心率变异性对儿童不明原因晕厥的诊断价值

Diagnostic values of heart rate variability on unexplained syncope in children

目的:通过测定不明原因晕厥儿童的心率变异性(heart rate variability,HRV),研究其对不明原因晕厥儿童的诊断价值。方法:对49例不明原因晕厥儿童行直立倾斜试验(head up tilt test,HUT)诊断及动态心电图监测,分析HUT阳性患儿与阴性患儿HRV的差异。采用受试者操作特征(receiver operating characteristic,ROC)曲线分析HRV对不明原因晕厥患儿的诊断价值。结果:49例不明原因晕厥患儿经HUT诊断后,32例(65.3%)诊断明确,HUT的诊断阳性率为65.3%。HUT阳性组的SDNNi、rMSSD、TP、ULF、VLF、LF以及HF均明显高于HUT阴性组(P<0.05)。HUT阳性组的SDNN、pNN50以及三角指数与HUT阴性组相比,差异均无统计学意义(P>0.05)。SDNNi、rMSSD、TP、ULF、VLF、LF和HF对HUT的诊断预测具有一定价值。分别以ULF、LF和HF 12 947.00、9 462.50和9 509.00作为界值时,对诊断阳性率的预测效果较好,灵敏度分别为75.0%、68.8%和68.8%,特异度分别为64.7%、64.7%和64.7%。结论:HRV中的ULF、LF和HF可作为HUT诊断自主神经介导性晕厥的预测指标,界值分别为12 947.00、9 462.50和9 509.00,具有较好的灵敏度和特异度。

Objective：To investigate the diagnostic values of heart rate varibility （HRV） on unex- plained syncope （UPS） in children. Methods： Forty-nine children with unexplained syncope underwent head-up tilt test （HUT） and Hoher monitering, then the differences were analyzed between HUT positive children and HUT negative children. The receiver operating characteristic （ROC） curve was used to ex- plore the diagnostic values of HRV. Results： Of the 49 patients, 32 （65.3 % ） were HUT positive. The diagnostic positive rate of HUT was 65.3%. The SDNNi, rMSSD, TP, ULF, VLF, LF and HF in the HUT positive group were significantly higher than those in the HUT negative group （P 〈 0.05）, respec- tively. There were no significant differences in SDNN, pNNS0 and triangular index between the patients with different HUT outcomes （P 〉 0.05 ）. The ROC curve on the predictive values of SDNNi, rMSSD, TP, ULF, VLF, LF and HF showed that ULF, LF, and HF （ 12 947.00, 9 462.50, and 9 509.00） as cutting values produced both high sensitivity （75.0%, 68.8%, and 68.8% ） and specificity （64.7% , 64.7%, and 64.7% ） to predict the diagnostic values of HUT for diagnosing unexplained syncope. Con- clusion： ULF, LF and HF can be considered as indicators for diagnosing neurally-mediated syncope in children. ULF, LF, and HF （12 947.00, 9 462.50, and 9 509.00） taken as cutting values may pro- duce both high sensitivity and specificity.