Effect of Levocarnitine on the Therapeutic Efficacy of Conventional Therapy in Children with Dilated Cardiomyopathy: Results of a Randomized Trial in 29 Children.

BACKGROUND: The effect of levocarnitine supplementation has not been evaluated in children with dilated cardiomyopathy (DCM). OBJECTIVE: The aim of this study was to explore the effect of oral levocarnitine supplementation in pediatric patients with DCM. METHODS: Twenty-nine children with DCM (17 male, 12 female, aged 1 month to 13 years) were divided into two groups according to a simple randomization: control group (n = 10) and experimental group (n = 19). All children were given oral hydrochlorothiazide, enalapril, and spironolactone; additionally, patients with cardiac function of NYHA grade IV were given oral digoxin, and patients with intractable heart failure were given intravenous dopamine and dobutamine. When cardiac function was restored to NYHA grade II-III, patients were given oral metoprolol. Patients in the experimental group received add-on treatment with oral levocarnitine solution (50-100 mg/kg/day). Patients were followed up at 1, 3, 6 and 12 months. Left ventricular ejection fraction (EF), short axis shortening (FS), and left atrium (LA) and left ventricle (LV) diameters were measured at different times during the follow-up. RESULTS: The children with DCM were followed up for 1 year. Cardiac function was significantly improved in the experimental group compared with the control group. Specifically, the EF and FS were increased (p < 0.05), the LA and LV diameters were reduced (p < 0.05), and the EF was increased more significantly in the experimental group than in the control group (p < 0.05). CONCLUSIONS: Oral levocarnitine solution appeared to enhance the therapeutic efficacy of conventional therapy in children with DCM.

The changes of electrolytes in serum and urine in children with neurally mediated syncope cured by oral rehydration salts.

OBJECTIVE: To detect the changes of electrolytes in serum and urine in children with nerve mediated syncope (NMS) cured by oral rehydration salts (ORS). METHOD: From May 2014 to April 2015, 135 patients with symptoms like unexplained syncope and presyncope were administrated in our hospital, including 60 boys and 75 girls, aged between 4 and 16 (10.2±2.7) years. After head-up tilt test (HUTT), their electrolytes in serum and urine were examined. Those who were positive to the HUTT received ORS and health education, while others were only treated by health education. With the period of subsequent visit arranging 21-154 (42.6±27.7) days, the improvement of their clinical manifestation were inquired and electrolytes in serum and urine were re-tested. RESULT: (1) The total effective percentage of ORS treatment was 63.0%, and the negative conversion rate of HUTT was 48.2%. (2) In the first time of visit to hospital, there was no statistical significance between the HUTT-positive and the HUTT- negative in serum electrolytes, 24-h urine electrolytes and 24-h urine volume (P>0.05). (3) In the return visit to hospital, the serum calcium and serum phosphorus in the HUTT-positive were higher than those in the HUTT-negative (P<0.05). (4) With the intake of ORS, 24-h urine sodium, 24-h urine chlorine and 24-h urine volume were improved than pre-treatment (P<0.05 or 0.01). CONCLUSION: ORS was an effective treatment to the NMS children, with 24-h urine volume and urine chloride increasing.

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.

The ventricular late potentials in children with vasodepressor response of vasovagal syncope.

OBJECTIVES: To discuss ventricular late potentials (VLPs) in children with vasodepressor response of vasovagal syncope (VVS-V). METHODS: 184 children diagnosed as VVS-V by head-up tilt test (HUTT) were enrolled as VVS-V group, 105 age and gender matched healthy individuals without syncope were used as control group, then signal-averaged electrocardiogram was measured. RESULTS: HR was decreased [(83.98±12.27) vs (87.28±13.75)bpm, P<0.05] in VVS-V group compared with control group. The prevalence of positive VLPs was not significantly different between the two groups. However the absolute values of TQRS [(84.89±12.05) vs (81.21±8.23)ms, P<0.01], RMS40 [(28.73±7.23) vs (26.89±7.36)µV, P<0.05] and LAS40 [(62.43±19.17) vs (56.79±1.83)ms, P<0.05] were significantly prolonged in VVS-V group compared with control group, and more patients in VVS-V group had abnormal prolonged LAS40 (94.57% vs 83.80%, P<0.01). CONCLUSIONS: The prevalence of positive VLPs was not significantly different, TQRS, RMS40, LAS40 were longer in children with VVS-V in comparison with healthy individuals, and the abnormal LAS40 occurred in a higher proportion of VVS-V group.

[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.

The circadian rhythm of syncopal episodes in patients with neurally mediated syncope.

OBJECTIVE: To explore the circadian rhythm of neurally mediated syncope (NMS). METHODS: 411 patients with NMS (165 males and 246 females aged from 3 to 68years) were included in the study. All subjects underwent head-up tilt test (HUTT) and were carefully asked about the number of syncopal attacks and the periods (morning 06:00am-12:00am, afternoon 12:00am-18:00pm, evening 18:00pm-24:00pm, night 00:00am-06:00am) in which episodes occurred in. RESULTS: (1) Syncopal attacks of all patients tended to occur in the morning (P=0.010); there was a statistical difference in the frequency of episodes in four periods through the day in HUTT positive patients (P=0.001), but there was no significant change of episodes within a day in HUTT negative group; and there was no statistical difference in circadian syncope distribution between HUTT negative and HUTT positive group or among patients with different HUTT responses (the orthostatic hypotension (OH) and orthostatic hypertension (OHT) patients were excluded). (2) The syncopal attacks of morning hours occurred more in males than females, but the episodes in the evening occurred more in females than males (P=0.034). (3) The younger the patients were, the chance of syncopal attacks in the morning increased; the older the patients were, they may have more episodes at night (P<0.001). CONCLUSIONS: A distinct circadian variation in the frequency of syncopal episodes exists, with a peak in the morning, and there were statistical differences in circadian rhythm of syncopal episodes regarding gender and age.

Transient aphasia: a rare complication of head-up tilt test.

Head-up tilt test (HUT) is widely used as a diagnostic tool. It reproduces vasovagal attacks in many susceptible patients. Although it is known to be safe and well tolerated, it is a procedure with potential neurologic complications. We observed that it could cause transient aphasia in some patients. To explore clinical characteristics and possible pathogenesis of aphasia induced by HUT, we reviewed the data of patients undergoing HUT in our hospital. 13 patients experienced transient aphasia in 3,488 cases. According to the hemodynamic changes, the incidence in vasodepressor, mixed, cardioinhibition and the negative response were 6.67, 5.52, 0 and 1.14 ‰ orderly, and not significantly different among the groups. It had significant difference between the positive response and the negative response and between vasodepressor and the negative response (both p < 0.05). The incidence in adults was significantly higher than that in children (<18 years) (p < 0.01), but not different between female and male. The average onset time was 11.33 ± 6.66 min (range 4-17 min) during baseline HUT or 4.90 ± 2.69 min (range 2-10 min) during sublingual nitroglycerin-provocated HUT. The duration was 3-60 min, except for one who was completely relieved of the disorder 4 h later. In conclusions, there is a risk of provoking transient aphasia during HUT. It reminds that performer should alert the possibility of transient aphasia during the test, especially when the patient is an adult and has a positive response.

[Clinical characteristics and treatment of 89 patients with head-up tilt table test induced syncope with convulsion].

OBJECTIVE: To study the clinical features and intervention strategies of head-up tilt table test (HUTT) induced syncope triggering convulsion. METHODS: HUTT was performed in 2377 cases (male 1116 cases and female 1261 cases) with syncope, dizziness, headache, chest tightness at Second Xiangya Hospital of Central South University from September 2000 to August 2011. They were 2.00-78.00 (18.57±14.36) years old, 1719 cases were younger than 18 years (the children group) [(2.00-17.92 (10.88±3.02) years] and 658 were older than 18 years (the adult group) [(18.00-78.00 (38.66±12.87) years]. We analyzed the related factors for inducing syncope triggering convulsion symptom and other serious side effects in HUTT. RESULTS: 1) Eighty-nine patients (3.74%) induced syncope with convulsion symptoms during HUTT, with more adults (62.92%) than children (37.08%) (χ(2)=87.842, P<0.01). 2) Sinus cardiac arrest and heart rate recovery time: 25 (28.09%) out of the 89 patients had sinus cardiac arrest. The sinus cardiac arrest time was 3.00-14.60 (7.90±3.44) s. After the HUTT, the heart rate recovery time was 0.50-37.00 (3.05±4.11) min, 70 of which (78.65%) resumed 3 min. 3) INTERVENTIONS: when all patients completed the HUTT, they would take oxygen and drink milk and other measures to relieve convulsions and recover heart rate and blood pressure. No one died, and the vital signs of 2 patients returned to normal after intravenous administration. CONCLUSION: Induced syncope triggering convulsion symptom in HUTT is more common in adult patients. Convulsions disappear and heart rate and blood pressure return to normal after taking oxygen and milk and other measures. HUTT in clinical practice is safe, and can be used in patients of all ages.

[Causes of unexplained syncope in children].

OBJECTIVE: To investigate the common causes of unexplained syncope in children. METHODS: A total of 434 children with unexplained syncope who were aged from 3.0 to 17.9 years (192 males and 242 females) and who saw the doctor between January 2006 and October 2011. were examined in order to explore the detailed histories and causes of syncope and to analyze variance in causes among different ages, genders, syncope frequencies and head-up tilt test (HUTT) results. RESULTS: (1) The causes of occasional syncope included persistent standing (30%), movement (13%), change in body position(9%), sitting(7%), and playing(6%). Persistent standing was more common as a cause in females than in males (P<0.01). Micturition syncope was mainly seen in males. Sultry weather was the main cause of syncope in females. Change in body position was a more common cause in the ≥12 years group than in the <12 years group (P<0.05), while other causes showed no significant differences among different age groups. Change in body position was a more common cause of syncope in children with negative HUTT results than in those with positive HUTT results (P<0.05). (2) All causes of occasional syncope can induce repeated syncope, and most repeated syncope (56%) had the same cause. CONCLUSIONS: The common causes of unexplained syncope include persistent standing, movement and changes of body position in children. Avoiding these causes is helpful for prevention of childhood syncope.

[Application of the head-up tilt table test in children under 6 years old].

OBJECTIVE: To study the clinical value and safety of the head-up tilt table test (HUTT) in children under 6 years old. METHODS: The HUTT results between September 2000 and August 2011 of 144 2 to 6-year-old children (81 boys and 63 girls) with syncope and dizziness of unknown causes were retrospectively studied. RESULTS: Eight children completed the based tilt table test and 136 cases completed the sublingual nitroglycerin tilt table test. No serious side effects were found in these children. Thirty-two (22.2%) of the 144 children had a positive result of HUTT, including 18 boys and 14 girls (P>0.05). When HUTT-induced syncope met positive standards, ECG record and blood pressure recovered to normal levels within 5 minutes by changing the position of the test bed, keeping the airway open, nasal oxygen inhalation and oral milk. CONCLUSIONS: The HUTT is valuable, safe and compliant in children under 6 years old.

[Differences between age and gender in patients with micturition syncope].

OBJECTIVE: To study the difference between age and gender in patients with micturition syncope (MS). METHODS: A total of 56 patients with MS were diagnosed from 1 542(3-72 years old) cases with unexplained syncope or symptoms of presyncope during micturition in our hospital. The age, onset age, positive rate of head up tilt table test (HUTT) and their correlation with age and gender were analyzed. RESULTS: The average age of patients with MS was older than that of patients with nonmicturition syncope (NMS)[5-67(35.5)years old vs. 3-72(12)years old,Z=-7.587,P<0.01]. Among the patients with MS, adults (>18 years old) were more than children (≤ 18 years old) (9.4% vs. 1.0%,χ2=65.689,P<0.01). There was gender difference in the onset rate of MS (male 5.0% vs. female 2.5%,χ 2=6.858,P<0.01). There was no difference in the positive rate of HUTT between the MS and NMS groups, and between the males and females with MS. There was no difference in age and onset age between the HUTT positive and negative group, and between the males and females. CONCLUSION: MS occurs more often in adults and males. Bezold Jazisch reflex may play a role in the mechanism of MS.

[Arrhythmia after a positive head-up tilt table test].

OBJECTIVE: to study the characteristics of arrhythmia after a positive head-up tilt table test (HUTT). METHODS: head-up tilt table test (BHUT) or sublingual nitroglycerin-provocation head-up tilt table test (SNHUT) were performed in 1374 patients at the Second Xiangya Hospital of Central South University from March of 2001 to August of 2009. Arrhythmias were recorded in 169 patients after a positive HUTT [57 male, age 6 - 65 years, 86 children < 18 years, mean age (23.1 ± 14.8) years]. RESULTS: arrhythmias developed in 75 patients (44.38%) post a positive BHUT and in 94 patients (55.62%) post a positive SNHUT. Major types of arrhythmias were sinus bradycardia (143/169, 84.62%), junctional escape rhythm (55/169, 32.54%) and sinus arrest (26/169, 15.38%). Sinus bradycardia was more common in adult (P < 0.01). Occurrence of junctional escape rhythm and sinus arrest was not affected by age, gender and test mode. Arrhythmia and the manifestation of syncope or pre-syncope occurred simultaneously in 77 (45.56%) patients and mainly in BHUT, while arrhythmia appeared later than the syncope manifestation in 92 (54.44%) patients and mainly in SNHUT (P < 0.05). Arrhythmia and blood pressure reduction occurred simultaneously in 84 (53.50%) cases and mainly in BHUT, while arrhythmia appeared later than reduction of blood pressure in 73 (46.50%) cases and mainly in SNHUT (P < 0.01). CONCLUSIONS: (1) the common types of arrhythmia were sinus bradycardia, junctional escape rhythm and sinus arrest after a positive HUTT. Occurrence of sinus arrest was not affected by age, gender and test mode. (2) In BHUT, arrhythmia occurred mostly simultaneously with the manifestation of syncope or pre-syncope and blood pressure reduction, while arrhythmia appeared later in SNHUT.

[Clinical analysis of vasovagal syncope in children].

OBJECTIVE: To study the changes in clinical features of vasovagal syncope (VVS) in children. METHODS: From January 2000 to September 2009, 841 children with unexplained syncope or prodromata were enrolled. They were assigned to two groups according to the period of visiting hospital: group A (from January 2000 to December 2004, n=129) and group B (from January 2005 to September 2009, n=712). They were assigned to three age groups: 4-6 years old, 7-10 years old and 11-18 years old. A head-up tilt table test (HUTT) was performed on all the subjects. RESULTS: The total positive rate of HUTT was 45.3% (381/841). Compared with that in group A, the positive rate of HUTT in group B increased significantly (47.5% vs 33.3%; P<0.05). The positive rate of HUTT in female children was significantly higher than that in male children (49.3% vs 37.9%; P<0.05). The positive rate of HUTT increased with age and it was the highest in children at age of 11-18 years (49.2%), followed by in children at age of 7-10 years (44.1%) and 4-6 years (37.1%) (P<0.05). The children at age of 7-10 years and 11-18 years from group B showed significantly higher positive rate of HUTT than those from group A (46.2% vs 27.8%; 54.0% vs 32.6%, P<0.05). Vasodepressor type was the most common response type (70.9%) shown by HUTT compared with mixed type (25.5%) and cardioinhibitory type (3.6%) (P<0.05). The proportion of children with vasodepressor response type in group B was significantly higher than that in group A (72.5% vs 58.1%; P<0.05). CONCLUSIONS: There were obvious changes in the prevalence of VVS and response types before and after five years, suggesting that the development of VVS may be attributed to many factors, such as social factors, mental factor and life style.

[Efficacy of midodrine hydrochloride in the treatment of children with vasovagal syncope].

OBJECTIVE: To explore the efficacy of midodrine hydrochloride in the treatment of vasovagal syncope (VVS) in children. METHODS: Forty-eight children with unexplained syncope and prodromata (21 males, 27 females, aged 6 -17 years, mean 11 years +/- 3 years) were randomly assigned into 3 groups. They were health education group, cresol group and midodrine hydrochloride group respectively. Cresol group was comprised of children given cresol as first-line therapy in addition to health education and midodrine hydrochloride group patients given midodrine hydrochloride on the basis of cresol group. Repeated head-up tilt testing (HUTT) and follow-ups of at least 6 months were conducted to evaluate the therapeutic efficacy, side effects of midodrine hydrochloride and hemodynamic changes in treating pediatric VVS. RESULTS: (1) The HUTT-based effective rate of 3 group was 20.0% (2/10), 60.9% (14/23) and 80.0% (12/15) respectively. It was significantly higher in cases of midodrine hydrochloride group and cresol group than that of health education group (P < 0.05). However,there was no significant difference in the HUTT-based effective rate between cresol group and midodrine hydrochloride group (P > 0.05). (2) During the follow-up period, the recurrence rate of syncope was significantly lower in midodrine hydrochloride group than in other two groups (P < 0.05). However, there was no significant difference in the recurrence rate of syncope between health education and cresol groups (P > 0.05). (3) There was no statistic difference in supine hemodynamic indices (HR, SBP, DBP) between before and after treatment in 3 groups. After midodrine therapy, the effects of midodrine upon changes in systolic and diastolic pressures and heart rate, between upright beginning and supine positions, were statistically significant (P <0.05). CONCLUSION: Health education and cresol are conventional therapies for pediatric VVS. The efficacy can be enhanced by supplementing midodrine hydrochloride. Such a regimen is effective and safe in treating pediatric VVS.