI 与高频功率、清醒和睡眠中的低频/高频比之间存在显着相关性（p<0.05）。OSAS 治疗后 SMA 患者的重复 HRV 分析显示平均 RR 持续时间 (p = 0.028) 和连续 RR 间期百分比 > 50 ms (p = 0.043) 显着减少。我们的研究证明了无创机械通气对患有 OSAS 的 SMA 患者心脏自主神经功能障碍的有益影响。发现 AHI 与高频功率、清醒和睡眠中的低频/高频比之间存在显着相关性（p<0.05）。OSAS 治疗后 SMA 患者的重复 HRV 分析显示平均 RR 持续时间 (p = 0.028) 和连续 RR 间期百分比 > 50 ms (p = 0.043) 显着减少。我们的研究证明了无创机械通气对患有 OSAS 的 SMA 患者心脏自主神经功能障碍的有益影响。