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, V, and V-V were significantly lower in standing ECG than in supine ECG (P<0.05); ST segment amplitude in leads V and V 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 V-V 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 V 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 V between supine and standing ECG has certain diagnostic value for OHT.
Child ; Electrocardiography ; Heart Rate ; Humans ; Hypertension ; Sensitivity and Specificity ; Standing Position

OBJECTIVETo 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.

METHODSA 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.

RESULTSThe 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.

CONCLUSIONSIn 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.

Adolescent ; Child ; Child, Preschool ; Female ; Heart Rate ; physiology ; Humans ; Male ; Postural Orthostatic Tachycardia Syndrome ; physiopathology ; Retrospective Studies ; Tilt-Table Test

OBJECTIVETo assess the value of multiplex PCR-denaturing high-performance liquid chromatography (PCR-DHPLC) method for screening large duplications or deletions in patients with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA).

METHODSDNA was extracted from peripheral venous blood samples from 35 DMD and 6 SMA patients. Large duplications or deletions were screened with multiplex PCR coupled with DHPLC method. The results were validated with testing of positive and negative controls.

RESULTSKnown duplications or deletions in all controls were reliably detected with multiple PCR coupled with DHPLC. Large duplications or deletions were found in 71.4% of 35 DMD patients, which included 5 large duplications and 20 large deletions. For SMA patients, deletions of SMN1 exon 7 were detected in 16 samples.

CONCLUSIONMultiplex PCR coupled with DHPLC method is an effective and reliable method for detecting large genomic duplications or deletions in patients with DMD or SMA.

Chromatography, High Pressure Liquid ; Dystrophin ; genetics ; Gene Deletion ; Gene Duplication ; Humans ; Multiplex Polymerase Chain Reaction ; Muscular Atrophy, Spinal ; diagnosis ; genetics ; Muscular Dystrophy, Duchenne ; diagnosis ; genetics ; Survival of Motor Neuron 1 Protein ; genetics

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.
Adolescent ; Blood Pressure ; Child ; Female ; Heart Rate ; Humans ; Male ; Postural Orthostatic Tachycardia Syndrome ; Tilt-Table Test

OBJECTIVETo 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.

METHODSHUTT 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.

RESULTSThe 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).

CONCLUSIONSHUTT 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.

Adolescent ; Child ; Child, Preschool ; Fear ; Female ; Humans ; Male ; Tilt-Table Test ; psychology

Objective: To investigate the predictive value of blood cell parameters in children with vasovagal syncope (VVS). Methods: In this case-control study, the VVS group included 111 patients with unexplained syncope or prodromata who were diagnosed with VVS by head-up tilt test in the Second Xiangya Hospital, Central South University from January 2018 to October 2020, and 111 healthy children were enrolled as control. The differences in blood cell parameters between the 2 groups were compared by t test and Mann-Whitney U test. Multivariate binary Logistic regression was used to analyze the independent correlation factors of VVS, and receiver operating characteristic (ROC) curve to explore the predictive value of blood cell parameters for diagnosing VVS. Results: Sex composition ratios were consistent in the 2 groups (51 males vs. 60 females), while the age of the VVS group was higher than that of the control group (11.0 (8.0, 12.5) vs. 8.0 (7.0, 11.0) years, Z=4.39, P<0.001). Compared with the control group, VVS group had lower level of white blood cell (WBC) (6.0 (5.3, 7.1)×10⁹ vs. 8.6 (6.7, 10.1)×10⁹/L, Z=-7.96, P<0.001), lymphocyte (LY) (2.3 (1.9, 2.7)×10⁹ vs. 4.0 (2.8, 6.3)×10⁹/L, Z=-8.49, P<0.001), lymphocyte ratio (0.39 (0.33, 0.44) vs. 0.52 (0.37, 0.69), Z=-5.59, P<0.001), monocyte (0.3 (0.3, 0.4)×10⁹ vs. 0.4 (0.3, 0.6)×10⁹/L, Z=-6.19, P<0.001), eosinophil (0.1 (0.1, 0.2)×10⁹ vs. 0.2 (0.2, 0.4)×10⁹/L, Z=-5.75, P<0.001), mean corpuscular-hemoglobin concentration (MCHC) ((328±12) vs. (333±11) g/L, t=-3.27, P<0.001) and blood platelet (263 (235, 313)×10⁹ vs. 341 (295, 409)×10⁹/L, Z=-2.69, P<0.001), but higher neutrophil ratio (0.53 (0.48, 0.58) vs. 0.37 (0.22, 0.54), Z=5.86, P<0.001), hematocrit (0.39±0.04 vs. 0.37±0.04, t=2.75, P=0.006), mean corpuscular volume (MCV) (85 (82, 88) vs. 81 (78, 84) fl, Z=5.56, P<0.001), mean corpuscular hemoglobin (28 (27, 29) vs. 27 (26, 28) pg, Z=3.39, P=0.001), red cell distribution width (39 (37, 41) vs. 37 (36, 40) fl, Z=4.02, P<0.001) and mean platelet volume (11 (10, 11) vs. 10 (9, 11) fl, Z=2.81, P=0.005) levels. After adjusting for confounding factors such as sex and age, LY (OR=0.42, 95%CI 0.29-0.62, P<0.001), WBC (OR=0.75, 95%CI 0.59-0.95, P=0.015), MCHC (OR=0.94, 95%CI 0.91-0.97, P<0.001) were independent negative correlation factors of VVS, while MCV (OR=1.08, 95%CI 1.01-1.15, P=0.021) was independent positive correlation factor. ROC curve showed that the combination of LY, WBC, MCV and MCHC had acceptable predictive value for the diagnosis of VVS, with area under curve of 0.88, sensitivity of 0.80, specificity of 0.83, and Youden index of 0.63. Conclusions: Compared with healthy children, the blood cell parameters usually change in those with VVS. Combination of LY, WBC, MCHC and MCV can facilitate the diagnosis of VVS in children with unexplained syncope or prodromata.
Case-Control Studies ; Child ; Female ; Humans ; Lymphocytes ; Male ; Syncope ; Syncope, Vasovagal/diagnosis* ; Tilt-Table Test