Department of Hypertension and Diabetology, Hypertension Unit bDepartment of Neurology for Adults, Medical University of Gdańsk, Gdańsk, Poland.
J Hypertens. 2013 Aug;31(8):1629-36. doi: 10.1097/HJH.0b013e328361e48b.
Heart rate variability (HRV) as a measure of autonomic function might provide prognostic information in ischemic stroke. However, numerous difficulties are associated with HRV parameters assessment and interpretation, especially in short-term ECG recordings. For better understanding of derived HRV data and to avoid methodological bias we simultaneously recorded and analyzed heart rate, blood pressure and respiratory rate.
Seventy-five ischemic stroke patients underwent short-term ECG recordings. Linear and nonlinear parameters of HRV as well as beat-to-beat blood pressure and respiratory rate were assessed and compared in patients with different functional neurological outcomes at 7th and 90th days.
Values of Approximate, Sample and Fuzzy Entropy were significantly lower in patients with poor early neurological outcome. Patients with poor 90-day outcome had higher percentage of high frequency spectrum and normalized high frequency power, lower normalized low frequency power and lower low frequency/high frequency ratio. Low frequency/high frequency ratio correlated negatively with scores in the National Institutes of Health Stroke Scale and modified Rankin Scale (mRS) at the 7th and mRS at the 90th days. Mean RR interval, values of blood pressure as well as blood pressure variability did not differ between groups with good and poor outcomes. Respiratory frequency was significantly correlated with the functional neurological outcome at 7th and 90th days.
While HRV assessed by linear methods seems to have long-term prognostic value, complexity measures of HRV reflect the impact of the neurological state on distinct, temporary properties of heart rate dynamic. Respiratory rate during the first days of the stroke is associated with early and long-term neurological outcome and should be further investigated as a potential risk factor.
心率变异性（HRV）作为自主神经功能的一种衡量标准，可能为缺血性脑卒中提供预后信息。然而，HRV 参数评估和解释存在诸多困难，尤其是在短期心电图记录中。为了更好地理解衍生的 HRV 数据并避免方法学偏见，我们同时记录和分析了心率、血压和呼吸率。
75 例缺血性脑卒中患者接受了短期心电图记录。在第 7 天和第 90 天，我们评估并比较了不同神经功能结局患者的 HRV 线性和非线性参数以及逐搏血压和呼吸率。
早期神经功能结局不良的患者近似熵、样本熵和模糊熵值显著降低。90 天预后不良的患者高频谱百分比和归一化高频功率较高，归一化低频功率较低，低频/高频比值较低。低频/高频比值与第 7 天 NIH 卒中量表和改良 Rankin 量表（mRS）评分以及第 90 天 mRS 评分呈负相关。RR 间期均值、血压值和血压变异性在预后良好和不良的组间无差异。呼吸频率与第 7 天和第 90 天的神经功能结局显著相关。
虽然线性方法评估的 HRV 似乎具有长期预后价值，但 HRV 的复杂性测量反映了神经状态对心率动态特定、暂时特征的影响。卒中后最初几天的呼吸频率与早期和长期神经结局相关，应进一步作为潜在风险因素进行研究。
