心率变异性的混沌特征与脑卒中患者预后

Fractal dimension of heart rate variability:a useful marker to predict the sudden death in patients with stroke

目的 探讨心率变异性混沌特征参数 分维数 (fractaldimension ,FD)变化预测脑卒中患者发生死亡和猝死的价值及贝它乐克对FD的影响。方法 检测 2 5 0例急性期脑卒中患者和 2 0 6例健康对照的FD ,分析脑卒中患者发生死亡和猝死与其FD变化之间的关系 ,然后用随机对照方法检测贝它乐克对 6 2例脑梗死患者FD的影响。结果 FD≤ 1 .0 5为预测脑卒中患者发生猝死的最佳临界点 ;FD≤ 1 .0 5预测脑卒中患者发生猝死的敏感性为 71 .4 2 % ,特异性为 90 .2 5 % ,准确性为 89.2 0 % ,阳性预报值为 30 .30 % ,阳性似然比为 7.33。贝它乐克可明显改善脑梗死患者的FD值。结论 FD能有效预测脑卒中患者猝死的发生 ,FD≤ 1 .0 5的脑卒中患者预后不良。检测FD有助于发现处于猝死高危状态的脑卒中患者 。

Objective To assess the value of fractal dimension(FD)in the prediction of sudden unexpected death and the effects of oral betaloc on FD in patients with stroke.Methods FD of heart rate variability(HRV)were measured and analyzed with ECG recordings in 250 patients with hemispheric cerebral infarction and hemorrhage in the acute phase and in 206 control subjects.The patients with cerebral infarction were assigned at random to receive standrad management only(control group),or standrad management and treatment with betaloc for two weeks.Results FD≤1.05 was the optimum cut off points for the prediction of sudden unexpected death in patients with stroke.FD≤1.05 had a sensitivity of 71.42%,a specificity of 90.25%,a positive predictive accuracy of 30.3%,and a positive likelihood ratio of 7.33 for sudden unexpected death events.After betaloc treatment FD increased obviously(P<0.05).Conclusion FD may be a useful marker to predict the sudden unexpected death events in patients with stroke,it can select a small subgroup of survivors of stroke at high risk of sudden death.β adrenergic blocking agents is good for cerebral infarction patients with lower FD.