论文部分内容阅读
目的通过心电生理学相关指标即心率变异性和核素脑血流显像的研究,了解自主神经系统所起的作用,及对血管性迷走性晕厥的诊断价值和定性与定量的情况。方法分别选取有晕厥病史的65例实验组,无晕厥病史30例对照组。检测静息状态下核素脑血流显像,然后分别进行直立倾斜试验,试验同时检测心率变异性;试验后,立即进行核素脑血流定量分析和断层显像,以测定左、右大脑半球平均脑血流量。将心率变异性与倾斜试验对比,脑血流量前后对比,并行统计学分析。结果倾斜前三组低频段之间没有显著差异(P>0.05),倾斜后三组低频段进行性升高,阳性组出现显著升高,与阴性组和对照组之间有显著性差异(P<0.05);阳性反应或结束前低频段开始下降,且阳性组明显下降,与其他两组相比有显著性差异(P<0.05);倾斜前三组高频段之间没有显著差异(P>0.05),倾斜后高频段进行性下降,阳性组下降明显,与阴性组和对照组相比有显著性差异(P<0.05);阳性组在晕厥前显著升高,与阴性组和对照组之间有显著性差异(P<0.05)。低频段与高频段之比较试验前三组之间没有显著性差异(P>0.05),倾斜后阳性组明显升高,与阴性组和对照组比较有极显著性差异(P<0.01);阳性反应或结束前,阳性组明显降低,与阴性组和对照组比较有极显著性差异(P<0.01);早期最大心率变化阳性组明显升高,与阴性组和对照组比较同样有极显著性差异(P<0.01)。倾斜试验阴性组中有5例心率变异性与阳性组类似,与其他阴性组之间有显著性差异(P<0.05)。倾斜前三组平均脑血流量无差异性,阳性组晕厥时脑血流量较阴性组及对照组显著下降(P<0.05);晕厥前后脑血流量对比阳性组与阴性组和对照组对比有显著性差异(P<0.05)。阳性组中5例心率变异性与其他阴性组有差异者,脑血流测定结束与其他阴性者同样有显著性差著(P<0.05)。结论血管迷走性晕厥时交感神经活动减弱,相对迷走神经活动增加,表明交感神经和副交感神经功能调节障碍在血管迷走性晕厥发生机制中起着重要作用。LPF/HPF 比值能确切地反映两者在诱发血管迷走性晕厥中的相互作用,早期最大心率变化可预测试验结果,有利于血管迷走性晕厥的早期诊断及治疗。晕厥时脑血流量下降,在脑额叶血液灌注不足最明显。
OBJECTIVE: To understand the role of the autonomic nervous system (CNS) and the diagnostic value and qualitative and quantitative assessment of vasovagal syncope based on the study of heart rate variability and radionuclide cerebral blood flow imaging. Methods 65 cases with syncope history, 30 cases without syncope history. Cerebral blood flow imaging was performed under resting state, and then vertical tilt test was performed separately. The heart rate variability was also tested. After the test, quantitative analysis of cerebral blood flow and tomography were performed to determine whether left and right brains Hemispheric mean cerebral blood flow. The heart rate variability compared with the tilt test, cerebral blood flow before and after contrast, parallel statistical analysis. Results There was no significant difference (P> 0.05) between the low frequency bands of the first three groups after tilting, but increased in the low frequency bands of the three groups after tilting. There was a significant difference between the negative group and the control group (P (P <0.05). The positive reaction or the low frequency band before the end began to decline, and the positive group was significantly decreased compared with the other two groups (P <0.05); there was no significant difference between the high frequency bands of the first three groups (P> 0.05). After tilted, the high frequency band decreased significantly. The positive group decreased significantly, which was significantly different from the negative group and the control group (P <0.05). The positive group increased significantly before syncope. Compared with the negative group and the control group There was a significant difference (P <0.05). There was no significant difference (P> 0.05) between the low frequency band and the high frequency band before the test, and the positive group after the tilt was significantly higher than that of the negative group and the control group (P <0.01); the positive Before the reaction or the end, the positive group decreased significantly compared with the negative group and the control group (P <0.01), the positive rate of early maximum heart rate increased significantly, compared with the negative group and the control group were also extremely significant Difference (P <0.01). There were 5 heart rate variability similar to the positive group in the tilt test negative group and significant difference with other negative group (P <0.05). Cerebral blood flow in the positive group was significantly lower than that in the negative group and the control group (P <0.05). The cerebral blood flow in the positive group was significantly lower than that in the negative group and the control group Sex differences (P <0.05). Positive rate of 5 cases of heart rate variability and other negative groups were different, the end of cerebral blood flow measurement and other negative as significant difference (P <0.05). Conclusions Sympathetic nerve activity weakened and relative vagal activity increased during vasovagal syncope, suggesting that sympathetic and parasympathetic dysfunction play an important role in the pathogenesis of vasovagal syncope. LPF / HPF ratio can accurately reflect the two in the induced vasovagal syncope in the interaction, early changes in maximum heart rate can predict the test results, is conducive to the early diagnosis and treatment of vasovagal syncope. Cerebral blood flow decreased in syncope, the most obvious lack of blood perfusion in the frontal lobe.