Holter Electrocardiographic Approach to Predicting Outcomes of Pediatric Patients With Long QT Syndrome.

BACKGROUND: This study was performed to clarify the clinical findings of pediatric patients diagnosed with long QT syndrome (LQTS) through electrocardiographic screening programs and to predict their outcome using Holter electrocardiographic approaches.Methods and Results: This retrospective study included pediatric patients with a Schwartz score of ≥3.5 who visited the National Hospital Organization Kagoshima Medical Center between April 2005 and March 2019. Resting 12-lead and Holter electrocardiograms were recorded at every visit. The maximum resting QTc and maximum Holter QTc values among all recordings were used for statistical analyses. To test the prognostic value of QTc for the appearance of cardiac events after the first hospital visit, receiver operating characteristic curves were used to calculate the area under the curve (AUC). Among 207 patients, 181 (87%) were diagnosed through screening programs. The prevalence of cardiac events after the first hospital visit was 4% (8/207). Among QTc at diagnosis, maximum resting QTc, and maximum Holter QTc, only maximum Holter QTc value was a predictor (P=0.02) of cardiac events after the hospital visit in multivariate regression analysis. The AUC of the maximum Holter QTc was significantly superior to that of maximum resting QTc. CONCLUSIONS: The maximum Holter QTc value can be used to predict the appearance of symptoms in pediatric patients with LQTS.

Developmental trajectories at a high risk for childhood overweight/obesity.

BACKGROUND: The associations between developmental patterns (trajectories) in children and maternal factors have been widely investigated, but paternal effects on these trajectories are unclear. This study aimed to determine child and parental factors involved in developmental trajectories at high risk for causing adverse cardiovascular (CV) profiles in children. METHODS: We analyzed longitudinal anthropometric data from birth to the present and CV profiles of 1,832 healthy volunteers (51% girls) aged 3-15 years who participated in a nationwide study between July 2012 and January 2014. Six trajectory latent class growth models were developed using body mass index z- scores. Predictors for being in developmental trajectories at high risk for causing adverse CV profiles were determined by multivariate regression analysis. RESULTS: The mean±standard deviation number of anthropometric data points was 12±3 for both boys and girls. Among the six trajectories, the infantile onset and continual increase groups had significantly worse levels of many CV profiles than those in the remaining groups. Paternal overweight/obesity was an independent predictor for boys being in the infantile onset group and for girls being in the continual increase group. Additionally, maternal pre-pregnancy overweight/obesity in boys and maternal excessive gestational weight gain in girls were independent predictors for being in the infantile onset group. Having no sibling in boys and an older maternal age were independent predictors for being in the continual increase group. CONCLUSIONS: Interventions to prevent childhood obesity should include strategies that focus on fathers and mothers as well as those that focus on children with certain types of familial background.

School-based routine screenings of electrocardiograms for the diagnosis of long QT syndrome.

AIMS: School-based routine screenings of electrocardiograms (ECGs) have been performed upon admission to primary school (PS), junior high school (JHS), and high school (HS) in Japan. Though ECGs with prolonged QT intervals are occasionally found, the role of regular ECG screening tests in identifying long QT syndrome (LQTS) remains to be determined. We investigated the usefulness of the ECG screenings by comparing the results of genetic tests between students who showed QT-prolongation in the screenings and patients with LQTS. METHODS AND RESULTS: We genetically screened 341 students (106 PS, 173 JHS, and 62 HS). Of these, 230 subjects showed QT-prolongation during regular screenings (S-S group), and the other 111 patients were clinically consulted with suspected LQTS by paediatricians (C-C group). Genotype-phenotype relationships were compared between the two groups. The positive rates in the genetic tests were comparable among the two groups; however, symptomatic subjects were significantly fewer in the S-S group than the C-C group (3% vs. 70%). Compared to the genotype-negative subjects, the positive subjects showed significantly longer QTc (P < 0.0001) and more frequently presented LQTS risk scores with ≥3.5 points (P < 0.0001). Lethal arrhythmic events (LAE) occurred only in the C-C group; 18 subjects experienced LAE and 83% of them were found to carry variant(s) in the LQTS-related genes. CONCLUSION: The school-based ECG screenings are effective in identifying young patients with LQTS who require genetic analysis. If individuals are screened at a younger age, we can identify patients at risk earlier and provide preventative treatments.

Loss-of-function mutations in cardiac ryanodine receptor channel cause various types of arrhythmias including long QT syndrome.

AIMS: Gain-of-function mutations in RYR2, encoding the cardiac ryanodine receptor channel (RyR2), cause catecholaminergic polymorphic ventricular tachycardia (CPVT). Whereas, genotype-phenotype correlations of loss-of-function mutations remains unknown, due to a small number of analysed mutations. In this study, we aimed to investigate their genotype-phenotype correlations in patients with loss-of-function RYR2 mutations. METHODS AND RESULTS: We performed targeted gene sequencing for 710 probands younger than 16-year-old with inherited primary arrhythmia syndromes (IPAS). RYR2 mutations were identified in 63 probands, and 3 probands displayed clinical features different from CPVT. A proband with p.E4146D developed ventricular fibrillation (VF) and QT prolongation whereas that with p.S4168P showed QT prolongation and bradycardia. Another proband with p.S4938F showed short-coupled variant of torsade de pointes (scTdP). To evaluate the functional alterations in these three mutant RyR2s and p.K4594Q previously reported in a long QT syndrome (LQTS), we measured Ca2+ signals in HEK293 cells and HL-1 cardiomyocytes as well as Ca2+-dependent [3H]ryanodine binding. All mutant RyR2s demonstrated a reduced Ca2+ release, an increased endoplasmic reticulum Ca2+, and a reduced [3H]ryanodine binding, indicating loss-of-functions. In HL-1 cells, the exogenous expression of S4168P and K4594Q reduced amplitude of Ca2+ transients without inducing Ca2+ waves, whereas that of E4146D and S4938F evoked frequent localized Ca2+ waves. CONCLUSION: Loss-of-function RYR2 mutations may be implicated in various types of arrhythmias including LQTS, VF, and scTdP, depending on alteration of the channel activity. Search of RYR2 mutations in IPAS patients clinically different from CPVT will be a useful strategy to effectively discover loss-of-function RYR2 mutations.

Novel electrocardiographic criteria for short QT syndrome in children and adolescents.

AIMS: Although shortening of the corrected QT interval (QTc) is a key finding in the diagnosis of short QT syndrome (SQTS), there may be overlap of the QTc between SQTS patients and normal subjects in childhood and adolescence. We aimed to investigate electrocardiographic findings for differentiation of SQTS patients. METHODS AND RESULTS: The SQTS group comprised 34 SQTS patients <20 years old, including 9 from our institutions and 25 from previous reports. The control group comprised 61 apparently healthy subjects with an QTc of <360 ms who were selected from 13 314 participants in a school-based screening programme. We compared electrocardiographic findings, including QT and Jpoint-Tpeak intervals (QT and J-Tpeak, respectively), those corrected by using the Bazett's and Fridericia's formulae (cB and cF, respectively) and early repolarization (ER) between the groups. QT, QTc by using Bazett's formula (QTcB), QTc by using Fridericia's formula (QTcF), J-Tpeak, J-Tpeak cB, and J-Tpeak cF were significantly shorter in the SQTS group than in the control group. On receiver operating characteristic curve analysis, the area under the curve (AUC) was largest for QTcB (0.888) among QT, QTcB, and QTcF, with a cut-off value of 316 ms (sensitivity: 79.4% and specificity: 96.7%). The AUC was largest for J-Tpeak cB (0.848) among J-Tpeak, J-Tpeak cB, and J-Tpeak cF, with a cut-off value of 181 ms (sensitivity: 80.8% and specificity: 91.8%). Early repolarization was found more frequently in the SQTS group than in the control group (67% vs. 23%, P = 0.001). CONCLUSION: A QTcB <316 ms, J-Tpeak cB < 181 ms, and the presence of ER may indicate SQTS patients in childhood and adolescence.

Electrocardiographic Diagnosis of Hypertrophic Cardiomyopathy in the Pre- and Post-Diagnostic Phases in Children and Adolescents.

BACKGROUND: The usefulness of electrocardiographic (ECG) voltage criteria for diagnosing hypertrophic cardiomyopathy (HCM) in pediatric patients is poorly defined.Methods and Results:ECGs at the 1st grade (mean [±SD] age 6.6±0.3 years) were available for 11 patients diagnosed with HCM at around the 7th grade (13.2±0.3 years). ECGs were available for another 64 patients diagnosed with HCM in the 1st (n=15), 7th (n=32), and 10th (n=17) grades. Fifty-one voltage criteria were developed by grade and sex using 62,841 ECGs from the general population. Voltage criteria were set at the 99.95th percentile (1/2,000) point based on the estimated prevalence of childhood HCM (2.9 per 100,000 [1/34,483]) to decrease false negatives. Conventional criteria were from guidelines for school-aged children in Japan. Of 11 patients before diagnosis, 2 satisfied conventional criteria in 1st grade; 5 (56%) of the remaining 9 patients fulfilled 2 voltage criteria (R wave in limb-lead I [RI]+S wave in lead V3 [SV3] and R wave in lead V3 [RV3]+SV3). Robustness analysis for sensitivity showed RV3+SV3 was superior to RI+SV3. For all patients after diagnosis, RI+SV4 was the main candidate. However, conventional criteria were more useful than voltage criteria. CONCLUSIONS: Early HCM prediction was possible using RV3+SV3 in >50% of patients in 1st grade. Voltage criteria may help diagnose prediagnostic or early HCM, and prevent tragic accidents, although further prospective studies are required.

Diagnostic value of P-waves in children with idiopathic restrictive cardiomyopathy.

Restrictive cardiomyopathy (RCM) is a rare myocardial disease with an impaired diastolic function and poor prognosis. Almost all RCM patients are reported to have abnormal P-waves due to atrial overloading. This study aimed to reveal the characteristics of the P-waves in RCM patients and to suggest the diagnostic index of RCM in children with a 12-lead electrocardiogram (ECG). We retrospectively investigated 17 ECGs of children with idiopathic RCM during the initial visit at 15 institutes in Japan between 1979 and 2013. The RCM group was divided into four groups based on the age (elementary school [ES] and junior high school [JHS] students) and inception of the diagnosis (abnormal ECG on school-heart-screening [e-RCM] and some cardiovascular symptoms [s-RCM]), the ES/e-RCM (n = 5), ES/s-RCM (n = 4), JHS/e-RCM (n = 4), and JHS/s-RCM (n = 4) groups. As an aged-match control group, school-heart-screening ECGs of 1st-grade ES students (16,770 students) and 1st-grade JHS students (18,126 students) from Kagoshima in 2016 were adopted. For a comparison between the groups, we used the effect size "Hedge's g" by calculating the mean and standard deviation of the two groups. An effect size of 0.8 (or above) had an overlap of 53% (or less). The effect sizes of the sum of the absolute values of the forward and backward amplitudes in lead V1 (P1 + P2 V1) was the largest, and the ES/e-RCM, ES/s-RCM, JHS/e-RCM, and JHS/s-RCM were 15.8, 22.1, 9.4, and 10.3, respectively. A P1 + P2 V1 > 200 µV was able to rule in all RCM patients, thus, we proposed 200 µV as the cutoff value for screening purposes. In conclusion, the P1 + P2 V1 in the school-heart-screening may be useful for detecting asymptomatic or early-stage RCM in school-age children.

Sudden out-of-hospital cardiac arrest in pediatric patients in Kyushu area in Japan.

BACKGROUND: It is well-known that a neurologically favorable outcome of out-of-hospital cardiac arrest (OHCA) is associated with the presence of bystander-initiated cardiopulmonary resuscitation (bystander CPR) and use of an automated external defibrillator. However, little is known about the effect of the presence of pre-existing conditions, prior activity, and locations on the outcome of pediatric OHCA. METHODS: We analyzed the data from questionnaires about pediatric patients with OHCA aged from 3 days to 19 years in the Kyushu area in Japan between 2012 and 2016. RESULTS: A total of 594 OHCA cases were collected. The numbers of OHCA cases and the rate of 1 month survival with a favorable neurological outcome during sleeping, swimming / bathing, and exercise were 192 (1.0%), 83 (32.5%), and 44 (65.9%), respectively. When an OHCA occurred at school (n = 56), 88% of children / adolescents received bystander CPR, but when it occurred at home (n = 390), 15% received bystander CPR. Cardiovascular (n = 61), suicide (n = 61), and neurological / neuromuscular (n = 44) diseases were three major pre-existing conditions. The OHCA of cardiovascular disease was associated with exercise (24/61) and mainly occurred at school (22/61). The OHCA of neurological / neuromuscular disease was associated with swimming/bathing (15/44) and mainly occurred during bathing at home (12/44). Multivariate regression analysis showed that the presence of bystander CPR (P < 0.001) and occurrence of OHCA at school (P < 0.001) were independently predictive of a favorable outcome in pediatric OHCA. CONCLUSION: The outcome was different among pre-existing conditions, prior activity, and location of OHCA. These findings might be useful for preventing OHCA and improving the outcome of pediatric OHCA.

A significance of school screening electrocardiogram in the patients with ventricular noncompaction.

Left ventricular noncompaction (LVNC) is a hereditary cardiomyopathy and is associated with high morbidity and mortality. However, the role and significance of school screening for LVNC have not been fully elucidated. In this multicenter, retrospective cohort study, a total of 105 children with LVNC were included from 2000 to 2017. At the initial presentation, 44 patients (41.9%) were diagnosed by school screening. One (1.0%) patient underwent heart transplantation and four (3.8%) patients died during the study. Electrocardiogram data showed a high prevalence of fragmented QRS (33.4%) and J wave (15.7%). Treatments were needed in eight (18.2%) patients who were detected by school screening. The multivariable proportional hazards model showed T-wave abnormality on electrocardiogram in first graders was independent risk factors for major adverse cardiac events (odds ratio 4.94, p value = 0.0007). Moreover, dilation of the left atrium on chest X-ray and low ejection fraction on echocardiogram at the initial treatment were independent risk factors for treatment (odds ratio 1.7 × 107 and 22.3, p = 0.0362 and 0.0028, respectively). This study is the first report focusing on school screening in a large pediatric cohort with LVNC. With the use of abnormalities in electrocardiogram, school screening may be a good detector of and predictor for LVNC.

Multivariate analysis of TU wave complex on electrocardiogram in Andersen-Tawil syndrome with KCNJ2 mutations.

BACKGROUND: The exact differences between the TU wave complex of ATS1 and that of healthy individuals remain to be investigated. We sought to characterize the TU wave complex of Andersen-Tawil syndrome type 1 (ATS1) using high frequency electrocardiogram (ECG) data. METHODS: Electrocardiograms were recorded as time series data with a 2 kHz frequency ECG amplifier in 13 patients with ATS1 (positive for KCNJ2 mutation, ATS1 group) and age-matched healthy individuals (control group). Conventional ECG parameters were measured, and principal component analysis (PCA) and independent component analysis (ICA) were applied to the TU wave complex. RESULTS: Time from T peak (Tp) to U peak (Up), time from bottom (B) to Up, and time from B to U end (BUe, U duration) (0.232 ± 0.018 vs. 0.165 ± 0.017, p < .0001), where B is the lowest point between T and U waves, were all longer in the ATS1 group than the control group. Multivariate logistic regression analysis revealed that BUe could completely differentiate the two groups. PCA ratios in the ATS1 group were significantly larger than the control group (26.5 ± 12.3 vs. 10.4 ± 6.2, p = .0005). ICA revealed 1 or 2 U-wave-specific independent components (ICs) that exclusively comprise the U wave in ATS1, whereas U waves in the control group were composed of some ICs that also comprised T waves. CONCLUSIONS: U-wave-related temporal parameters, particularly BUe, and the existence of U-wave-specific ICs, extracted in the ICA, are useful for differentiation of U waves in ATS1 from those in healthy individuals.

Promoting physical activity through walking to treat childhood obesity, mainly for mild to moderate obesity.

BACKGROUND: There are no randomized controlled trials examining the effect of walking on childhood obesity. METHODS: A randomized controlled trial was conducted between August 2014 and April 2015 in Japan. Elementary school children aged 6 to 12 years with a percentage overweight (%OW) of ≥20% were recruited. One hundred and ninety children wanted to participate in the program, and all were accepted. After viewing a video that promoted physical activity through walking, participants were randomly assigned to three groups: walking (≥10 000 steps on school holidays), limiting screen time (<90 min on weekdays and <150 min on school holidays), and a control group (no intervention). The primary outcome was a decrease in %OW after 3 months' intervention. Per protocol analysis was performed using 156 participants who fulfilled the inclusion criteria of a %OW ≥20%. RESULTS: The mean %OW was 35 ± 7% before intervention. The mean reduction in %OW after intervention in the walking (n = 59), limiting ST (n = 46), and control (n = 51) groups were -4.06 ± 4.84, -1.97 ± 4.62, and -1.81 ± 3.64 percentage points, respectively. Reduction in %OW was significantly larger in the walking group than in the control group: adjusted mean difference, -2.18 percentage points (95% confidence interval, -3.85 to -0.52), P = 0.002. The intervention in children also had favorable effects on the lifestyles of their parents. The intention-to-treat analysis of all 190 participants showed comparable results. CONCLUSION: Promoting physical activity through walking on school holidays may be an additional strategy for treating elementary school children with obesity.

Tentative Screening Criteria for Short QT Interval in Children and Adolescents.

BACKGROUND: While the prevalence of short QT syndrome (SQTS) in children and adolescents is low, early detection is important because SQTS can cause life-threatening arrhythmia. The aim of this study was to determine the tentative screening criteria for short QT interval in children and adolescents. Methods and Results: A total of 75,040 digitally stored electrocardiograms (ECG) of participants in a school-based ECG screening program were obtained between 2009 and 2013 in Kagoshima, Japan. ECG with a corrected QT interval (QTc) below the 10th percentile for each grade and sex were selected: 2,581 first graders (M/F, 1,296/1,285); 2,792 7th graders (M/F, 1,400/1,392); and 2018 10th graders (M/F, 979/1,039). Three consecutive QT/RR intervals were manually measured and corrected using Bazett's formula. The prevalence of SQTS was estimated at 1/30,000-1/10,000, which was set compared with the prevalence of long QT syndrome, then the screening points of the prevalence of short QT interval were assumed to be between 1/5,000 and 1/2,000 to exclude the possibility of false negative. We obtained the following tentative criteria based on frequency distribution charts: 325, 315 and 305 ms for male 1st, 7th and 10th graders, respectively; and 320 ms for female 1st, 7th, and 10th graders. CONCLUSIONS: For primary SQTS screening of children and adolescents, the QTc values for short QT interval should be adapted according to grade and sex.

Autonomic Function and QT Interval During Night-Time Sleep in Infant Long QT Syndrome.

BACKGROUND: Sudden infant death syndrome mainly occurs during night-time sleep. Approximately 10% of cases are thought to involve infants with long QT syndrome (LQTS). Autonomic function and QT interval in night-time sleep in early infancy in LQTS infants, however, remain controversial.Methods and Results:Holter electrocardiography was performed in 11 LQTS infants before medication in early infancy, and in 11 age-matched control infants. Control infants were re-evaluated in late infancy. The power spectral density was calculated and parasympathetic activity and sympathovagal balance were obtained. Electrocardiograms of a representative hour during night-time sleep, daytime sleep, and daytime activity, were chosen and QT/RR intervals were manually measured. LQTS infants had significantly lower parasympathetic activity and higher sympathovagal balance during night-time sleep than control infants in early infancy. These autonomic conditions in early infancy were significantly depressed compared with late infancy. Corrected QT interval (QTc) during night-time sleep (490±20 ms) was significantly longer than that in daytime sleep (477±21 ms, P=0.04) or daytime activity (458±18 ms, P=0.003) in LQTS infants, and significantly longer than that during night-time sleep in controls. CONCLUSIONS: A combination of the longest QTc and autonomic imbalance during night-time sleep in early infancy may be responsible for development of life-threatening arrhythmia in LQTS infants. Critical cases should be included in future studies.

Standard Values and Characteristics of Electrocardiographic Findings in Children and Adolescents.

BACKGROUND: Reference values and the characteristics of the electrocardiographic (ECG) findings using a large number of subjects are lacking for children and adolescents.Methods and Results:A total of 56,753 digitally stored ECGs of participants in a school-based ECG screening system were obtained between 2006 and 2009 in Kagoshima, Japan. Each ECG was manually reviewed by 2 pediatric cardiologists and only ECGs with sinus rhythm were included. A final total of 48,401 ECGs from 16,773 1st (6 years old, 50% girls), 18,126 7th (12 years old, 51% girls), and 13,502 10th graders (15 years old, 52% girls) were selected. ECG variables showed differences in age and sex. However, the effects of age and sex on ECG variables such as the PQ interval, QRS voltage, and STJ segment were also different. The 98th percentile values of well-known surrogate parameters for ventricular hypertrophy in the present study were much higher than the conventional criteria. CONCLUSIONS: The present study of a large number of pediatric subjects showed that the effects of age and sex on ECG parameters are different, and that criteria for ventricular hypertrophy should be newly determined by age and sex. We have developed reference data for STJ segment elevation for children and adolescents. These findings are useful for creating guidelines and recommendations for interpretation of pediatric ECG.

Probability of diagnosing long QT syndrome in children and adolescents according to the criteria of the HRS/EHRA/APHRS expert consensus statement.

AIMS: The present study aimed to determine the probability of diagnosing long QT syndrome (LQTS) in children and adolescents based on the HRS/EHRA/APHRS criteria for LQTS. We used data of a school-based electrocardiographic screening programme in Japan. METHODS AND RESULTS: The total numbers of subjects who participated in the screening programme between 2008 and 2013 in Kagoshima, Japan, were 33 051 first- and 34 751 seventh-grade students, aged 6 and 12 years, respectively. The screening process consisted of three steps of examination: the first screening, and the second and third examinations. Among the total subjects, 32 982 first graders (99.8% of the total) and 34 572 seventh graders (99.5% of the total) participated in the first screening. After the first, second, and third screening or examinations, the programme determined 10 first and 32 seventh graders as having a high probability of LQTS according to the HRS/EHRA/APHRS criteria for LQTS. The probability of diagnosing LQTS by the screening programme was 1:3298 (0.30/1000) and 1:1080 (0.93/1000) in first and seventh graders, respectively. During the study periods, three subjects of 7th graders were already diagnosed as having LQTS at the first grade. Therefore, the overall probability of diagnosing LQTS was 1:3298 (95% confidence interval, 1:2036 to 1:8673) and 1:988 (95% confidence interval, 1:742 to 1:1477) in first and seventh graders, respectively. CONCLUSION: This study shows important data on the probability of diagnosing LQTS as ∼1:3300 in subjects aged 6 years and 1:1000 in those aged 12 years based on the HRS/EHRA/APHRS criteria.

Environmental risk factors for sudden infant death syndrome in Japan.

While the prevalence of sudden infant death syndrome (SIDS) has decreased worldwide, this decline has plateaued recently. Strategies are needed to resume the constant decrease of SIDS in Japan. A prospective electrocardiographic screening program for infants was performed between July 2010 and March 2011. Parents of 4319 infants were asked about environmental factors related to SIDS through questionnaires at a one-month medical checkup and one year. Parental awareness of prone position, smoke exposure, and breast feeding as environmental factors were 81.4 %, 69.0 %, and 47.8 %, respectively. The prevalence of laying infants exclusively in a supine position was 96.7 %. At the one-month medical checkup, smoking prevalence was 41.7 % in fathers and 2.1 % in mothers. Maternal smoking prevalence was significantly increased at one year after (p < 0.001). Multivariate regression analysis showed that risk factors for new or continued maternal smoking habits were maternal smoking habits at one month (p < 0.001), paternal smoking habits one year later (p < 0.001), and younger maternal age (p = 0.02). CONCLUSION: Most parents already avoid laying infants in the prone position, and parental smoking is still a SIDS risk concern in Japan. Smoking cessation programs should be further implemented for parents to decrease risks of SIDS in Japan. What is Known: • The prevalence of sudden infant death syndrome (SIDS) has decreased worldwide, however, this decline has plateaued recently. What is New: • Most infants were laid sleeping in the supine position (96.7 %) and were fed breast milk or a mix of expressed milk and formula (92.7 %), and 2.1 % of mothers smoked at the one-month medical checkup. • Maternal smoking prevalence significantly increased from the one-month medical checkup to one year later, and smoking mothers were more likely to feed infants by formula rather than breast milk. • Independent risk factors for new or continued maternal smoking habits included younger maternal age, maternal smoking habits at one month, and paternal smoking habits one year later.

Combination of flecainide and propranolol for congenital junctional ectopic tachycardia.

Congenital junctional ectopic tachycardia is a rare tachyarrhythmia with high mortality. A pharmacological approach in early infancy is regarded as the first-line therapeutic option. Pharmacologically, amiodarone alone or in combination with other drugs is the most commonly reported effective agent for congenital junctional ectopic tachycardia, but it has many adverse effects. Here we report the case of a 40-day-old infant. The clinical course suggests that combined oral flecainide and propranolol is an effective alternative therapy for early infants. Esophageal lead electrocardiography may give a clear diagnosis of junctional ectopic tachycardia.

Circumstances and outcomes of out-of-hospital cardiac arrest in elementary and middle school students in the era of public-access defibrillation.

BACKGROUND: Circumstances and outcomes of out-of-hospital cardiac arrest (OHCA) in elementary and middle school students while at school in the era of public-access defibrillation are unknown. METHODS AND RESULTS: We conducted a nationwide hospital-based survey of elementary and middle school students who had had OHCA of cardiac origin and received prehospital resuscitation in 2005-2009. Among 58 cases recruited, 90% were witnessed by bystanders; 86% had ventricular fibrillation as the initial rhythm; 74% were resuscitated by bystanders; 24% were defibrillated by bystanders; 55% occurred at school; 66% were exercise-related; 48% were followed up before the event; 67% had structural heart disease. In total, 53% of overall patients and 79% of those initially defibrillated by bystanders had a favorable neurological outcome. Patients were more likely to be defibrillated by bystanders (38% vs. 8%, P=0.012) and had a more favorable neurological outcome in schools (69% vs. 35%, P=0.017) than in other locations. The majority of arrests in schools were exercise-related (84% vs. 42%, P=0.001), occurred at sports venues, and students were resuscitated by teachers; half of the cases at school occurred in patients with a pre-event follow-up. CONCLUSIONS: After OHCA, children were more likely to be defibrillated by bystanders and had a better outcome in schools than in other locations, which may be relevant to the circumstances of events.