【作者】 王成；

【导师】 易著文；

【作者基本信息】 中南大学 ， 儿科学， 2007， 博士

【摘要】 目的对儿童血管迷走性晕厥(VVS)进行直立倾斜试验(HUTT)诊断及其影响因素分析,探讨儿童VVS与血清胰岛素(INS)、C肽(CP)及血、尿电解质的初步关系,研究盐酸米多君与美托洛尔对儿童VVS的干预效果及其机制。方法2001年1月-2007年4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晕厥或晕厥先兆儿童301例,年龄3.08-18(平均11.82±3.16)岁,男125例,女176例。匹配健康儿童27例为对照。HUTT采用基础直立倾斜试验(BHUT)及舌下含化硝酸甘油倾斜试验(SNHUT),检测各时间点心率、收缩压及舒张压。对其中2004年6月-2007年4月晕厥儿童(n=79)及健康对照(n=11)检测基础状态血清INS、CP、空腹血糖(FPG)及血浆肾素活性(PRA)、血管紧张素Ⅱ(AⅡ)、醛固酮(ALD)和血、尿电解质。选取2003年01月-2007年04月晕厥儿童(n=51)在非药物治疗基础上,随机给予盐酸米多君和美托洛尔治疗。微机通过SPSS 11.5软件包将检测结果进行统计学分析。结果①BHUT阳性率23.92%,SNHUT将阳性率提高到57.81%。晕厥发作时间在BHUT为(22.54±10.82)min,SNHUT为(5.47±2.78)min,在反应类型之间无差异(p＞0.05)。②HUTT过程心率、收缩压、舒张压变化与受试者年龄、性别、倾斜角度、临床晕厥频次无明显关系(多数时间点表现为p＞0.05)。HUTT阳性在试验终止时的血流动力学变化与是否使用硝酸甘油激发无关(p＞0.05)。随晕厥频次增加HUTT终点晕厥发作时间递增、心率递减、收缩压和舒张压递增(p＞0.05)。③HUTT阳性反应类型不存在性别、年龄、头晕与晕厥的差异(p＞0.05)。④HUTT阳性组血钾降低、血钙增加(p＜0.05),24h尿钠、尿钾明显增加(p＜0.05),FPG降低(p＜0.05),INS、CP、ALD降低,PRA、AⅡ增加(p＜0.05)。⑤晕厥组女性血钾、血磷降低、血钙增加(p＜0.01);FPG、ALD降低男性＞女性(p＜0.05),INS、CP降低男性＜女性(p＞0.05)。⑥晕厥组≥12岁组较＜12岁组的INS增加(p＜0.05)、CP增加(p＞0.05)。⑦血清电解质、24h尿电解质、每毫升尿电解质、血及尿电解质比值未见晕厥频次差异(p＞0.05);晕厥频次＜4次组较≥4次组FPG明显增加(p＜0.05),INS、CP稍增加(p＞0.05)。晕厥频次与INS及CP呈负相关(r=-0.635及-0.576)。⑧盐酸米多君与美托洛尔治疗前、后HUTT比较:治疗后较治疗前心率于HUTT各时间点盐酸米多君组稍增加,美托洛尔组稍降低(p＞0.05),两组收缩压稍降低(p＞0.05),舒张压在BHUT各时间点稍降低(p＞0.05),且美托洛尔组在SNHUT各时间点随倾斜时间延长呈现增加趋势(p＞0.05)。⑨根据临床主观疗效判断:23例VVS儿童口服盐酸米多君15-125天(平均53.52±40.20天),有效率73.91%(17/23),未见明显副反应;28例VVS儿童口服美托洛尔3-148天(平均38.61±32.68天),有效率89.29%(25/28),副反应出现率10.71%。两组疗效差异不明显(p＞0.05)。根据HUTT客观判断疗效:22例VVS儿童口服盐酸米多君15-125天(平均55.24±40.29天),有效率54.54%(12/22);24例VVS儿童口服美托洛尔3-148天(平均43.71±43.17天),有效率70.83%(17/24),两组疗效差异明显(p＜0.05)。HUTT终止时在盐酸米多君组治疗后晕厥发作时间在BHUT稍延长(p＞0.05),在SNHUT稍缩短(p＞0.05),心率、收缩压、舒张压稍降低(p＞0.05);美托洛尔组治疗后HUTT时晕厥发作时间稍缩短(p＞0.05);心率稍增加(p＞0.05)、收缩压、舒张压稍降低(p＞0.05)。⑩盐酸米多君组治疗后肝功能、肾功能、血脂、血电解质与尿电解质无明显变化(p＞0.05),FPG、PRA降低,INS、CP、AⅡ、ALD增加(p＞0.05)。结论①HUTT是儿童自主神经功能评价的有效工具。②VVS儿童自主神经功能紊乱,交感神经和副交感神经功能失衡。临床上部分儿童VVS病例以不明原因头晕发病。③HUTT导致的血流动力学变化与年龄、性别、倾斜角度、临床晕厥频次无关,倾斜终点血流动力学与是否使用硝酸甘油激发无明显关系,HUTT对儿童VVS无预测价值。④儿童HUTT推荐倾斜60°45min方案,硝酸甘油片舌下含化作为激发因子简便、安全、重复性好。⑤INS、CP可能参与了儿童VVS发病过程。⑥血、尿电解质与VVS基础状态无明显关系。⑦美托洛尔和盐酸米多君对儿童VVS主观临床疗效未见差异,用HUTT客观评价则美托洛尔有效率高,表明儿童VVS疗效判断HUTT优于主观效果。⑧盐酸米多君治疗VVS的机制可能与提高INS、CP,降低PRA,进一步增加ALD和AⅡ等有关,与血、尿电解质关系不密切。⑨盐酸米多君对儿童肝、肾功能、血脂代谢无明显影响,儿童应用安全。目的对儿童血管迷走性晕厥(VVS)进行直立倾斜试验(HUTT)诊断及其影响因素分析。方法2001年1月-2007年4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晕厥或晕厥先兆儿童301例,年龄3.08-18(平均11.82±3.16)岁,男125例,女176例。匹配健康儿童27例为对照。HUTT采用基础直立倾斜试验(BHUT)及舌下含化硝酸甘油倾斜试验(SNHUT)。检测各时间点心率、收缩压、舒张压,并将结果按以下分组比较:①晕厥组(n=301)与对照组(n=27);②晕厥儿童HUTT阳性组(n=174)与HUTT阴性组(n=127);③晕厥儿童HUTT阳性血管抑制型(n=139)与心脏抑制型+混合型(n=35);④晕厥组HUTT倾斜角度60°组(n=150)与倾斜角度70°组(n=151);⑤晕厥组按年龄分＜12岁组(n=125)与≥12岁(n=176)组;⑥晕厥组按性别分男(n=125)、女(n=176)两组;⑦晕厥组按临床晕厥发生频次(n=223)分Ⅰ组(晕厥发作仅1次,n=43)、Ⅱ组(晕厥发作2-4次,n=124)和Ⅲ组(晕厥发作≥5次,n=56);⑧不明原因头晕组(n=76)与不明原因晕厥组(n=225);⑨晕厥儿童BHUT阳性组(n=72)与SNHUT(n=102)阳性组。微机通过SPSS 11.5软件包进行统计学分析。结果①BHUT阳性率23.92%,SNHUT将阳性率提高到57.81%,未见硝酸甘油副反应。晕厥发作时间在BHUT为(22.54±10.82)min,SNHUT为(5.47±2.78)min,在反应类型之间无差异(p＞0.05)。②HUTT过程心率、收缩压、舒张压变化与受试者年龄、性别、倾斜角度、临床晕厥频次无明显关系(多数时间点表现为p＞0.05)。HUTT阳性终止时的血流动力学变化与是否使用硝酸甘油激发无关(p＞0.05)。随晕厥频次增加HUTT终点晕厥发作时间递增、心率递减、收缩压和舒张压递增(p＞0.05)。拟合预测晕厥频次的最优回归方程:晕厥频次(次)=1.553+0.204×年龄(岁)。③HUTT阳性反应类型不存在性别、年龄、头晕与晕厥的差异(p＞0.05)。④头晕组与晕厥组HUTT阳性率分别是63.16%和56.00%(p＞0.05),HUTT时心率头晕组大于晕厥组(多个时间点表现为p＜0.05或0.01),收缩压头晕组＜晕厥组(p＞0.05),舒张压头晕组＞晕厥组(p＞0.05)。HUTT倾斜终止时心率(p＜0.05)、收缩压(p＞0.05)、舒张压(p＞0.05)表现为头晕组＞晕厥组,晕厥发作时间头晕组＞晕厥组(p＞0.05)。结论①HUTT是儿童自主神经功能评价的有效工具。②VVS儿童自主神经功能紊乱,交感神经和副交感神经功能失衡。临床上部分儿童VVS病例以不明原因头晕发病。③HUTT导致的血流动力学变化与年龄、性别、倾斜角度、临床晕厥频次无关,倾斜终点血流动力学与是否使用硝酸甘油激发无明显关系,HUTT对儿童VVS无预测价值。④儿童HUTT推荐倾斜60°45min方案,硝酸甘油片舌下含化作为激发因子简便、安全、重复性好。目的探讨儿童血管迷走性晕厥(VVS)与血清胰岛素(INS)、C肽(CP)及血、尿电解质的初步关系。方法2004年6月-2007年4月在中南大学湘雅二医院晕厥专科门诊就诊或住院的儿童不明原因晕厥或先兆晕厥儿童(晕厥组,n=79)及健康儿童(对照组,n=11)进行HUTT检查。检测基础状态血清INS、CP、空腹血糖(FPG)、血浆肾素活性(PRA)、血管紧张素Ⅱ(AⅡ)、醛固酮(ALD)及血、尿电解质。晕厥组结果按下列分组比较:①与对照组比较;②HUTT不同反应类型比较;③HUTT不同反应结果比较;④不同性别比较;⑤不同年龄比较;⑥不同晕厥频次比较。微机通过SPSS 11.5软件包进行统计学分析。结果①晕厥组较对照组血钾降低、血钙增加(p＜0.05);24h尿量减少,24h尿钾、尿钠、尿氯、尿钙、尿磷增高,尿镁降低(p＞0.05);每毫升尿钠与尿钙增加(p＜0.05或0.01);血钠/血钾比值增加(p＜0.05);FPG、INS、CP、ALD降低,PRA、AⅡ增加(p＞0.05)。②晕厥儿童HUTT阳性组较HUTT阴性组和对照组血钾降低,血钙增高(p＜0.05);24h尿量增加(p＞0.05),24h尿钠、尿钾明显增加(p＜0.05),24h尿氯、尿钙、尿镁稍增加(p＞0.05);每毫升尿电解质变化与24h尿电解质变化趋势一致;血钠/血钾比值、尿钠/血肌酐比值增加(p＜0.05);FPG降低(p＜0.05),INS、CP、ALD降低(p＞0.05),PRA、AⅡ增加(p＞0.05)。③晕厥儿童HUTT阳性反应类型血管抑制型与心脏抑制型+混合型比较,血清电解质、24h尿电解质、每毫升尿电解质组间差异不明显(p＞0.05);PRA在血管抑制型组明显降低、心脏抑制型+混合型组明显增高(p＜0.01)。④性别比较:女性血钾、血磷降低、血钙增加(p＜0.01);女性24h尿钠、尿钾、尿镁增加(p＞0.05);每毫升尿电解质、电解质比例男女未见差异(p＞0.05);FPG、ALD降低男性＞女性(p＜0.05),INS、CP降低男性＜女性(p＞0.05)。⑤年龄比较:＜12岁组、≥12岁组与对照组比较血清电解质变化不明显(p＞0.05),24h尿量、尿钠、尿钾、尿钙、尿氯、尿磷表现为≥12岁组高于＜12岁组(p＞0.05),每毫升尿钠、尿氯变化趋势同24h尿电解质(p＞0.05),晕厥组≥12岁组较＜12岁组的INS增加(p＜0.05)、CP增加(p＞0.05)。⑥不同晕厥频次比较:血清电解质、24h尿电解质、每毫升尿电解质、血及尿电解质比值未见晕厥频次差异(p＞0.05);晕厥频次＜4次组较≥4次组FPG明显增加(p＜0.05),INS、CP稍增加(p＞0.05)。晕厥频次与INS及CP呈负相关(r=-0.635及-0.576)。预测晕厥频次的最优回归方程:晕厥频次(次)=4.565-0.213×胰岛素(mu/L)。结论①INS、CP可能参与了儿童VVS发病过程。②血、尿电解质与VVS基础状态无明显相关。目的探讨盐酸米多君与美托洛尔对儿童血管迷走性晕厥(VVS)的干预效果及其机制。方法2003年01-2007年04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晕厥儿童51例,男17例,女34例,年龄6.92-18岁(平均11.95±2.56岁),其中46例经过HUTT检查为阳性。在非药物治疗基础上,随机给予盐酸米多君(n=22,剂量为1.25mg/次,口服,2次/日,)和美托洛尔(n=24,剂量为1.0-1.5mg/(kg.d),口服,2-3次/日)治疗。将盐酸米多君组和美托洛尔组分别在用药前后进行血流动力学比较;盐酸米多君组还进行用药前后肝功能、肾功能、血脂、血清电解质、血清胰岛素(INS)、C肽(CP)、血浆肾素活性(PRA)、血管紧张素Ⅱ(AⅡ)、醛固酮(ALD)、24h尿电解质、每毫升尿电解质比较。微机通过SPSS 11.5软件包进行统计学分析。结果①盐酸米多君组与美托洛尔组治疗前后HUTT比较:治疗后较治疗前心率于HUTT各时间点盐酸米多君组稍增加,美托洛尔组稍降低(p＞0.05),两组收缩压稍降低(p＞0.05),舒张压在BHUT各时间点稍降低(p＞0.05),且美托洛尔组在SNHUT各时间点随倾斜时间延长呈现增加趋势(p＞0.05)。②临床主观效果判断:23例VVS儿童口服盐酸米多君15-125天(平均53.52±40.20天),有效率73.91%(17/23),未见明显副反应;28例VVS儿童口服美托洛尔3-148天(平均38.61±32.68天),有效率89.29%(25/28),副反应出现率10.71%。两组疗效差异不明显(p＞0.05)。根据HUTT客观判断疗效:22例VVS儿童口服盐酸米多君15-125天(平均55.24±40.29天),有效率54.54%(12/22);24例VVS儿童口服美托洛尔3-148天(平均43.71±43.17天),有效率70.83%(17/24)。两组疗效差异明显(p＜0.05)。HUTT终止时盐酸米多君组治疗后晕厥发作时间在BHUT稍延长(p＞0.05),在SNHUT稍缩短(p＞0.05),心率、收缩压、舒张压稍降低(p＞0.05);美托洛尔组治疗后HUTT时晕厥发作时间稍缩短(p＞0.05),心率稍增加(p＞0.05)、收缩压、舒张压稍降低(p＞0.05)。③盐酸米多君组用药后肝功能、肾功能、血脂、血尿电解质无明显变化(p＞0.05);FPG、PRA降低,INS、CP、AⅡ、ALD增加(p＞0.05)。结论①美托洛尔和盐酸米多君对儿童VVS临床主观疗效未见差异,用HUTT客观评价则美托洛尔有效率高,表明儿童VVS疗效判断HUTT优于主观效果。②盐酸米多君治疗VVS的机制可能与提高INS、CP,降低PRA,进一步增加ALD和AⅡ等有关,与血、尿电解质关系不密切。③盐酸米多君对儿童肝、肾功能、血脂代谢无明显影响,儿童应用安全。更多还原

【Abstract】 Objective To carry out head-up tilt table test evaluation and influential factor analysis in children with vasovagal syncope(VVS),to explore the initial relation between VVS of children and blood serum insulin,C-peptide,blood or uric electrolytes,and to study the intervention effect and mechanisms of midodrine hydrochloride and metoprolol in children with VVS.Methods The study involved a group of 301 chilren[125 males and 176 females,aged 3.08-18 years,mean(11.82±3.16)years)]with unexplained syncope or presyncope in out-patient clinic of syncope in the Second Xiangya Hospital of Central South University between January 2001and April 2007 and 27 healthy children as control groupe.To choose baseline head-up lilt table test(HUTT)and sublingual nitroglycerin tilt test(SNHUT)as empirical method and monitore heart rate,systolic pressure and diastolic pressure at all time points.To detect baseline blood serum insulin(INS),C-peptide(CP),fasting plasma glucose(FPG), plasma renin activity(PRA),angiotensinⅡ(ATⅡ),aldosterone(ALD) and blood or uric electrolytes for children with syncope(n=79)between June 2004 and April 2007.The children with syncope between January 2003 and April 2007 were selected and given randomly midodrine hydrochloride and metoprolol for treatment at the base of non-drug treatment.The computer did statistic analysis for the detected data by SPSS 11.5 software. Results①The positive rate was 23.92%in BHUT,it improved to 57.81%when cite SNHUT.Mean time of syncope episode were (22.54±10.82)min in BHUT and(5.47±2.78)min in SNHUT.There were no differences in response types between BHUT and SNHUT (p>0.05).②During HUTT,there was no significant relation between the change of heart rate,systolic pressure or diastolic pressure and subjects age,sex,tilt angles or clinical syncope frequency(p>0.05 at most of time points).The change of hemodynamics at the end of test in positive response was not related with whether or not stimulated by nitroglycerin (p>0.05).With frequency increasing,syncope episode time was increasing progressively,heart rate decreasing,and both systolic pressure and diastolic pressure increasing progressively(p>0.05).③There were no differences in sex,age,dizziness and syncope among response types of positive HUTT.④Among the group which was positive in HUTT,blood kalium decreased while blood calcium rose(p<0.05),as well as 24h uric natrium and uric kalium increased significantly(p<0.05),PRA and AⅡincreased(p>0.05),whereas FPG decreased(p<0.05),INS and CP and ALD also lowered(p>0.05).⑤Among the group with syncope,blood kalium and phosphonium decreased,blood calcium rose(p<0.01)in female;whereas FPG and ALD reduced(male > female,p<0.05),INS and CP decreased(male < female,p>0.05).⑥Among the grope with sycope,the patients above 12 years compared with below had the same increase in INS(p<0.05)and in CP(p>0.05).⑦No differences of syncope frequency was seen in serum electrolytes,24h uric electrolytes, electrolytes of each millilitre urine,and the ratio between serum and uric electrolytes(p>0.05);The groupe with syncope frequency below 4 times compared with above 4 times had a significant rise in FPG(p<0.05)and a slight increase in INS and CP(p>0.05).Negative correlation was present between syncope frequency and INS and CP(r=-0.635 and -0.576).⑧Comparing HUTT before and after midodrine hydrochloride and metoprolol:after treatment as compared to before,heart rate slightly increased in the group with midodrine hydrochloride treatment and decreased in the group with metoprolol treatment at all time points of HUTT(p>0.05),whereas both two groups had a slight decrease in systolic pressure(p>0.05)and in diastolic pressure at each time point of BHUT(p>0.05).Furthermore,metoprolol group present a trend of increase with tilt time lasting at every time points of SNHUT(p>0.05).⑨Judgement of clinical effect:In 23 children with VVS after administration of midodrine hydrochloride for 15-125 days(mean 53.52±40.20 days),effective rate were 73.91%(17/23),and side effect was not seen;In 28 children with VVS after administration of metoprolol for 3-148 days(mean 38.61±32.68 days),effective rate were 89.29% (25/28)and 10.71%cases had side effect.there were no significant differences between two groups on curative effect.To judge curative effect according to HUTT:In 23 children with VVS after administration of midodrine hydrochloride for 15-125 days(mean 55.24±40.29 days), effective rate were 54.54%(12/22);In 24 children with VVS after administration of metoprolol for 3-148 days(mean 43.71±43.17 days), effective rate were 70.83%(17/24).there were significant differences between two groups(p<0.05).At the end point of HUTT,the time of syncope episode after treatment of midodrine hydrochloride prolonged slightly in BHUT(p>0.05),while shorten slightly in SNHUT(p>0.05),as well as heart rate,systolic pressure and diastolic pressure decreased slightly(p>0.05).The time of syncope episode after treatment of metoprolol shorten slightly "in HUTT(p>0.05),as well as heart rate increased slightly(p>0.05),systolic pressure and diastolic pressure decreased slightly(p>0.05).⑩After treatment of midodrine hydrochloride,no marked changes were seen in liver function,renal function,blood fat and blood or uric electrolytes(p>0.05),whereas FPG and PRA decrease,at the same time INS,CP,AⅡand ALD all increased (p>0.05).Conclusion①HUTT is an available tool to evaluate children autonomic function.②In the children with VVS autonomic function disorder and sympathetic and parasympathetic function overbalance.In clinical,part of the children with VVS fall ill because of unexplained dizziness.③Hemodynamic variation caused by HUTT has no correlation with age,sex tilt angle and clinical syncope frequency,and hemodynamics at tilt end point do not relate obviously with whether or not stimulated by nitroglycerin.Thus HUTT has no predictive value for children VVS.④The program with 60°tilt angle and 45min time is preferred to children HUTT,and sublingual administration of nitroglycerin acted as provocative factor is convenient and safe and reproducible.⑤INS and CP take part in possibly development of VVS.⑥There is no significant relation between blood or uric electrolytes and baseline condition of VVS.⑦Differences are not seen between metoprolol and midodrine hydrochloride for children VVS in clinical effect,whereas,effective rate of metoprolol was larger in HUTT evaluating it,that show HUTT outweigh subjective effect in judgement of curative effect for children VVS.⑧The mechanisms of midodrine hydrochloride treatment for children VVS have possibly correlation with elevating INS and CP,lowering PRA and increasing ALD and AⅡ,but have no close relation with blood or uric electrolytes.⑨Midodrine hydrochloride has no marked effect on liver and renal function and blood-fat metabolism of children,so it is safe for children to use. Objective To evaluate and analysis influential factor of head-up tilt table test in children with vasovagal syncope(VVS).Methods The study involved a group of 301 chilren[125 males and 176 females,aged 3.08-18 years,mean(11.82±3.16)years]with unexplained syncope or presyncope in the Second Xiangya Hospital of Central South University between January 2001 and April 2007 and 27 healthy children as control group.To choose baseline head-up lilt table test(HUTT)and sublingual nitroglycerin tilt test(SNHUT)as empirical method.To monitore heart rate,systolic pressure and diastolic pressure at all time points and compare result of the children with syncope according to following groups:①Syncope group(n=301)and control group (n=27);②HUTT positive group(n=174)and HUTT negative group (n=127);③HUTT positive group with vasodepressor response (n=139)and those cardioinhibitory response + mixed response (n=139);④In syncope group,the group with 60°tilt angle in HUTT (n=150)and the group with 70°(n=151);⑤According to age,syncope group was divided into the group below 12 years(n=125)and the other above 12 years(n=176);⑥According to sex,syncope group was divided into male(n=125)and female(n=176)two groups;⑦According to syncope frequency,syncope was divided intoⅠgroup (frequency was 1 time,n=43),Ⅱgroup(frequency was 2-4 times,n=124) andⅢgroup(frequency=5 times,n=56);⑧The group with unexplained dizziness(n=76)and the group with unexplained syncope(n=225);⑨BHUT positive group(n=72)and SNHUT positive group(n=102). The computer did statistic analysis by SPSS 11.5 software.Results①The positive rate was 23.92%in BHUT,it improved to 57.81%when cite SNHUT.Mean time of syncope episode were (22.54±10.82)min in BHUT and(5.47±2.78)min SNHUT.There were no differences in response types between BHUT and SNHUT(p>0.05).②During HUTT,there was no conspicuous relation between the change of heart rate,systolic pressure or diastolic pressure and subjects age,sex, tilt angles or clinical syncope frequency(p>0.05 at most of time points). The change of hemodynamics at the end of test in positive response was not related with whether or not stimulated by nitroglycerin(p>0.05).With frequency increasing,syncope episode time was increasing progressively, heart rate decreasing by degrees,and both systolic pressure and diastolic pressure increasing progressively(p>0.05).The optimal regression equation for syncope frequency estimated:syncope frequency(times)= 1.553+0.204×age(years).③There were no differences in sex,age, dizziness and syncope among response types of HUTT.④HUTT positive rate of dizziness group and syncope group was 63.16%and 56.00% respectively,and during HUTT,heart rate was faster in the former than the latter(p<0.05 or 0.01 at most of time points),systolic pressure lower and diastolic pressure higher(p>0.05).At the end point of HUTT,heart rate(p<0.05),systolic pressure and diastolic pressure(p>0.05)present that dizziness group was larger than syncope group.The time of syncope episode in the former was longer than the latter(p>0.05).Conclusion①HUTT is an available tool to evaluate children autonomic function.②In the children with VVS autonomic function disorder and sympathetic and parasympathetic function overbalance.In clinical,part of the children with VVS fall ill because of unexplained dizziness.③Hemodynamic variation caused by HUTT has no correlation with age,sex,tilt angle and clinical syncope frequency,and hemodynamics at tilt end point do not relate obviously with whether or not stimulated by nitroglycerin.Thus HUTT has no predictive value for children VVS.④The program with 60°tilt angle and 45min time is preferred to children HUTT,and sublingual administration of nitroglycerin acted as provocative factoris convenient and safe and reproducible. Objective To explore the initial relation between VVS of children and blood serum insulin,C-peptide,blood and uric electrolytes.Methods HUTT was performed in a group of 79 children with unexplained syncope or presyncope(syncope group,n=79)and healthy children(control group,n=11)in out-patient clinic of syncope in the Second Xiangya Hospital of Central South University between June 2006 and April 2007.To detect baseline insulin(INS),C-peptide(CP),fasting plasma glucose(FPG),plasma renin activity(PRA),angiotensinⅡ(ATⅡ),aldosterone(ALD)and blood and uric electrolytes.To compare result of syncope group according to following groups:①with control group;②among various types of HUTT positive response;③among different results of HUTT positive response;④between males and females;⑤among different age;⑥among different syncope frequency. The computer did statistic analysis by SPSS 11.5 software.Results①Syncope compared with control group,blood kalium decreased while blood calcium rose(p<0.05);24h hypourocrinia,uric natrium,uric kalium,uric chlorinum,uric calcium and uric phosphonium increased while uric magnesium decreased(p>0.05);uric natrium and uric calcium of each millilitre urine increased(p<0.05 or 0.01);the ratio of blood natrium to blood kalium rose(p<0.05);FPG,INS,CP and ALD cut down,whereas PRA and AⅡincreased(p>0.05).②In the children with syncope,HUTT positive group compared with HUTT negative group and control group,blood kalium decreased while blood calcium rose(p<0.05);24h urinary volume raise(p>0.05),as well as 24h uric natrium and uric kalium increased significantly(p<0.05),and 24h uric chlorinum,uric calcium and uric magnesium increased slightly increased (p>0.05),there was the same trend of change between uric electrolytes of each millilitre urine and 24h ones;Both the ratio of blood natrium to blood kalium and that of uric natrium to serum creatinine increased (p<0.05);whereas FPG decreased(p<0.05),INS,CP and ALD also drop(p>0.05),but PRA and AⅡincreased(p>0.05).③In the children, HUTT positive reaction type with vasodepressor response(n=139) compared with those cardioinhibitory response + mixed response,no differences was seen in serum electrolytes,electrolytes of 24h uric each millilitre urine between two groups(p>0.05);PRA decreased obviously in the former while increased significantly in the latter(p<0.01).④Comparing males with females:female blood kalium and blood phosphonium decreased while blood calcium increased(p<0.01); differences were not seen in electrolytes of each millilitre urine and ratio of electrolytes between two groups(p>0.05);FPG and ALD drop(male > female,p<0.05)while INS and CP decreased(male < female,p>0.05).⑤Comparing different age:the groups below and above 12 years compared with control group,the change in serum electrolytes was not marked(p>0.05),24h urinary volume,uric natrium,uric kalium,uric calcium,uric chlorinum and uric phos- phonium were higher in the group above 12 years than below ones(p>0.05),there was the same trend of change between uric natrium and uric chlorinum of each millilitre and 24h uric electrolytes(p>0.05),the syncope group above 12 years compared with that below 12 years,INS(p<0.05)and CP(p>0.05) increased.⑥Comparing various syncope frequency:no differences of syncope frequency was seen in serum electrolytes,24h uric electrolytes, electrolytes of each millilitre urine,and the ratio between serum and uric electrolytes(p>0.05);the groupe with syncope frequency below 4 times compared with above 4 times had a significant rise in FPG(p<0.05)and a slight increase in INS and CP(p>0.05).negative correlation was present between syncope frequency and INS and CP(r=-0.635 and -0.576).the optimal regression equation for syncope frequency estimated:syncope frequency(times)= 4.565-0.213×insulin(mul/L).Conclusion①INS and CP take part in possibly development of VVS.②There is no significant relation between blood or uric electrolytes and baseline condition of VVS. Objective To study the intervention effect and mechanisms of midodrine hydrochloride and metoprolol in the children with vasovagal syncope(VVS).Methods In a group of 51 chilren[17 males and 34 females,aged 6.92-18 years,mean(11.95±2.56)years]with unexplained syncope in the Second Xiangya Hospital of Central South University between January 2003 and April 2007,there were 46 cases that were positive in HUTT. Given randomly midodrine hydrochloride[n=22,dose 1.0-1.5mg/(kg.d), po,Bid]and metoprolol[n-24,dose 1.0-1.5mg/(kg.d),po,2-3 times/day] for treatment at the base of non-drug treatment.To compare hemodynamics before and after treatment of midodrine hydrochloride and metoprolol;Also to compare liver function,renal function,blood fat and blood electrolytes,INS,CP,PRA,AⅡ,24h uric electrolytes and electrolytes of each millilitre urine before and after treatment of midodrine hydrochloride.The computer did statistic analysis by SPSS 11.5 software.Results①Comparing HUTr before and after midodrine hydrochloride and metoprolol:after treatment as compared to before, heart rate slightly increased in the group with midodrine hydrochloride treatment and decreased in the group with metoprolol treatment at all time points of HUTT(p>0.05),whereas both two groups had a slight decrease in systolic pressure(p>0.05)and in diastolic pressure at each time point of BHUT(p>0.05).Furthermore,the latter present a trend of increase with tilt time lasting at every time points of SNHUT(p>0.05).②Judgement of clinical effect:In 23 children with VVS after administration of midodrine hydrochloride for 15-125 days(mean 53.52±40.20days),effective rate were 73.91%(17/23),and side effect was not seen;In 28 children with VVS after administration of metoprolol for 3-148 days(mean 38.61±32.68 days),effective rate were 89.29% (25/28)and 10.71%cases had side effect.There were no significant differences between two groups on curative effect.To judge curative effect according to HUTT:In 23 children with VVS after administration of midodrine hydrochloride for 15-125 days(mean 55.24±40.29 days), effective rate were 54.54%(12/22);In 24 children with WS after administration of metoprolol for 3-148 days(mean 43.71±43.17 days), effective rate were 70.83%(17/24).There were significant differences between two groups(p>0.05).At the end point of HUTT,the time of syncope episode after treatment of midodrine hydrochloride prolonged slightly in BHUT(p>0.05),while shorten slightly in SNHUT(p>0.05),as well as heart rate,systolic pressure and diastolic pressure decreased slightly(p>0.05).The time of syncope episode after treatment of metoprolol shorten slightly during HUTT(p>0.05),heart rate increased slightly(p>0.05),whereas systolic pressure and diastolic pressure decreased slightly(p>0.05).③After treatment of midodrine hydrochloride,no marked changes were seen in liver function,renal function,blood fat and blood or uric electrolytes(p>0.05),whereas FPG and PRA decrease,at the same time INS,CP,AⅡand ALD all increase (p>0.05).Conlusion①Differences are not seen between metoprolol and midodrine hydrochloride for children VVS in clinical effect,whereas, effective rate of metoprolol is larger in HUTT evaluating it,that show HUTT outweigh subjective effect in judgement of curative effect for children with VVS.②The mechanisms of midodrine hydrochloride treatment for children with VVS have possibly correlation with elevating INS and CP,lowering PRA and increasing ALD and AⅡ,but has no close relation with blood or uric electrolytes.③Midodrine hydrochloride has no marked effect on liver and renal function and blood-fat metabolism of children,so it is safe for children to use.更多还原