This study was to investigate the changes of autonomic nerve function and hemodynamics in patients with vasovagal syncope(VVS) during head-up tilt-table testing(HUT). HUT was performed in 68 patients with unexplained ...This study was to investigate the changes of autonomic nerve function and hemodynamics in patients with vasovagal syncope(VVS) during head-up tilt-table testing(HUT). HUT was performed in 68 patients with unexplained syncope and 18 healthy subjects served as control group. According to whether bradycardia, hypotension or both took place during the onset of syncope, the patients were divided during the test into three subgroups: vasodepressor syncope(VD), cardioinhibitory syncope(CI) and mixed syncope(MX) subgroups. Heart rate, blood pressure, heart rate variability(HRV), and deceleration capacity(DC) were continuously analyzed during HUT. For all the subjects with positive responses, the normalized low frequency(LFn) and the LF/HF ratio markedly decreased whereas normalized high frequency(HFn) increased when syncope occurred. Syncopal period also caused more significant increase in the power of the DC in positive groups. These changes were more exaggerated compared to controls. All the patients were indicative of a sympathetic surge in the presence of withdrawal vagal activity before syncope and a sympathetic inhibition with a vagal predominance at the syncopal stage by the frequency-domain analysis of HRV. With the measurements of DC, a decreased vagal tone before syncope stage and a vagal activation at the syncopal stage were observed. The vagal tone was higher in subjects showing cardioinhibitory responses at the syncopal stage. DC may provide an alternative method to understand the autonomic profile of VVS patients.展开更多
Objective To study thechanges of baroreflex sensitivity (BRS) during head - up tilt test (HUT) in patients with vasovagal syncope (VS), and to examine the relationship between baroreflex sensitivity and neurohormonal ...Objective To study thechanges of baroreflex sensitivity (BRS) during head - up tilt test (HUT) in patients with vasovagal syncope (VS), and to examine the relationship between baroreflex sensitivity and neurohormonal factors. Furthermore, to investigate the effects of the changes of BRS on VS. Methods Forty - two patients with unexplained syncope (Among the 42 patients, there were 22 patients with positive HUT and 20 patients with negative HUT respectively) and 20 healthy volunteers (with negative HUT) underwent passive head - up tilt testing, Ante-cubital vein blood samples were taken before and after HUT, or at syncope. The fasting plasma endothelin , serum nitric oxide (NO), serum NE were measured, the BRS was assessed on the basis of the linear regression slope the RR interval versus systolic arterial blood pressure during the increment in blood pressure after intravenous administration of phenylephrine. Results (1) During the syncope, the BRS significantly reduced in HUT(+) group than baseline. At the end of tilt, the level of plasma ET, serum NO in patients with positive HUT significantly increased compared with baseline or normal controls, and the plasma concentration of NE also had the trend of increase. (2) By multiple regression analysis, a significant negative correlation was found between baroreceptor sensitivity and the plasma ET, NO at the end of HUT in patients with positive HUT, but there was no relationship between BRS and NE. Conclusions During the syncope occure, the BRS in patients with VS decreased significantly compared with normal controls. The abnormal plasma ET, NO concen-tration might contribute to the mechanism of VS.展开更多
To investigate age and sex distribution of vasovagal syncope （VVS） patients undergoing head-up tilt table test （HUTT） at a tertiary hospital. The details of syncope patients who underwent HUTT at our department of...To investigate age and sex distribution of vasovagal syncope （VVS） patients undergoing head-up tilt table test （HUTT） at a tertiary hospital. The details of syncope patients who underwent HUTT at our department of cardiac function from January 2004 to December 2010 were reviewed. Of the 1 799 patients who underwent the HUTT, 854 tested positive, of which 558 （65.3%） were women, which were more than the women in the negative group （450, 47.6%） （p〈0.05）. VVS patients showed a bimodal age distribution between 11 and 20 years of age and in the fourth decade. In almost all age groups, mixed response was the highest compared with vasodepressor and cardioinhibitory. VVS patients who underwent HUTT indicate bimodal distribution peaking before the second decade and the fourth decade. The incidence of females was twice that of males before the sixth decade, and old age occupies a small percentage of VVS with no other comorbidities.展开更多
目的：探讨单中心中国人直立性高血压（orthostatic hypertension，OHT）的年龄和性别差异。方法：选择2000年1月至2012年8月在中南大学湘雅二医院晕厥专科门诊就诊或住院的不明原因头晕、晕厥等患者2 994例进行直立倾斜试验（head-up t...目的：探讨单中心中国人直立性高血压（orthostatic hypertension，OHT）的年龄和性别差异。方法：选择2000年1月至2012年8月在中南大学湘雅二医院晕厥专科门诊就诊或住院的不明原因头晕、晕厥等患者2 994例进行直立倾斜试验（head-up tilt test，HUTT）检查，年龄2.00~78.00（19.07±14.78）岁，男1 406例，女1 588例。符合OHT者745例，分为成人组（≥18岁，247例）和儿童组（〈18岁，498例），分析OHT出现率、OHT类型及HUTT后3 min血压增加量的年龄与性别差异。结果：1）OHT出现率为24.88%（745/2 994），男女比较差异未见统计学意义（25.75% vs 24.12%，χ2=1.058，P〉0.05）；成人组较儿童组出现率高（27.05% vs 23.83%，χ2=4.125，P〈0.05）；745例OHT患者中52例（6.98%）表现为直立后收缩压、舒张压均升高（sOHT合并dOHT），16例（2.15%）为单纯直立性高收缩压（sOHT），677例（90.87%）为单纯直立性高舒张压（dOHT）。成人组单纯sOHT出现率、sOHT合并dOHT出现率均明显高于儿童组（分别为1.11% vs 0.29%，χ2=7.965，P〈0.01；2.88% vs 1.24%，χ2=9.849，P〈0.01）；成人组单纯dOHT出现率与儿童组比较差异未见统计学意义（23.56% vs 22.20%，χ2=0.668，P〉0.05）；sOHT合并dOHT与单纯dOHT在不同性别组中出现率差异未见统计学意义（男：1.71% vs 1.76%，χ2=0.014，P〉0.05；女：23.68% vs 21.66%，χ2=1.742，P〉0.05）；但儿童中dOHT出现率男性高于女性（24.53% vs 19.74%，χ2=6.933，P〈0.05）。2）与儿童组比较，成人组sOHT合并dOHT收缩压增加量[（25.62±4.96） mmHg vs （23.54±5.83） mmHg，t=1.385，P〉0.05]、dOHT舒张压增加量[（13.46±3.49） mmHg vs （13.23±3.22） mmHg， t=0.840，P〉0.05]差异均无统计学意义。与儿童组比较，成人组sOHT收缩压增加量[（25.44±4.96） mmHg vs （23.68±5.35 ） mmHg，t=1.411，P〉0.05]及dOHT舒张压增加量[（14.09±4.28） mmHg vs （13.05±3.82） mmHg，t=1.887，P〉0.05]差异均未见统计学意义。结论：OHT出现率成人高于儿童，以dOHT多见，儿童以男性多见。在sOHT合并dOHT与单纯dOHT中，直立后3 min血压增加量成人与儿童未见差异。展开更多
基金supported by a grant from the Wuhan Science and Technology Program of China(No.2014060101010032)
文摘This study was to investigate the changes of autonomic nerve function and hemodynamics in patients with vasovagal syncope(VVS) during head-up tilt-table testing(HUT). HUT was performed in 68 patients with unexplained syncope and 18 healthy subjects served as control group. According to whether bradycardia, hypotension or both took place during the onset of syncope, the patients were divided during the test into three subgroups: vasodepressor syncope(VD), cardioinhibitory syncope(CI) and mixed syncope(MX) subgroups. Heart rate, blood pressure, heart rate variability(HRV), and deceleration capacity(DC) were continuously analyzed during HUT. For all the subjects with positive responses, the normalized low frequency(LFn) and the LF/HF ratio markedly decreased whereas normalized high frequency(HFn) increased when syncope occurred. Syncopal period also caused more significant increase in the power of the DC in positive groups. These changes were more exaggerated compared to controls. All the patients were indicative of a sympathetic surge in the presence of withdrawal vagal activity before syncope and a sympathetic inhibition with a vagal predominance at the syncopal stage by the frequency-domain analysis of HRV. With the measurements of DC, a decreased vagal tone before syncope stage and a vagal activation at the syncopal stage were observed. The vagal tone was higher in subjects showing cardioinhibitory responses at the syncopal stage. DC may provide an alternative method to understand the autonomic profile of VVS patients.
文摘Objective To study thechanges of baroreflex sensitivity (BRS) during head - up tilt test (HUT) in patients with vasovagal syncope (VS), and to examine the relationship between baroreflex sensitivity and neurohormonal factors. Furthermore, to investigate the effects of the changes of BRS on VS. Methods Forty - two patients with unexplained syncope (Among the 42 patients, there were 22 patients with positive HUT and 20 patients with negative HUT respectively) and 20 healthy volunteers (with negative HUT) underwent passive head - up tilt testing, Ante-cubital vein blood samples were taken before and after HUT, or at syncope. The fasting plasma endothelin , serum nitric oxide (NO), serum NE were measured, the BRS was assessed on the basis of the linear regression slope the RR interval versus systolic arterial blood pressure during the increment in blood pressure after intravenous administration of phenylephrine. Results (1) During the syncope, the BRS significantly reduced in HUT(+) group than baseline. At the end of tilt, the level of plasma ET, serum NO in patients with positive HUT significantly increased compared with baseline or normal controls, and the plasma concentration of NE also had the trend of increase. (2) By multiple regression analysis, a significant negative correlation was found between baroreceptor sensitivity and the plasma ET, NO at the end of HUT in patients with positive HUT, but there was no relationship between BRS and NE. Conclusions During the syncope occure, the BRS in patients with VS decreased significantly compared with normal controls. The abnormal plasma ET, NO concen-tration might contribute to the mechanism of VS.
基金Supported by the National Natural Science Foundation of China (30972954)
文摘To investigate age and sex distribution of vasovagal syncope （VVS） patients undergoing head-up tilt table test （HUTT） at a tertiary hospital. The details of syncope patients who underwent HUTT at our department of cardiac function from January 2004 to December 2010 were reviewed. Of the 1 799 patients who underwent the HUTT, 854 tested positive, of which 558 （65.3%） were women, which were more than the women in the negative group （450, 47.6%） （p〈0.05）. VVS patients showed a bimodal age distribution between 11 and 20 years of age and in the fourth decade. In almost all age groups, mixed response was the highest compared with vasodepressor and cardioinhibitory. VVS patients who underwent HUTT indicate bimodal distribution peaking before the second decade and the fourth decade. The incidence of females was twice that of males before the sixth decade, and old age occupies a small percentage of VVS with no other comorbidities.
文摘目的：探讨单中心中国人直立性高血压（orthostatic hypertension，OHT）的年龄和性别差异。方法：选择2000年1月至2012年8月在中南大学湘雅二医院晕厥专科门诊就诊或住院的不明原因头晕、晕厥等患者2 994例进行直立倾斜试验（head-up tilt test，HUTT）检查，年龄2.00~78.00（19.07±14.78）岁，男1 406例，女1 588例。符合OHT者745例，分为成人组（≥18岁，247例）和儿童组（〈18岁，498例），分析OHT出现率、OHT类型及HUTT后3 min血压增加量的年龄与性别差异。结果：1）OHT出现率为24.88%（745/2 994），男女比较差异未见统计学意义（25.75% vs 24.12%，χ2=1.058，P〉0.05）；成人组较儿童组出现率高（27.05% vs 23.83%，χ2=4.125，P〈0.05）；745例OHT患者中52例（6.98%）表现为直立后收缩压、舒张压均升高（sOHT合并dOHT），16例（2.15%）为单纯直立性高收缩压（sOHT），677例（90.87%）为单纯直立性高舒张压（dOHT）。成人组单纯sOHT出现率、sOHT合并dOHT出现率均明显高于儿童组（分别为1.11% vs 0.29%，χ2=7.965，P〈0.01；2.88% vs 1.24%，χ2=9.849，P〈0.01）；成人组单纯dOHT出现率与儿童组比较差异未见统计学意义（23.56% vs 22.20%，χ2=0.668，P〉0.05）；sOHT合并dOHT与单纯dOHT在不同性别组中出现率差异未见统计学意义（男：1.71% vs 1.76%，χ2=0.014，P〉0.05；女：23.68% vs 21.66%，χ2=1.742，P〉0.05）；但儿童中dOHT出现率男性高于女性（24.53% vs 19.74%，χ2=6.933，P〈0.05）。2）与儿童组比较，成人组sOHT合并dOHT收缩压增加量[（25.62±4.96） mmHg vs （23.54±5.83） mmHg，t=1.385，P〉0.05]、dOHT舒张压增加量[（13.46±3.49） mmHg vs （13.23±3.22） mmHg， t=0.840，P〉0.05]差异均无统计学意义。与儿童组比较，成人组sOHT收缩压增加量[（25.44±4.96） mmHg vs （23.68±5.35 ） mmHg，t=1.411，P〉0.05]及dOHT舒张压增加量[（14.09±4.28） mmHg vs （13.05±3.82） mmHg，t=1.887，P〉0.05]差异均未见统计学意义。结论：OHT出现率成人高于儿童，以dOHT多见，儿童以男性多见。在sOHT合并dOHT与单纯dOHT中，直立后3 min血压增加量成人与儿童未见差异。
