Pediatric patients head-up-tilt-test with pharmacological challenge, it is safe? / Mesa inclinada en pacientes pediátricos con reto farmacológico, ¿es seguro?

Abstract Syncope in pediatrics represents an important cause of visits to the emergency units. For this reason, excluding a cardiac or malignant origin is essential at the time of the initial approach to determine what is the next step in management, or if they need to be referred to a pediatric cardiologist and/or electrophysiologist. Vasovagal syncope is the most frequent cause of syncope in pediatrics, in which a detailed clinical history is enough to make the diagnosis. If no diagnosis is concluded by the history, or if it is necessary to define the hemodynamic response of the patients, the head-up-tilt-test is indicated; this will trigger syncope due to an orthostatic stress caused by the angulated table (passive phase). If a negative response remains, it can be followed by a pharmacologic challenge to trigger the hemodynamic response, which is still controversial in pediatrics. The pharmacologic challenge increases the sensitivity with a slight reduction in test specificity. Although there is not a specific drug for the challenge in pediatric patients yet, the most commonly drugs used are nitrates and isoproterenol, the latter related to a great number of adverse effects. Sublingual administration of nitrates in the challenge has been proven to be ideal, effective, and safe in this specific age group. The aim of this article is to make a literature search to demonstrate the effectiveness and safety of the pharmacologic challenge during the head-up-tilt-test in pediatrics, emphasizing a study conducted at the National Institute of Cardiology with isosorbide dinitrate.

Resumen El síncope en edades pediátricas representa una causa importante en las visitas a unidades de urgencias, por lo que excluir un origen cardíaco o maligno es fundamental al momento del abordaje inicial para determinar la conducta a seguir o la necesidad de derivar al cardiólogo pediatra o electrofisiólogo. El síncope vasovagal (SVV) es la causa más frecuente de síncope en pediatría, para cuyo diagnóstico basta una historia clínica detallada. Cuando ésta no es suficiente para determinar el diagnóstico de síncope reflejo o es necesario definir el tipo de respuesta que lo origina, está indicada una prueba de mesa inclinada que produce un estrés ortostático por la angulación y ello desencadena un síncope (fase pasiva). En pruebas no concluyentes está indicado un reto farmacológico para precipitar la respuesta hemodinámica, pero aún es un tema de controversia en edades pediátricas. El reto farmacológico incrementa la sensibilidad de la prueba, con una ligera reducción de la especificidad. Si bien no existe todavía un medicamento específico para la población pediátrica, los más empleados son los nitratos y el isoproterenol, este último relacionado con un mayor número de efectos adversos. La administración sublingual de los nitratos utilizados ha demostrado ser ideal, efectiva y segura en los pacientes pediátricos. El objetivo del artículo es realizar una revisión de las publicaciones médicas que demuestran la efectividad y seguridad del reto farmacológico durante la prueba de mesa inclinada en pacientes pediátricos, con énfasis en un estudio conducido en el Instituto Nacional de Cardiología con dinitrato de isosorbida (DNIS).

Changes in ventricular late potentials in children and adolescents with postural tachycardia syndrome / 中华实用儿科临床杂志

Objective@#To investigate the changes in ventricular late potentials (VLP) in children and adolescents with postural tachycardia syndrome (POTS).@*Methods@#One hundred and forty-four children and adolescents diagnosed as POTS by using the head-up tilt test (HUTT) in Second Xiangya Hospital of Central South University from January 2012 to March 2019 were selected as POTS group, their age ranged 4 to 16 years old[(11.03±2.34)years old], there were 65 boys and 79 girls.Ninety-one healthy children and adolescents matched by age and gender[aged 4-16 (11.22±1.68) years old, there were 50 boys and 41 girls]were selected as the healthy control group.VLP was measured by SR-1000A ECG automatic analyzer (Boai, Guangdong, China).@*Results@#Compared with the healthy control group, the prevalence of positive VLP in the POTS group increased [ 11.1%(16/144 cases)vs.1.1%(1/91cases)], and the difference was statistically significant(χ2= 6.904, P<0.01); the heart rate in the POTS group increased compared with that in the healthy control group[82.0 (74.0-95.0) times/min vs.78.0 (71.0-86.0) times/min], and the difference was statistically significant(Z=-2.265, P<0.05); the low-amplitude signal(LAS40) in the POTS group prolonged compared with that in the healthy control group[23.0 (17.0-31.0) μV vs.19.0 (13.0-25.0) μV], and the difference was statistically significant(Z=-4.114, P<0.01); root mean square amplitude(RMS40) increased compared with that in the healthy control group[61.3 (34.4-79.1) ms vs.52.0 (38.8-64.5) ms], and the difference was statistically significant (Z=-2.469, P<0.05). There was no statistically significant difference in total QRS time (TQRS) between 2 groups [86.0 (76.0-97.5) ms vs.87.0 (81.0-94.0) ms, Z=-0.007, P>0.05].@*Conclusions@#The positive rate of VLP is increased of children and adolescents with POTS.It suggests that there is an abnormal cardiac electrical activity in children and adolescents with POTS.

Changes in ventricular late potentials in children and adolescents with postural tachycardia syndrome / 中华实用儿科临床杂志

Objective To investigate the changes in ventricular late potentials (VLP) in children and adolescents with postural tachycardia syndrome (POTS).Methods One hundred and forty-four children and adolescents diagnosed as POTS by using the head-up tilt test (HUTT) in Second Xiangya Hospital of Central South University from January 2012 to March 2019 were selected as POTS group,their age ranged 4 to 16 years old [(11.03 ± 2.34) years old],there were 65 boys and 79 girls.Ninety-one healthy children and adolescents matched by age and gender [aged 4-16 (11.22 ± 1.68) years old,there were 50 boys and 41 girls] were selected as the healthy control group.VLP was measured by SR-1000A ECG automatic analyzer (Boai,Guangdong,China).Results Compared with the healthy control group,the prevalence of positive VLP in the POTS group increased [11.1％ (16/144 cases)vs.1.1％ (1/91 cases)],and the difference was statistically significant(x2=6.904,P ＜ 0.01);the heart rate in the POTS group increased compared with that in the healthy control group [82.0 (74.0-95.0) times/min vs.78.0 (71.0-86.0) times/min],and the difference was statistically significant (Z =-2.265,P ＜ 0.05);the low-amplitude signal (LAS40) in the POTS group prolonged compared with that in the healthy control group[23.0 (17.0-31.0) μV vs.19.0 (13.0-25.0) μV],and the difference was statistically significant (Z =-4.114,P ＜ 0.01);root mean square amplitude(RMS40) increased compared with that in the healthy control group [61.3 (34.4-79.1) ms vs.52.0 (38.8-64.5) ms],and the difference was statistically significant (Z =-2.469,P ＜ 0.05).There was no statistically significant difference in total QRS time (TQRS) between 2 groups [86.0 (76.0-97.5) ms vs.87.0 (81.0-94.0) ms,Z =-0.007,P ＞ 0.05].Conclusions The positive rate of VLP is increased of children and adolescents with POTS.It suggests that there is an abnormal cardiac electrical activity in children and adolescents with POTS.

The etiological distribution and clinical features of autonomic neuromediated syncope in children and adolescents:single center 15 years retrospective analysis / 中国小儿急救医学

Objective To retrospectively analyze the etiological distribution and clinical features of autonomic neuromediated syncope ( NMS) in children and adolescents in single center for 15 years. Methods There were 3182 cases of children and adolescents[aged from 2 to 18 years,the average age(10. 75 ± 3. 13) years] with unexplained syncope or symptoms of presyncope ( including unexplained dizziness,headache,chest tightness,chest pain,sigh,heart palpitations,etc),who came from children syncope outpatient department or inpatient department in the Second Xiangya Hospital,Central South University from September 2000 to October 2015. Of all 3182 cases,1649 cases were male,1533 cases were female. All subjects underwent detailed history collection,careful physical examination,12-lead electrocardiogram,Holter ECG,chest X-ray,echocardiography, EEG and head CT or MRI,blood biochemical examination (including fasting glucose,myocardial enzymes) and were eliminated organic disease of heart,lung,brain and so on,the cause of syncope was not still clear. The head-up tilt test ( HUTT ) was performed after the patient or / and the guardian written informed consent obtained. Results (1)HUTT positive rate was 47. 05％ (1497/3182). Causes for vasovagal syncope in turn was 42. 99％ ( 1368/3182 ) , postural orthostatic tachycardia syndrome was 2. 55％ ( 81/3182 ) , orthostatic hypertension was 0. 79％ (25/3182),orthostatic hypotension was 0. 06％ (2/3182). (2)The clinical symp-toms in NMS of different etiologies were mainly syncope,dizziness,chest tightness,chest pain,headache,heart pal-pitations. Conclusion The causes of NMS in children are vasovagal syncope and postural orthostatic tachycardia syndrome,and the clinical features are syncope,dizziness,chest tightness,chest pain,headache,heart palpitations.

Comparison of curative effect and serum electrolytes between different oral rehydration salts in treatment of neurally mediated syncope children / 中南大学学报(医学版)

Objective:To compare the curative effect and the changes of serum electrolytes between oral rehydration salts (ORS) Ⅰ and ORS Ⅲ treatment in neurally mediated syncope children.Methods:The children with the symptom of unexplained syncope and pre-syncope were collected in Second Xiangya Hospital from May 2014 to May 2017.After head-up tilt test (HUTT),their serum electrolytes levels were examined.Children who were positive in the HUTT received ORS (ORS Ⅰ or ORS Ⅲ) and health education.Subjects were randomly divided into an ORS Ⅰ group (n=27) and an ORS Ⅲ group (n=49).Results:There was no statistical significance in sex,age,height,body mass,initial diagnosis and re-diagnosis interval between the 2 groups (P＞0.05);the total efficiency after ORS Ⅲ and ORS Ⅰ treatment were 79.59％ and 62.96％,respectively,with no statistical significance (x2=2.483,P＞0.05);the HUTT negative conversion rate after ORS Ⅲ and ORS Ⅰ treatment were 51.02％ and 48.16％,respectively,with no statistical significance (x2=0.058,P＞0.05);before treatment,the serum sodium [(140.20±2.26) mmol/L vs (138.39±2.72) mmol/L;t=2.856,P＜0.05] in the ORS Ⅲ group was higher than that in the ORS Ⅰ group,the serum phosphorus [(1.46±0.19) mmol/L vs (1.65±0.29) mmol/L;t=3.146,P＜0.05] in the ORS Ⅲ group was lower than that in the ORS Ⅰ group;after treatment,the serum sodium [(140.31±2.01) mmol/L vs (138.88±2.08) mmol/L;t=2.692,P＜0.05] and serum calcium [(2.31±0.09) mmol/L vs (2.24±0.11) mmol/L;t=2.696,P＜0.05] in the ORS Ⅲ group were higher than those in the ORS Ⅰ group,the serum phosphorus [(1.45±0.16) mmol/L vs (1.61±0.25) mmol/L;t=3.128,P＜0.05] in the ORS Ⅲ group was lower than that in the ORS Ⅰ group;after ORS Ⅲ treatment,there was no statistical significance in serum electrolytes between HUTT positive group and HUTT negative group (P＞0.05);after ORS Ⅰ treatment,the serum calcium [(2.29±0.10) mmol/L vs (2.19±0.10) mmol/L;t=2.501,P＜0.05]and serum phosphorus [(1.71±0.24) mmol/L vs (1.50±0.21) mmol/L;t=2.392,P＜0.05] in HUTT positive group were higher than those in HUTT negative group.There was no statistical significance in serum sodium,potassium,magnesium,and chloride (P＞0.05);there was no statistical significance in serum electrolytes between pre-treatment and post-treatment in the ORS Ⅰ group and the ORS Ⅲ group (P＞0.05);there was no statistical significance in serum electrolytes between vasovagal syncope and postural orthostatic tachycardia syndrome in the ORS Ⅰ group and the ORS Ⅲ group before ORS treatment (P＞0.05).Conclusion:The ORS Ⅲ and ORS Ⅰ have the similar efficacy in the treatment of children with neurally mediated syncope.ORS Ⅲ is easier to be accepted by children than ORS Ⅰ,with better compliance.

Relationship between unexplained palpitation in children and head-up tilt test / 中南大学学报(医学版)

Objective:To explore the relationship between unexplained palpitation in children and head-up tilt test (HUTT).Methods:A total of 142 children with the main symptom of unexplained palpitation were admitted to the Specialist Out-Patient Clinic of Children's Cardiovascular Disease from Sept.2008 to Feb.2017 in the Second Xiangya Hospital,Central South University.Among them,63 cases were male,79 cases were female,with the mean age of (10.12±2.88) years old.The detailed history,physical examinations,conventional 12 electrocardiogram,chest X-ray,echocardiography,myocardial enzymes and thyroid function were all examined.The disorders of heart disease,systemic disease and drug effect were ruled out.The HUTT inspection was then given to them.Results:Among the 142 palpitation cases,79 cases were HUTT positive (55.6％) and 63 cases were HUTT negative (44.4％).The age in HUTT positive patients was older than that in HUTT negative patients (P＜0.05),with no significant difference in gender (P＞0.05).There were three types of hemodynamic changes in HUTT positive patients.Among them,38 cases were postural orthostatic tachycardia syndrome (48.1％),36 cases were the vasovagal syncope vasodepressive type (45.6％) and 5 cases were the vasovagal syncope mixed type (6.3％).There were no hemodynamic types for vasovagal syncope cardioinhibitory type,orthostatic hypotension and orthostatic hypertension.Conclusion:Among the clinically unexplained palpitations children,more than half are caused by unbalanced autonomic nervous function.HUTT can help clear the cause of unexplained palpitations.

Several questions of head-up tilt test in the Children with neurally mediated syncope / 国际儿科学杂志

Neurally mediated syncope (NMS)is common in pediatric emergency and intensive care unit.Head-up tilt test(HUTT)has been widely used as an valuable diagnostic tools for NMS,while the results would be affected by multiple factors.Controversies still exist on issues such as the influence factors of positive rate,complication and clinical predictions of the HUTT.In this review,several problems in the application of HUTT in NMS of children are reviewed.

The predictive value of orthostatic intolerance symptoms in children and adolescents to the head-up tilt test results / 中国小儿急救医学

Objective To explore the predictive value of orthostatic intolerance( OI) symptoms in children and adolescents to the head-up tilt test( HUTT) results. Methods A total of 274 children or adoles-cents complaining with the following symptoms were chosen:unexplained syncope,dizziness,headache,chest tightness,chest pain,sigh,and so on. The 274 cases included 141 males and 133 females aging from 5 to 18 years old with a mean age of (11. 8 ± 2. 7) years. All the cases in this study came from the syncope special-ized clinic or inpatient department of the Second Xiangya Hospital,Central South University,from July 2016 to March 2017. All the patients had been asked in detail about the history, physical examination, routine 12-lead electrocardiogram,chest X-ray,echocardiogram,electroencephalogram,head computer tomography or magnetic resonance imaging,blood and a series of checks to exclude organic heart,brain,lung diseases. Each patient was asked to finish OI questionnaire and HUTT. Results All 274 patients were divided into HUTT negative group(n=151) and HUTT positive group(n=123). Dizziness(65. 3％) was the most common OI symptom,followed by syncope(50. 7％),blurred vision or amaurosis(45. 6％) and fatigue(43. 4％). There were significant differences in the prevalence of palpitation,headache,profuse perspiration,blurred vision or amaurosis,chest tightness,dizziness,gastrointestinal symptoms( nausea,vomiting,abdominal pain,abdominal distension) and syncope between HUTT positive and HUTT negative groups ( P<0. 05 ) . According to the multivariate Logistic regression analysis,these eight OI symptoms could affect the results of HUTT to some extent(odds ratio>1). Conclusion The symptoms of palpitation,headache,profuse perspiration,blurred vi-sion,chest discomfort,dizziness,gastrointestinal symptoms( nausea,vomiting,abdominal pain,abdominal dis-tension) and syncope can impact the positive results of HUTT.

Diagnostic value of head-up tilt test in patients with cough syncope / 重庆医学

Objective To investigate the diagnostic value of head-up tilt test (HUT) in cough syncope (CS).Methods Forty-seven outpatients or inpatients with CS and 79 patients with suspected vasovagal syncope(SVVS) due to syncope history in our hospital from January 2011 to May 2015 served as the observation group and control group respectively.HUT was performed in the two groups.The cough response during HUT,changes of systolic pressure and diastolic pressure caused by cough,HUT positive results and hemodynamic type were observed,Results In the observation group,4 cases(8.51％) were cough caused syncope,26 cases (55.32 ％) were presyncope and 17 cases (36.17 ％) had no symptoms,while 79 cases in the control group had no symptoms,the differences were statistically significant (P＜ 0.05).The total positive rate of cough response in the observation group was 63.83％,and the specificity was 100.00％.The systolic blood pressure had statistical difference between the two groups(.P＜0.05).The diastolic pressure had statistical difference between the cases of non-symptoms with the cases of syncope and cases of presyncope in the observation group (P＜0.05),but had no statistical difference compared with the cases of non-symptoms in the control group(P＞0.05).The heart rate(HR) had no statistical difference among various groups(P＞0.05).The HUT positive rate in the observation group was lower than that in the control group(P＜0.05).The hemodynamic type had no statistical difference between the two groups(P＞0.05).Conclusion Severe coughing during HUT may cause the blood pressure decrease,induces syncope or presyncope,can increase the diagnostic sensitivity of CS patients,which is very useful in the suspected diagnosis of CS patients,especially for CS patients with a unclear history.

Diagnostic value of head-up tilt test in patients with cough syncope / 重庆医学

Objective To investigate the diagnostic value of head-up tilt test (HUT) in cough syncope (CS).Methods Forty-seven outpatients or inpatients with CS and 79 patients with suspected vasovagal syncope(SVVS) due to syncope history in our hospital from January 2011 to May 2015 served as the observation group and control group respectively.HUT was performed in the two groups.The cough response during HUT,changes of systolic pressure and diastolic pressure caused by cough,HUT positive results and hemodynamic type were observed,Results In the observation group,4 cases(8.51％) were cough caused syncope,26 cases (55.32 ％) were presyncope and 17 cases (36.17 ％) had no symptoms,while 79 cases in the control group had no symptoms,the differences were statistically significant (P＜ 0.05).The total positive rate of cough response in the observation group was 63.83％,and the specificity was 100.00％.The systolic blood pressure had statistical difference between the two groups(.P＜0.05).The diastolic pressure had statistical difference between the cases of non-symptoms with the cases of syncope and cases of presyncope in the observation group (P＜0.05),but had no statistical difference compared with the cases of non-symptoms in the control group(P＞0.05).The heart rate(HR) had no statistical difference among various groups(P＞0.05).The HUT positive rate in the observation group was lower than that in the control group(P＜0.05).The hemodynamic type had no statistical difference between the two groups(P＞0.05).Conclusion Severe coughing during HUT may cause the blood pressure decrease,induces syncope or presyncope,can increase the diagnostic sensitivity of CS patients,which is very useful in the suspected diagnosis of CS patients,especially for CS patients with a unclear history.

Electrocardiogram Characteristics of Suspected Vasovagal Syncope Patients With Positive Head-Up Tilt Test / 中国循环杂志

Objective: To investigate the dynamic electrocardiogram (ECG) changes of head-up tilt test in patients with suspected vasovagal syncope. Methods: A total of 502 outpatients of our hospital with suspicious vasovagal syncope from 2015-08 to 2016-12 were enrolled. All patients received head-up tilt test with synchronization of 12 lead ECG. Based on head-up tilt test result, the patients were divided into 2 groups: Positive group,n=244 and Negative group,n=258. The P wave duration, corrective QT (QTc) duration and P wave axis in ECG were compared between 2 groups. Results: Compared with Negative group, Positive group had the longer P wave duration (95.65±38.50) ms vs (88.61±17.09) ms,P<0.05; P wave axis was right shifted before syncope (69.87±18.18)° vs (66.82±16.51)° , while left shifted during syncope (62.87±25.39)° vs (68.47±15.30)° and after syncope (56.87±22.45)° vs (68.49±16.35)°, allP<0.05; the shorter QTc duration before syncope (418.69±92.35) ms vs (435.76±59.29) ms,P<0.05. Conclusion: The patients with vasovagal syncope had some speciifc ECG features during head-up tilt test including P wave duration, P wave axis and QTc duration, those may play certain forewarning function for vasovagal syncope onset.

Head-up tilt test induced shortened QT interval:a case report and literature review / 临床儿科杂志

Objective To explore the cause of secondary QT interval shortening. Method The data of a child with vasovagal syncope and cardiac depression in whom shortened QT interval was induced in head-up tilt test (HUTT) was analyzed retrospectively, and the related literatures were reviewed. Result A 12-year-old boy visited for fainting when brushing his teeth in the morning. ECG showed sinus bradycardia, heart rate at 55 times /min and normal QT and QTc interval. Dynamic electrocardiogram showed sinus rhythm, mean heart rate at 70 times/min, atrial anterior contraction 3 times, normal mean QT and mean QTc. UCG showed approximately normal heart structure and the left ventricular systolic function. There was no abnormality in EEG and cranial CT. His fasting blood glucose was 5.2 mmol/L. The basal tilt test was positive with vasovagal syncope and cardiac depression. During the tilt table test, Holter monitoring showed that sinus arrest occurred in the child when upright tilt for16 min, and then fainted. Time of sinus arrest was 2.9 s and 11.4 s, respectively, and artificial chest compressions were performed. The QT interval was shortened (QT=330 ms), and so was QTc interval (QTc=320 ms). The ratio of QT/QTp was 78% (the lower limit of normal QT interval was 88% of QTp) before sinus arrest occurred. Conclusion Increased vagal tone may induce QT interval shortening.

Analysis of the results of head-up tilt test in syncope children / 中华实用儿科临床杂志

Objective To explore the familial genetic characteristics of twins syncope in children.Methods Four pairs of twins with unexplained dizziness,headache,chest tightness,chest pain,pre-syncope and syncope were received head-up tilt test (HUTT) and family history of syncope were inquired.The age,gender,clinical manifestations were analyzed and the HUTT hemodynamic response were performed,and interviewed via telephone.Results The onset age of 4 pairs of twins ranged from 7 to 12 years old,less than 15 years,the median age of the first syncope episodes.Cause of syncope was primarily standing(4/5 cases),2 pairs had syncope positive family history.HUTT hemodynamic response type was mainly vasodepressor syncope (4/5 cases).HUTT result and hemodynamic response type were not completely consistent in the same twins.One case of the first twins was vasodepressor syncope and postural orthostatic tachycardia syndrome.One case of the second twins was vasodepressor syncope,while the other was negative.The third twins were vasodepressor syncope.The fourth twins were negative.HUTT results of the 4 twins were diverse,indicating that environment,psychological factors may get involved in syncope episodes.Conclusions The familial genetic factors of the children with syncope may play an important role in the young age group.Environment and psychological factors may be induce syncope attack.HUTT results of twins are diverse.HUTT result and hemodynamic response type can be inconsistent in the same twin.

Research advance in children's orthostatic hypertension / 中华实用儿科临床杂志

Orthostatic hypertension (OHT) is defined as an increase in blood pressure from supine to orthostatic position.Its mechanism involves a greater venous pooling in the lower extremities,sympathetic activation,change of neurohumoral factors and hypersensitivity of baroreflex.The diagnosis of OHT mainly depends on head-up tilt test.OHT is closely related to hypertension,coronary artery diseases and asymptomatic cerebral infarction.It might be a new predictor of cardiovascular and cerebrovascular diseases and a long-term marker for evaluating target organs damage in hypertension.Studies about OHT in children are rare.To some extent,blood pressure exists tracking phenomenon,further study of OHT in children is beneficial to predict the risk of cardiovascular and cerebrovascular disease and evaluate the target organ damage in adulthood.

The relationship between the hemodynamic changes in head-up tilt test and the height, body quality and body mass index in children / 中国小儿急救医学

Objective To explore the relationship between the hemodynamic changes in head-up tilt test(HUTT) and the height,body quality and body mass index in children.Methods We choosed 1906 cases of unexplained syncope,headache,dizziness in children who came from Children Syncope Outpatient in the Second Xiangya Hospital of Central South University from Jan.2000 to Aug.2012,Male 964 cases and female 942 cases.Their ages were 2 to 17.92 years old.The average age was 10.84 ± 2.97 years old.The height and body mass in children was measured,BMI was calculated.After obtain written informed consent subjects or guardian,the HUTT was carried.According to the result of HUTT and reaction type,the children were divided into HUTT negative group,orthostatic tachycardia syndrome(POTS) group,vasovagal syncope (VVS) vascular inhibitory type group,VVS heart inhibited type group,the VVS mixed group.Results Compared to the HUTT negative group,the age increased in POTS group and VVS vascular inhibitory group and VVS mixed group(P ＜ 0.05),height and body quality and body surface area increased in POTS group and VVS vascular inhibitory group and VVS mixed group(P ＜ 0.01).Compared to POTS group,body quality and body surface area reduced in VVS vascular inhibitory group and VVS mixed group(P ＜ 0.05).VVS heart inhibitory group was no statistically significant difference compared with the other groups (P ＞ 0.05).Conclusion There is a certain relationship between the hemodynamic changes in HUTT and the height,body quality and BMI in children.

Effect of Age and Gender on Head-up Tilt Test for Diagnosing the Patients With Suspected Vasovagal Syncope / 中国循环杂志

Objective: To explore the effect of age and gender on head-up tilt test (HUTT) for diagnosing the patients with suspected vasovagal syncope (VVS). Methods: A total of 1223 patients who received HUTT in our hospital from 2008-08 to 2012-12 were studied. The patients were from 7 to 79 years of age and divided into 4 groups. Group 1, the patients≤20 years of age, n=145, Group 2, the patients at (21-40) years, n=375, Group 3, the patients at (41-60) years, n=584 and Group 4, the patients>60 years, n=119. The HUTT comprised a 30 min basic phase and 20 min sublingual nitroglycerin provocation phase. According to ECG and blood pressure changes, the HUTT positive patients included vasodepressor type, cardio-inhibitory type and mixed type. Results: The overall positive rate of HUTT was 51%(624/1223) and the female was higher than male, (60.1%vs 39.9%), P=0.001. The positive rates in 4 age groups were at 68.3%, 49.1%, 48.6% and 47.9% respectively. In HUTT positive patients, there were 51.4% (321/624) patients with mixed type of VVS, 28.7% (179/624) with vasodepressor type of VVS and 19.9% (124/624) with cardio-inhibitory type of VVS. The positive HUTT reaction was inlfuenced by the age as in male:x2=15.65, P=0.016 and in female:x2=18.84, P=0.004. For basic phase of HUTT, there were 74.8%of positive reactions started at 22.5 (17.5-27.5) min of the test without age difference, P>0.05;for sublingual nitroglycerin provocation phase of HUTT, there were 81.9%positive reactions started at 7.5 (5-10) min and the female was earlier than male (7.5 vs 10) min, P=0.004. Conclusion: There were age and gender differences for HUTT diagnosing the patients with VVS for their positive rate, type and starting time.

Correlation Between Orthostatic Symptoms and Autonomic Parameters During the Head-Up Tilt Test

BACKGROUND: The aims of the present study were to identify the orthostatic symptoms occurring during the head-up tilt (HUT) test and to compare the autonomic parameters in patients with and without symptoms during the HUT test. METHODS: We retrospectively collected autonomic data from patients presenting with autonomic symptoms including orthostatic dizziness over a 1-year period. A standardized battery of autonomic tests was performed, including the HUT test, Valsalva maneuver (VM), heart rate (HR) deep breathing test, and quantitative sudomotor axon reflex test (QSART) using Finometer devices to record the beat-to-beat blood pressure (BP) and HR response. We also investigated the patients' symptoms during the HUT test and compared the autonomic parameters between patients with and without orthostatic symptoms. RESULTS: In total, 898 patients who submitted to autonomic function tests were included in this study. Of these, 17% (157/898) complained of various kinds of symptoms during tilting, while the remainder denied any symptoms. Patients complained of atypical symptoms, such as leg or back pain, tingling sensation in the leg, and difficulty breathing or chest tightness, as well as typical orthostatic symptoms. The BP decrease and the HR increase during the HUT test were greater in the symptomatic group. A prolonged pressure recovery time during VM, a lower sweat output during QSART, and a higher composite autonomic severity score were observed in the symptomatic group. CONCLUSIONS: Approximately one-fifth of the patients complained of symptoms during the HUT test, and those symptoms were strongly correlated with the autonomic parameters suggestive of impaired compensative mechanisms in response to a BP fall.

Related factors of head up tilt test in children with vasovagal syncope / 中国医师进修杂志

Objective To summarize the risk factors of head up tilt test (HUTT) in children with vasovagal syncope,and provide theoretical reference for the diagnosis of vasovagal syncope.Methods The total of 340 children with headache and syncope were included in the study,all the cases received HUTT,including basic tilt table test and sublingual nitroglycerin test.And they were divided into HUTT positive group and HUTT negative group according to the results.The clinical information of two groups was analyzed by multivariate Logistic regression to summarize risk factors.Results The frequency of syncope in HUTT positive group was 2.3 ± 1.1,significantly higher than that in HUTT negative group (0.7 ±0.2),chest tightness and blurred vision ratios were significandy higher than those in HUTT negative group (84/186,48/186 vs.34/154,23/154).Single factor analysis showed,older than 12 years old,female,blurred vision,with history and genetic history of syncope,numerous of syncope,chest tightness,fatigue were related factors as positive results for HUTT.Multivariate Logistic regression analysis showed,older than 12 years old,female,with history and genetic history of syncope were independent risk factors of positive HUTF.β was 0.744,1.126,1.312,0.514 respectively,95％ CI was 1.132-5.968,1.985-5.040,1.366-9.677,1.683-6.532 respectively.Conclusion Age,gender,family history,history of syncope have important significance to predict HUTT results.

Relationship between unexplained sighs in children and head-up tilt test / 中华实用儿科临床杂志

Objective To explore the relationship between unexplained sighs in children and head-up tilt test (HUTT).Methods Ninety-six cases of children with the main symptom of unexplained sighs were received at Specialist Out-Patient Clinic of Children's Syncope from May 2003 to Mar.2012 in the Second Xiangya Hospital of Central South University,aged 4-14 years old(50 cases were male,46 cases were female),with a mean age of (8.55 ±2.71)years.The detailed history,physical examinations,conventional 12 lead electrocardiogram,chest x-ray,and echocardiography were all investigated,as well as the examination of myocardial enzyme,to eliminate the disorders of organic chest wall,heart,lung disease,and then HUTT inspection was given to them.Results HUTT positive rate was 31.25％ (30/96 cases),and no gender differences were found [20.00％ (10/50 cases) vs 43.48 ％ (20/46 cases),x2 =3.196,P ＞0.05].The positive cases included the basic head-up tilt table test in 2 cases(6.67％) and sublingual nitroglycerin head-up tilt test in 28 patients(93.33％).The hemodynamic changes in HUTT were found in 26 cases of vascular inhibited type(86.67％),heart inhibited type in 1 patient(3.33％) and the mixed type in 3 cases(10.00％).Conclusions Almost a third of children with unexplained sighs are related to the autonomic function disorder.HUTT may help to determine the causes of clinical unexplained sighs in children.