Relationship between hemodynamic type and syncopal symptoms in pediatric vasovagal syncope.

Vasovagal syncope (VVS) is a clinically common neurally mediated syncope. The relationship between different hemodynamic types of VVS and clinical syncopal symptoms has not been reported. The purpose of this research is to explore relationship between hemodynamic types and syncopal symptoms in pediatric VVS. Two thousand five hundred thirteen patients diagnosed with VVS at the age of 3-18 years, average age was 11.76 ± 2.83 years, including 1124 males and 1389 females, due to unexplained syncope and pre-syncope from single-center of January 2001 to December 2021 were retrospectively analyzed. Subjects were divided into two groups according to the presence or absence of syncopal symptoms: syncope group (1262 cases) and pre-syncope group (1251 cases). (1) Baseline characteristics: age, height, weight, systolic blood pressure (SBP), and diastolic blood pressure (DBP) increased in the syncope group compared with the pre-syncope group; the composition ratio of females was more than that of males in the syncope group; and the composition ratio of VVS-cardioinhibited (VVS-CI) and VVS-mixed (VVS-M) was more in the syncope group than that of the pre-syncope group (all P < 0.05). (2) Univariate analysis: age, height, weight, SBP, DBP, female, VVS-CI, and VVS-M were potential risk factors for the presence of syncopal symptoms (all P < 0.05). (3) Multivariate analysis: VVS-CI and VVS-M were independent risk factors for the presence of syncopal symptoms, with an increased probability of 203% and 175%, respectively, compared to VVS-vasoinhibited (VVS-VI) (all P < 0.01). CONCLUSION: The hemodynamic type of pediatric VVS is closely related to the syncopal symptoms. WHAT IS KNOWN: • There are varying probabilities of syncopal episodes in different hemodynamic types of VVS, and there is a lack of research to assess the comparative risk of syncope in children with different hemodynamic types of VVS. WHAT IS NEW: • The probability in presence of syncopal symptoms varies greatly between different hemodynamic types of VVS. • VVS-CI and VVS-M had a 203% and 175% increased risk in presence of syncopal symptoms compared with VVS-VI, respectively.

Relationship between syncopal symptoms and head-up tilt test modes.

OBJECTIVE: Head-up tilt test (HUTT) is an important tool in the diagnosis of pediatric vasovagal syncope. This research will explore the relationship between syncopal symptoms and HUTT modes in pediatric vasovagal syncope. METHODS: A retrospective analysis was performed on the clinical data of 2513 children aged 3-18 years, who were diagnosed with vasovagal syncope, from Jan. 2001 to Dec. 2021 due to unexplained syncope or pre-syncope. The average age was 11.76 ± 2.83 years, including 1124 males and 1389 females. The patients were divided into the basic head-up tilt test (BHUT) group (596 patients) and the sublingual nitroglycerine head-up tilt test (SNHUT) group (1917 patients) according to the mode of positive HUTT at the time of confirmed pediatric vasovagal syncope. RESULTS: (1) Baseline characteristics: Age, height, weight, heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and composition ratio of syncope at baseline status were higher in the BHUT group than in the SNHUT group (all P < 0.05). (2) Univariate analysis: Age, height, weight, HR, SBP, DBP, and syncope were potential risk factors for BHUT positive (all P < 0.05). (3) Multivariate analysis: syncope was an independent risk factor for BHUT positive, with a probability increase of 121% compared to pre-syncope (P<0.001). CONCLUSION: The probability of BHUT positivity was significantly higher than SNHUT in pediatric vasovagal syncope with previous syncopal episodes.

Clinical characteristics and hemodynamic responses to head-up tilt test in children and adolescents with unexplained sighing.

OBJECTIVE: Sighing is a common symptom in children and adolescents. In this study, we explored the clinical characteristics and hemodynamic responses to head-up tilt test (HUTT) in children and adolescents with unexplained sighing. METHODS: One hundred ninety-two children and adolescents complaining of unexplained sighing were enrolled as study group after excluding chest wall, lung, heart diseases, and psychogenic disorders. Sixty-nine healthy individuals were enrolled as control group. All the subjects underwent HUTT. RESULTS: Nitroglycerin-stimulated HUTT positive rate was higher in the study group than the control group (24.0% vs 10.1%, P = 0.014). In total, 32.3% of patients with sighing had positive responses to HUTT, which was higher than that of healthy individuals (32.3% vs 15.9%, P = 0.009). Among 62 cases with positive responses to HUTT in the study group, 48 cases were vasoinhibitory type vasovagal syncope (VVS), 5 cases were mixed type VVS, 3 cases were cardioinhibitory type VVS, 5 cases were postural tachycardia syndrome, and one case was orthostatic hypertension. Sighing patients with positive responses to HUTT had female dominance (54.8% vs39.2%, P = 0.045), older mean age (9.6 ± 2.8 vs 8.1 ± 2.7 years old, P = 0.001), higher basic systolic blood pressure (104.8 ± 10.4 vs 101.1 ± 9.9 mmHg, P = 0.019), and higher diastolic blood pressure (66.0 ± 7.5 vs 62.9 ± 9.2 mmHg, P = 0.021) compared with those of negative responses. CONCLUSIONS : Nearly one-third of children and adolescents with unexplained sighing had positive responses to HUTT, demonstrating that sighing was related to dysfunction of the autonomic nervous system. Elder female patients with higher systolic and diastolic blood pressure were more likely to have positive responses to HUTT.

Heart Rate and Heart Rate Difference Predicted the Efficacy of Metoprolol on Postural Tachycardia Syndrome in Children and Adolescents.

OBJECTIVE: To evaluate the ability of heart rate (HR) and HR difference during head-up tilt test (HUTT) and to predict clinical improvement related to metoprolol treatment in children and adolescents with postural tachycardia syndrome (POTS). STUDY DESIGN: This was a retrospective cohort study. A total of 53 subjects (27 male, aged 6-12 years old, mean age 11.79 ± 1.50 years old) with POTS treated with metoprolol were involved from July 2012 to September 2019. In total, 52 subjects who underwent health examination during the same period were matched as the control group. Subjects in both groups underwent HUTT. The HR distance between 5 minutes and 0 minutes (HR difference 5) and between 10 minutes and 0 minutes (HR difference 10) during HUTT was calculated. RESULTS: The POTS group was significantly greater than the control group in HR 5, HR 10, HR difference 5, and HR difference 10 (P < .01). There was no statistical difference in HR 0 between the 2 groups (P > .05). In total, 53 subjects with POTS were followed up for 96.0 (IQR, 40.5, 134.5) days during treatment with metoprolol. HUTT results demonstrated that 58.49% of subjects with POTS had a response and symptom scores were reduced after intervention. HR and HR difference were useful in predicting the efficacy of metoprolol on POTS. When HR 5, HR 10, HR difference 5, and HR difference 10, respectively, were ≥110, 112, 34, and 37 beats/min, the sensitivity and specificity were 82.50% and 69.23%, 84.62% and 69.70%, 85.29% and 89.47%, and 97.56% and 64.86%, respectively. CONCLUSIONS: HR and HR difference are helpful to predict the efficacy of metoprolol on POTS in children and adolescents.

Clinical values of creatine kinase and its isoenzymes in children and adolescents with vasovagal syncope.

BACKGROUND AND AIM: Vasovagal syncope (VVS) in children and adolescents is a common disorder. There may be an internal relationship between creatine kinase (CK) and its isoenzymes (CKMB) and syncope. The aim of this study was to evaluate the changes of CK and CKMB in children and adolescents with VVS. METHODS AND RESULTS: The VVS group included 218 patients (93 male and 125 female). The control group included 129 healthy children (78 male and 51 female). Serum CK and CKMB levels were estimated. We founded ①Serum CK and CK-MB levels decreased in VVS group than that in control group (P < 0.05). ②The CK levels of female were significantly lower than those of male in VVS group (P < 0.05). ③Serum level of CK-MB were in negative correlation with age, height, weight, BMI whereas in positively correlation with HR. ④CK was effected by CK-MB (ß = 0.147, P = 0.037) while CK-MB was independently influenced by age (ß = -0.203, P = 0.002) and DBP (ß = 0.171, P = 0.011). ⑤Both CK and CK-MB significantly influenced on VVS occurrence after adjusting for the effects of gender, age, height, weight, BMI and HR. CONCLUSION: The serum CK and CKMB levels decrease in children and adolescents with VVS. CK and CK-MB are the independent protective factors with VVS.

Diagnostic and prognostic value of T-wave amplitude difference between supine and orthostatic electrocardiogram in children and adolescents with postural orthostatic tachycardia syndrome.

OBJECTIVE: To investigate the diagnostic and prognostic value of T-wave amplitude difference between supine and orthostatic electrocardiogram (ECG) in children and adolescents with postural orthostatic tachycardia syndrome (POTS). METHODS: A total of 100 children and adolescents (POTS group, 50 males and 50 females, aged at 11.0 ± 2.4 years) diagnosed as POTS were enrolled from August 2013 to July 2016. Seventy-one children were matched as the control group according to age and sex. All cases completed the supine and orthostatic ECG. RESULTS: (a) Compared with the control group, the T-wave amplitude difference in leads I, II, aVL, V4 , V5, and V6 and the heart rate (HR) difference increased in POTS group. (b) Logistic regression analysis: The T-wave amplitude difference in leads V4 , V5 , and V6 and HR difference have statistical significance for POTS diagnosis. (c) Diagnostic test evaluation: When HR difference was ≥ 15 times/min, T-wave amplitude difference in lead V5 was ≥0.15 mV, T-wave amplitude difference in leads V4 and V6 were ≥0.10 mV, and the sensitivity and specificity of POTS diagnosis were 35.0% and 88.7%. (d) Follow-up: There was no significant difference in HR difference and T-wave amplitude difference in the nonresponse groups. In the response group, the T-wave amplitude difference in lead V4 was reduced than the initial value. CONCLUSIONS: The HR difference and T-wave amplitude difference in leads V4, V5, and V6 between supine and orthostatic ECG are of help in assisting the diagnosis of POTS but no obviously significance on prognosis estimation of it.

The clinical characteristics of situational syncope in children and adults undergoing head-up tilt testing.

OBJECTIVE: Situational syncope is a subtype of neurally mediated syncope and associated with specific circumstances. This paper is to assess the clinical characteristics and underlying causes of situational syncope. METHODS: This is a retrospective study of patients who underwent head-up tilt testing (HUTT). Medical records including age at HUTT, gender, number of syncopal episodes, family history of syncope, triggers before the syncopal episode, position during the syncopal episode and the responses to HUTT were reviewed. RESULTS: Among 3140 patients, 354 patients (mean age 28.3 ± 16.6 years old, with 184 males and 170 females) were diagnosed with situational syncope. The causes of situational syncope included micturition (50.85%), defecation (15.82%), bathing (10.45%), swallowing (6.50%), cough (4.80%), post-dinner (3.95%), singing (3.11%), teeth brushing (2.26%), and hair grooming (2.26%). Patients with syncope triggered by micturition, cough, post-dinner were more likely to be men, while those caused by bathing, swallowing, singing, teeth brushing and hair grooming were more likely to be women. 34.75% of patients with situational syncope were between the ages of 10-19 years old, and 20.34% were between the ages of 40-49 years old. 74.01% of situational syncopal events occurred in an upright position. 47.74% of patients had positive responses to HUTT. CONCLUSIONS: These findings show that micturition was the most common cause of situational syncope in both children and adults. There were significant gender and age differences among situational syncope triggered by different causes. Most of situational syncope occurred in the upright position and nearly half of the patients had positive responses to HUTT.

[Efficiency of heart rate and heart rate difference at different time points during head-up tilt test in the diagnosis of postural tachycardia syndrome in children and adolescents].

OBJECTIVE: To study the efficiency of heart rate (HR) and heart rate difference (HRD) at different time points during head-up tilt test (HUTT) in the diagnosis of postural tachycardia syndrome (POTS) in children and adolescents. METHODS: A total of 217 children and adolescents, aged 6-16 years, who were diagnosed with POTS were enrolled as the POTS group, and 73 healthy children and adolescents, matched for sex and age, were enrolled as the control group. The POTS group was further divided into ≤12 years old group with 127 children/adolescents and >12 years old group with 90 children/adolescents. The two groups were compared in terms of HR at baseline and at 5 and 10 minutes of HUTT (HR0, HR5, and HR10 respectively), difference between HR5/HR10 and HR0 (HRD5 and HRD10 respectively). The efficiency of HR5, HR10, HRD5 and HRD10 in the diagnosis of POTS was assessed. RESULTS: Compared with the control group, the POTS group had significant increases in HR5, HR10, HRD5, and HRD10 (P<0.05). The coincidence rate of HR or HRD for the diagnosis of POTS in males was higher than that in females at 5 minutes of HUTT (P<0.05), while the coincidence rate of HR or HRD for the diagnosis of POTS in males was lower than that in females at 10 minutes of HUTT (P<0.05). The coincidence rate of HR for the diagnosis of POTS was higher in the >12 years old subgroup (P<0.05), while the coincidence rate of HRD for the diagnosis of POTS was higher in the ≤12 years old subgroup (P<0.05). The combination of HR5, HR10, HRD5, and HRD10 for the diagnosis of POTS had a greater area under the curve (0.974; 95%CI: 0.949-0.989) than HR5, HR10, HRD5, or HRD10 alone, with a sensitivity of 87.80% and a specificity of 95.83%. The diagnostic efficacy of HRD for POTS was higher than that of HR (P<0.05). CONCLUSIONS: HR and HRD at different time points during HUTT have a good value in the diagnosis of POTS in children and adolescents, and the accuracy of diagnosis varies with age and gender.

[Association of T-wave amplitude on electrocardiogram with left ventricular ejection fraction in children with dilated cardiomyopathy].

OBJECTIVE: To study the association of T-wave amplitude on electrocardiogram (ECG) with left ventricular ejection fraction (LVEF) in children with dilated cardiomyopathy. METHODS: A retrospective analysis was performed for the clinical data of 44 children who were diagnosed with dilated cardiomyopathy from May 2009 to June 2018. According to LVEF, they were divided into two groups: LVEF ≥50% group (n=26) and LVEF <50% group (n=18). After treatment, 25 children were followed up for 3-42 months (mean 14±9 months). The Guangdong Zhongshan SR-1000A ECG Automatic Analyzer was used to obtain the 12-lead body surface ECG results in the supine position. T-wave amplitude on ECG was evaluated by software and manual measurement. RESULTS: Compared with the LVEF ≥50% group, the LVEF <50% group had a significant reduction in the T-wave amplitude in leads II, V4, V5 and V6 (P<0.05). The increased-LVEF group (an increase in LVEF > 5% after treatment) had a significant increase in the T-wave amplitude in leads aVR, V5, and V6 after treatment (P<0.05), while the unchanged-LVEF group (an increase in LVEF ≤ 5% after treatment) had a significant reduction in the T-wave amplitude in lead aVR after treatment (P<0.05). The receiver operating characteristic curve analysis showed that the T-wave amplitude in leads II, V4, V5 and V6 had a certain value in predicting LVEF <50% in children with dilated cardiomyopathy (P<0.05). A combination of T-wave amplitude of ≤0.20 mV in lead II, ≤0.40 mV in lead V4, and ≤0.30 mV in leads V5 and V6 had a sensitivity of 88.2% and specificity of 76.0% in the predication of LVEF <50% in children with dilated cardiomyopathy. CONCLUSIONS: T-wave amplitude on ECG can be used as the indexes for the evaluation of the left ventricular systolic function in children with dilated cardiomyopathy.

[T wave and ST segment amplitude changes in the supine and standing electrocardiograms of children with orthostatic hypertension and their clinical significance].

OBJECTIVE: To examine the changes in T wave and ST segment amplitude in the supine and standing electrocardiograms (ECG) of children with orthostatic hypertension (OHT) and to determine their clinical significance. METHODS: A total of 49 children with OHT were included in the OHT group. Forty-three age- and sex-matched healthy children were included in the control group. Heart rate and T wave and ST segment amplitude were measured in both groups. T wave amplitude and ST segment amplitude in supine ECG were compared with those in standing ECG within each group. The differences in supine vs standing T wave amplitude and ST segment amplitude were compared between the OHT and control groups. RESULTS: In the control group, T wave amplitude in leads aVR, V1, and V4-V6 were significantly lower in standing ECG than in supine ECG (P<0.05); ST segment amplitude in leads V4 and V5 were significantly higher in standing ECG than in supine ECG (P<0.05). In the OHT group, T wave amplitude in leads II, aVR, aVF, and V4-V6 were significantly lower in standing ECG than in supine ECG (P<0.05); ST segment amplitude in lead II was significantly higher in standing ECG than in supine ECG (P<0.05). The differences in T wave amplitude in lead II and V6 between supine and standing ECG were significantly higher in the OHT group than in the control group (P<0.05). Difference in T wave amplitude in lead V6 between supine and standing ECG was a significant diagnostic marker for OHT (P<0.05). This marker had 72.10% sensitivity and 57.10% specificity for the diagnosis of OHT at the optimal cut-off value of 0.105 mV. CONCLUSIONS: Difference in T wave amplitude in lead V6 between supine and standing ECG has certain diagnostic value for OHT.

[Comparison of curative effect and serum electrolytes between different oral rehydration salts in treatment of neurally mediated syncope children].

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 (χ2=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 (χ2=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].

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.

Calgary score and modified Calgary score in the differential diagnosis between neurally mediated syncope and epilepsy in children.

To evaluate the value of Calgary score and modified Calgary score in differential diagnosis between neurally mediated syncope and epilepsy in children. 201 children experienced one or more episodes of loss of consciousness and diagnosed as neurally mediated syncope or epilepsy were enrolled. Calgary score, modified Calgary score and receiver-operating characteristic curve were used to explore the predictive value in differential diagnosis. There were significant differences in median Calgary score between syncope [-4.00 (-6, 1)] and epilepsy [2 (-3, 5)] (z = -11.63, P < 0.01). When Calgary score ≥1, the sensitivity and specificity of differential diagnosis between syncope and epilepsy were 91.46 and 95.80 %, suggesting a diagnosis of epilepsy. There were significant differences in median modified Calgary score between syncope [-4.00 (-6, 1)] and epilepsy [3 (-3, 6)] (z = -11.71, P < 0.01). When modified Calgary score ≥1, the sensitivity and specificity were 92.68 and 96.64 %, suggesting a diagnosis of epilepsy. The sensitivity and specificity of modified Calgary score and Calgary score did not show significant differences (P > 0.05). Calgary score and modified Calgary score could be used to differential diagnosis between syncope and epilepsy in children.

[Incidence of long (short) PR interval in electrocardiogram among healthy people in Changsha and its clinical significance].

OBJECTIVE: To analyze the incidence of long (short) PR interval in electrocardiogram among healthy people in Changsha and the clinical significance.
 METHODS: Twelve-lead body surface electrocardiogram was taken to measure the heart rates and PR intervals from 4 025 healthy individuals (age range from 6 min after birth to 83 years old) who performed physical examination from Jan, 1993 to Dec, 2012 in the Second Xiangya Hospital, Central South University. Statistics were analyzed by SPSS 16.0.
 RESULTS: The total incidence of short PR interval was 19.65% (791/4 025). The age group from birth to 13 years old had a higher incidence than the other age groups (χ2=432, P<0.01). The age groups from 1 month after birth and from 1 month to younger than 1 year-old displayed the highest incidences (43.29% and 44.34%, respectively). The lowest incidences were obtained from the 14-17 year-old, 40-49 year-old and 50-59 year-old groups (0.20%, 0.41%, and 0.33%, respectively). The total incidence of long PR intervals was 3.58% (144/4 025). The 1 year-old group had the highest incidence (6.74%), which decreased with the increase of age. The lowest incidence of long PR intervals occurred in the age group from 14-17 years old, which gradually increased after 50 years old. There were no significant differences in long (short) PR intervals between the gender (P>0.05).
 CONCLUSION: The incidence of long (short) PR intervals varies in different age groups of healthy people. The incidences of long (short) PR intervals in children before 10 years old are higher than those in adults, especially the short PR intervals, as a result of the heart rate affected by childhood autonomic nervous function and the change in atrial volume with age. Adults have long (short) PR interval should be regularly followed-up to prevent cardiovascular events.

[Changes in P-wave, T-wave, and ST segment amplitude in 12 lead electrocardiogram in children with breath holding spell].

OBJECTIVE: To explore the change of the amplitude of P wave, T wave and ST segment of 12 lead electrocardiogram (ECG) in children with breath holding spell.
 METHODS: A total of 29 children (24 males and 5 females) with breath holding spell in Second Xiangya Hospital, Central South University were enrolled for this study from October, 2009 to September, 2015. Their ages ranged from 3 months to 6 years, with an average of 1.82±1.27 years old. The control group consisted of 30 age-matched and gender-matched healthy children. All subjects were underwent electrocardiography by the SR-1000A comprehensive automatic electrocardiograph analyzer, and the changes of the ECG parameters were compared between the two groups.
 RESULTS: Compared with the control group, the amplitude of P-wave of V5 lead was decreased [(44.10±23.98) vs (58.30±21.19) µV, P<0.05], the amplitude of T-wave of V6 lead was increased [(423.80±122.6) vs (350.00±105.73) µV, P<0.05], the amplitude of ST segment of II lead was increased [(84.80±39.97) vs (57.30±38.77) µV, P<0.05], the amplitude of ST segment of aVR lead was increased [(-77.60±37.41) vs (-51.00±33.46) µV, P<0.05], the amplitude of ST segment of aVL lead was increased [(35.20±28.24) vs (17.70±33.90) µV, P<0.05], the amplitude of ST segment of V5 lead was increased [(111.00±59.36) vs (69.00±36.33) µV, P<0.05], the amplitude of ST segment of V6 lead was increased [(79.30±45.51) vs (51.30±33.19) µV, P<0.05]. 
 CONCLUSION: The children with breath holding spell have autonomic nerve dysfunction. The amplitude of ST segment changes is sensitive.

[Differences of age and gender in orthostatichypertension-a single-center study].

OBJECTIVE: To explore the differences of Chinese people's age and gender in orthostatic hypertension (OHT) by a single-center experience study.
 METHODS: A total of 2 994 patients with unexplained syncope and dizziness, who were outpatients or had been hospitalized in Second Xiangya Hospital, Central South University from January 2000 to August 2012, were chosen and subjected to the head-up tilt table test (HUTT). Their ages ranged from 2.00 to 78.00 years old, with an average at 19.07±14.78 years old. There were 1 406 and 1 588 cases for male and female, respectively. A total of 745 patients were OHT, who were divided into a adult group (≥18 years old, 247/904 cases) and a children group (<18 years old, 498/2 090 cases). The difference of the occurrence rate, classification, and 3 min quantity of blood pressure were analyzed.
 RESULTS: 1) The incidence of OHT in HUTT was 24.88% (745/2 994 cases). There was no statistical difference between the males and the females(25.75% vs 24.12%, χ2=1.058, P>0.05), but it was higher in the adult group compared with that in the children group (27.05% vs 23.83%, χ2=4.125, P=0.042). There were 52 cases (6.98%) of high systolic and high diastolic blood pressure (sOHT merge dOHT), 16 cases (2.15%) of simple high systolic blood pressure OHT (sOHT), and 677 cases (90.87%) of simple high diastolic blood pressure OHT (dOHT) in the 745 patients with OHT. The incidence of dOHT and sOHT merge sOHT in the adults group were significantly higher than those in the children group (1.11% vs 0.29%, χ2=7.965, P<0.01; 2.88% vs 1.24%, χ2=9.849, P<0.01, respectively); there was no statistical difference in simple dOHT between males and females (23.56% vs 22.20%, χ2=0.668, P>0.05); there was also no statistical difference in sOHT plus dOHT and dOHT between males and females (sOHT merge dOHT: 1.71% vs 1.76%, χ2=0.014, P>0.05; dOHT: 23.68% vs 21.66%, χ2=1.742, P>0.05; 1.71% vs 1.76%, χ2=0.014, P>0.05, respectively); but the dOHT was significantly higher in the males than that in the females in the children group (24.53% vs 19.74%, χ2=6.933, P>0.05). 2) There was no difference in the increment of systolic blood pressure in sOHT plus dOHT [(25.62±4.96) mmHg vs (23.54±5.83) mmHg, t=1.385, P>0.05] and the increment of diastolic blood pressure in dOHT [(13.46±3.49) mmHg vs (13.23±3.22) mmHg, t=0.840, P>0.05] between the adults group and the children group. There was no difference in the increment of systolic blood pressure in sOHT [(25.44±4.96) mmHg vs (23.68±5.35) mmHg, t=1.411, P>0.05] and the increment of diastolic blood pressure in dOHT [(14.09±4.28) mmHg vs (13.05±3.82) mmHg, t=1.887, P>0.05] between the adults group and the children group.
 CONCLUSION: The incidence of OHT is higher in the adults group than that in the children group. There is no difference in systolic and diastolic blood pressure increment within 3 minutes during HUTT between the adults and children.

Oral rehydration salts: an effective choice for the treatment of children with vasovagal syncope.

To explore whether oral rehydration salts (ORS) is effective in the treatment of children with vasovagal syncope (VVS). One hundred and sixty-six consecutive patients with recurrent syncope and positive head-up tilt testing (HUTT) were recruited, randomly divided to conventional therapy (health education and tilt training) plus ORS (with 500 ml of water) group (Group I, 87 patients) and conventional therapy group (Group II, 79 patients). Therapeutic effect was evaluated by changes of syncopal episode and reperformed HUTT response. At the end of 6-month follow-up, syncopal episode did not reoccur in 49 (56.3 %) patients, decreased in 34 (39.1 %) patients, and had no obvious change or increased in four (4.6 %) patients in Group I, and the results were 31 (39.2 %), 37 (46.8 %), and 11 (14 %) in Group II, respectively. The difference was significant (χ (2) = 7.074, P < 0.05). When HUTT was reperformed, 57 (65.5 %) and 28 (35.4 %) patients had negative response and 30 (34.5 %) and 51 (64.6 %) patients had positive response, respectively, in Group I and Group II. The difference was also significant (χ (2) = 13.808, P < 0.01). In Group I, the two aspects had no difference between vasodepressor type and mixed type; however, syncopal episode had a significant difference between children aged ≤12 and >12 years (χ (2) = 6.371, P < 0.05); there was no difference in reperformed HUTT response. ORS with 500 ml of water is an effective therapy for VVS. It can be recommended as one of non- pharmacological treatment measures in children with VVS.

Genetic polymorphisms in alcohol dehydrogenase, aldehyde dehydrogenase and alcoholic chronic pancreatitis susceptibility: a meta-analysis.

PURPOSE: This study was aimed to determine the relationship of alcohol-metabolizing enzymes ADH2, ADH3, and ALDH2 polymorphisms with the susceptibility to alcoholic chronic pancreatitis (ACP). METHODS: Meta-analyses that evaluated the association of ADH2, ADH3, and ALDH2 variations with ACP were performed. RESULTS: Eight case-control studies were selected for analysis. The overall data revealed a significant association of ADH2 polymorphism (OR=1.56, 95% CI=1.42-1.72, P=0.000 for dominant model; OR=1.63, 95% CI=1.55-1.71, P=0.000 for homozygote comparison model; OR=1.11, 95% CI=1.01-1.22, P=0.030 for allelic contrast model), ADH3 polymorphism (OR=0.95, 95% CI=0.86-1.06, P=0.389 for dominant; OR=0.64, 95% CI=0.44-0.93, P=0.020 for homozygote comparison; and OR=0.87, 95% CI=0.77-0.99, P=0.039 for allelic contrast model) and ALDH2 polymorphism (OR=0.57, 95% CI=0.40-0.81, P=0.002 for dominant; OR=0.50, 95% CI=0.23-1.08, P=0.079 for homozygote comparison; and OR=0.58, 95% CI=0.41-0.84, P=0.003 for allelic contrast model) with ACP risk. The subgroup analyses suggested that the variant ADH2*2/*2+*1/*2, ADH2*2/*2 genotype and ADH2*2 allele significantly increased ACP risk among Asian individuals; the variant ADH3*2/*2 genotype and ADH3*2 allele significantly decreased ACP risk among non-Asian individuals; and the variant ALDH2*2/*2+*1/*2 genotype and ALDH2*2 allele significantly decreased ACP risk among Asians. CONCLUSIONS: ADH2, ADH3 and ALDH2 polymorphisms may be susceptibility facts of ACP, and it may be ethnic and race-dependent.

[Time-dependent heart rate variability in the head-up tilt test in children with postural orthostatic tachycardia syndrome].

OBJECTIVE: To study the time-dependent heart rate (HR) variability in the head-up tilt test (HUTT) in children with postural orthostatic tachycardia syndrome (POTS) and to explore the HR diagnostic criteria for POTS in children. METHODS: A retrospective analysis was performed on the clinical data of 105 children diagnosed with POTS with HR≥120 beats per minute (bpm) within the first 10 minutes of HUTT between January 2007 and December 2014. Their HR variability within the first 10 minutes of HUTT was analyzed. RESULTS: The HR of children with POTS increased gradually from the supine position to a 60° head-up tilt position, and the increase in HR was 24±12 bpm at the beginning of HUTT, 30±14 bpm at 3 minutes of HUTT, 32±13 bpm at 5 minutes of HUTT, and 38±12 bpm at 10 minutes of HUTT. The average maximal HR increase within the first 10 minutes of HUTT was 43±10 bpm. CONCLUSIONS: In children with POTS, the HR variability gradually increases with time, and therefore, it is suggested that HR increase ≥40 bpm is more suitable for diagnosis of POTS in children.

[Evaluation of psychological fear in children undergoing head-up tilt test].

OBJECTIVE: To investigate the effects of different tilt angles of head-up tilt test (HUTT) and different responses to HUTT on the psychological fear in children undergoing the test. METHODS: HUTT was performed on children with unexplained syncope or pre-syncope (107 cases: 52 males and 55 females), aged 5.5-17.8 years (mean 12.0±2.8 years). All subjects were randomly assigned to undergo HUTT at an angle of 60°, 70° or 80°; the negative cases underwent sublingual nitroglycerin-provocation HUTT at the same tilt angle. The Wong-Baker Faces Pain Rating Scale was used for self-assessment of psychological fear in subjects during HUTT at the end point of the test. RESULTS: The positive rate, hemodynamic changes and distribution of response types showed no significant differences between children at tilt angles of 60°, 70° and 80° (P>0.05). The greater the tilt angle, the higher the degree of psychological fear in children undergoing the test, but there were no significant differences between them (P>0.05). The degree of psychological fear in children who showed a positive response to HUTT (n=76) was significantly higher than that in children who showed a negative response (n=31) (P<0.01). CONCLUSIONS: HUTT can cause psychological fear in children undergoing the test, and the degree of psychological fear increases in children tested at tilt angles from 60° to 80°, but the differences have no statistical significance. A positive response to HUTT can significantly increase the psychological fear in children.