Electrocardiographic Changes with Age in Japanese Patients with Noonan Syndrome.

Little information is available on age-related electrocardiographic changes in patients with Noonan syndrome. This single-center study evaluated the electrocardiograms of patients with Noonan syndrome. We divided the patients (n = 112; electrocardiograms, 256) into four groups according to age: G1 (1 month-1 year), G2 (1-6 years), G3 (6-12 years), and G4 (>12 years). Typical Noonan syndrome-related electrocardiographic features such as left-axis deviation, abnormal Q wave, wide QRS complex, and small R wave in precordial leads were detected. A high percentage of QRS axis abnormalities was found in all groups. Significant differences in right-axis deviation (RAD) were noted among the groups: 56.5% of G1 patients showed RAD compared with 33.3% of G2, 21.1% of G3, and 19.2% of G4 patients. The small R was also significantly different among the groups: 32.6% of G1 patients showed a small R wave compared with 14.9% of G2, 8.5% of G3, and 15.4% of G4 patients. Of the 53 patients with Noonan syndrome aged 1 month to 2 years, 18 had T-positive V1 with a higher prevalence of pulmonary stenosis and cardiac interventions. QRS axis abnormalities, small R in V6, and T-positive V1 could help diagnose Noonan syndrome in infants or young children.

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.

Leucine-rich alpha-2-glycoprotein 1 and angiotensinogen as diagnostic biomarkers for Kawasaki disease.

OBJECTIVE: Kawasaki disease (KD) is a systemic vasculitis in childhood that can lead to coronary artery lesions (CALs). Although early diagnosis and treatment is important for preventing KD patients from development of CALs, diagnosis depends on the clinical features of KD. We studied the usefulness of leucine-rich alpha-2-glycoprotein 1 (LRG1) and angiotensinogen (AGT), previously reported as KD-related proteins, for KD diagnosis and estimation of intravenous immunoglobulin (IVIG) efficacy. METHODS: We undertook a prospective cohort study with patients having two or more KD symptoms in multiple centers in Japan, between July 2017 and February 2019. RESULTS: Two hundred forty-two patients were included. In multivariable analysis, one unit increase in LRG1 was associated with higher odds of KD diagnosis (Odds ratio [OR] 1.02 [95% confidence interval (CI) 1.001-1.03]). Double-positivity for AGT (≥ 26 µg/mL) and LRG1 (≥ 123.5 µg/mL) was an independent biomarker for KD diagnosis in both the total cohort and the subgroup of patients with two to four KD symptoms (OR 5.01 [95% CI 1.86-13.50] and 3.71 [95% CI 1.23-11.16], respectively). There was no association between LRG1/AGT and IVIG efficacy. CONCLUSION: Double-positivity for LRG1 and AGT is an biomarker for KD diagnosis, especially useful in diagnosing incomplete KD from non-KD. Future studies with larger cohorts should seek to determine whether LRG1 and AGT are valuable as definitive data referred at the diagnosis of KD and for estimating the risk of CALs.

A case of multisystem inflammatory syndrome in children in a Japanese boy: with discussion of cytokine profile.

The new disease concept of multisystem inflammatory syndrome in children (MIS-C), which is a systemic inflammatory syndrome with multiple organ involvement after SARS-CoV2 infection, was established in 2020. MIS-C is common in Hispanic and black children in Europe and North America, with few reports in East Asians. A significant portion of patients with MIS-C develop Kawasaki disease (KD)-like symptoms. Therefore, differential diagnosis is challenging, especially in East Asia, where KD is most prevalent. No Japanese cases have been reported in the literatures so far. We report a case of MIS-C in Japan with KD-like symptoms. A 9-year-old Japanese boy, who was infected with SARS-CoV2 1 month previously along with his family, was admitted to our hospital owing to fever for 6 d and erythema mainly in the groyne and pubic area. He also had conjunctivitis, strawberry tongue and diarrhoea. His laboratory findings were as follows: WBC, 12,840/µL (lymphocytes, 4%); CRP, 22.6 mg/dL, pro-calcitonin, 1.8 ng/mL (normal, <0.50 ng/mL); NT pro-BNP, 7627 pg/mL (<125 pg/mL); and troponin T, 0.14 ng/mL (<0.01 ng/mL). His cardiac function was normal. We initially diagnosed him with KD. His fever rapidly resolved with intravenous immunoglobulin (IVIG) and there were no coronary artery lesions. Desquamation of the fingers was observed later. Finally, a history of SARS-COV2 infection, his age, atypical skin rash, elevation of markers of inflammation and heart failure and lymphopenia suggested the diagnosis of MIS-C rather than KD. Differentiation between KD and MIS-C is necessary even in Japan, especially in patients with atypical features of KD.

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.

Impact of the T-wave characteristics on distinguishing arrhythmogenic right ventricular cardiomyopathy from healthy children.

BACKGROUND: T-wave inversion (TWI) is not considered useful for diagnosing pediatric arrhythmogenic right ventricular cardiomyopathy (ARVC), because right precordial TWI in ARVC resembles a normal juvenile pattern. OBJECTIVES: The aims of this study were to clarify the electrocardiographic (ECG) characteristics of pediatric ARVC to distinguish those patients from healthy children. METHODS: Between 1979 and 2017, 11 ARVC patients under 18 years old were registered and compared with school screening ECGs from 48,401 healthy children. RESULTS: The mean age at the first arrhythmic event or diagnosis was 13.3 ± 4.7 years. Nine patients were asymptomatic initially and were found by ECG screening, but 6 developed severe symptoms during the follow-up. Healthy children had a normal juvenile pattern, while ARVC children, especially symptomatic patients, had a significant tendency to have inferior and anterior TWI. The phenomenon of T-wave discontinuity (TWD) in which the TWI became deeper from V1 to V3 and suddenly turned positive in V5 was significantly more frequent in ARVC (60%) than healthy children (0.55%). Anterior TWI and TWD were also significantly more frequent in those who developed severe symptoms. The sensitivity and specificity of TWD were 60% (95% CI, 31-83%), and 99% (95% CI, 99-99%) to distinguish ARVC from healthy children, as well as 100% (95% CI, 71-100%) and 80% (95% CI, 51-80%), respectively, to predict severe symptoms in the future. CONCLUSIONS: The ECG is useful to distinguish ARVC children, even in the early phase. Anterior TWI and TWD could detect ARVC children and to predict the possible serious conditions.

Fully automated rapid quantification of Hepatitis C Virus RNA in human plasma and serum by integrated on-chip RT-qPCR and capillary electrophoresis.

The quantification of hepatitis C virus (HCV) is essential for the management of chronic hepatitis C therapy. We have developed a fully automated microfluidic RT-qPCR system for rapid quantitative detection of HCV RNA in human EDTA-plasma and serum, and the performance of the method was assessed. The platform for the assay, µTASWako g1 Fully Automated Genetic Analyzer, performs automated sample preparation and RNA extraction, followed by amplification and detection on an integrated RT-qPCR-CE (capillary electrophoresis (CE)) microfluidic chip. The total assay time from sample input to data output is less than 120 minutes. The HCV assay has a linear quantitative range of 15 to 107 IU/mL, with a limit of detection (LOD) of 10.65 IU/mL in EDTA-plasma and 12.43 IU/mL in serum. The assay has a reproducibility of SD ≤ 0.16 log10 IU/mL and an accuracy of ≤ 0.22 log10 IU/mL difference when compared to the assigned values. The main HCV genotypes 1 to 6 are detected with an accuracy of ± 0.3 log10 IU/mL. The assay is specific for HCV RNA and is free of interference from non-HCV pathogens, elevated levels of anti-viral and anti-bacterial drugs, and common endogenous interferents. In the linear quantitative range, the assay is highly correlated with the Roche cobas AmpliPrep/cobas TaqMan HCV Test, version 2.0 (r2 = 0.949). As the assay is highly sensitive, accurate and specific, and provides reliable quantification of HCV in plasma and serum, it can potentially be applicable for monitoring the therapy and management of HCV infection.

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.

Pharmacologic therapy with flecainide for asymptomatic Wolff-Parkinson-White syndrome in an infant with severe left ventricular dyssynchrony.

Some asymptomatic patients with Wolff-Parkinson-White syndrome have severe left ventricular dyssynchrony and dysfunction. We describe a patient who was given a diagnosis of Wolff-Parkinson-White syndrome in infancy and had a complete response to pharmacologic therapy with flecainide. Our findings suggest that flecainide is a suitable resynchronisation therapy for such infants.

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.

Study design for control of HEART rate in inFant and child tachyarrhythmia with heart failure Using Landiolol (HEARTFUL): A prospective, multicenter, uncontrolled clinical trial.

BACKGROUND: Persistent tachycardia in pediatric patients after congenital heart surgery further deteriorates their hemodynamic condition, and may become fatal. Therefore, immediate control of the tachycardia is mandatory in these patients. For this purpose, quick-acting, short-acting, titratable intravenous agents are required. However, there are no agents with such characteristics among the drugs approved for control of pediatric arrhythmias in Japan, and thus novel and effective medications for these patients are awaited. Landiolol, an ultrashort-acting ß-blocker, was approved in 2013 for tachyarrhythmias in adult patients with heart failure. However, its efficacy and safety in pediatric patients remain unclear. The aim of this prospective, multicenter, open-label phase IIb/III study is to investigate the efficacy and safety of landiolol in pediatric patients with tachyarrhythmias as well as heart failure. METHODS: Eligible patients are aged ≥ 3 months and <15 years, and have tachyarrhythmia (atrial fibrillation, atrial flutter, supraventricular tachycardia) as well as heart failure. The primary endpoint of the study is ≥20% reduction from baseline heart rate or return to normal sinus rhythm within 2h after starting intravenous administration of landiolol. Patients will receive intravenous infusion of landiolol, starting at 1µg/kg/min. The dose will be increased by 1µg/kg/min every 15-20min until the tachycardia rate has decreased by >20% or tachycardia has terminated, and the dose will then be maintained or further increased depending on the patient's condition. The study was started in April 2015 and will end within a few years. CONCLUSIONS: The study was designed and designated the "HEARTFUL study" in the hope of establishing a basis for control of HEART rate in inFant and child tachyarrhythmia Using Landiolol in children with heart failure.

Effect of VKORC1, CYP2C9, CFP4F2, and GGCX Gene Polymorphisms on Warfarin Dose in Japanese Pediatric Patients.

BACKGROUND: Warfarin dosage requirements show considerable inter-individual variability. There are some reports of warfarin dose regimens correlating with single nucleotide polymorphisms (SNP) for CYP2C9, VKORC1 and other genes in adults. In children, however, reports are scarcer than in adults and the number of genes examined is more limited. We explored the effects of genetic variation on warfarin dose requirement in Japanese pediatric patients. METHODS: A total of 45 patients who were prescribed warfarin at the Yokohama City University Hospital were included in this study. The influence of genetic polymorphisms on stable warfarin dosage requirement was investigated by genotyping SNPs of the VKORC1, CYP2C9, CYP4F2, and GGCX genes (rs9923231, rs1057910, rs2108622, and rs699664, respectively) in each patient. RESULTS: Patients with the TT genotype in rs9923231 in VKORC1 required significantly lower maintenance dosages than those with the TC genotype (p = 0.001). Multiple regression analysis showed that, while VKORC1 status and patient height account for 78.2 % of the variability in maintenance warfarin dosage, genetic polymorphisms in VKORC1 account for 27 %, although polymorphisms in CYP4F2 and GGCX had no effect on dosage and the effect of CYP2C9 could not be evaluated. CONCLUSIONS: Polymorphisms in VKORC1 partially affected daily warfarin dosage requirements. VKORC1 genotype and height are the primary determinants influencing warfarin dosage in Japanese pediatric patients. Further studies with larger sample sizes are needed to confirm our results.

Usefulness of real-time three-dimensional trans-oesophageal echocardiography for detection of isolated unroofed coronary sinus.

We report a case of unroofed coronary sinus not associated with the persistent left superior vena cava. Definite diagnosis of the unroofed coronary sinus was obtained by trans-oesophageal echocardiography, which revealed the unroofed portion with left-to-right shunt. Real-time three-dimensional trans-oesophageal echocardiography could show the whole pictures of the defect, which was useful information for surgical repair.

Direct measurement of a patient's entrance skin dose during pediatric cardiac catheterization.

Children with complex congenital heart diseases often require repeated cardiac catheterization; however, children are more radiosensitive than adults. Therefore, radiation-induced carcinogenesis is an important consideration for children who undergo those procedures. We measured entrance skin doses (ESDs) using radio-photoluminescence dosimeter (RPLD) chips during cardiac catheterization for 15 pediatric patients (median age, 1.92 years; males, n = 9; females, n = 6) with cardiac diseases. Four RPLD chips were placed on the patient's posterior and right side of the chest. Correlations between maximum ESD and dose-area products (DAP), total number of frames, total fluoroscopic time, number of cine runs, cumulative dose at the interventional reference point (IRP), body weight, chest thickness, and height were analyzed. The maximum ESD was 80 ± 59 (mean ± standard deviation) mGy. Maximum ESD closely correlated with both DAP (r = 0.78) and cumulative dose at the IRP (r = 0.82). Maximum ESD for coiling and ballooning tended to be higher than that for ablation, balloon atrial septostomy, and diagnostic procedures. In conclusion, we directly measured ESD using RPLD chips and found that maximum ESD could be estimated in real-time using angiographic parameters, such as DAP and cumulative dose at the IRP. Children requiring repeated catheterizations would be exposed to high radiation levels throughout their lives, although treatment influences radiation dose. Therefore, the radiation dose associated with individual cardiac catheterizations should be analyzed, and the effects of radiation throughout the lives of such patients should be followed.

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.

Bisphosphonate-related enamel hypoplasia in a child with idiopathic arterial calcification of infancy.

We report bisphosphonate-related enamel hypoplasia as a rare side effect in a child with idiopathic arterial calcification of infancy.