Ultrahigh density atrio-ventricular dual-chamber mapping as a next generation tool for ablation of accessory pathways.

INTRODUCTION: Detailed three-dimensional (3D) mapping has been useful for effective radiofrequency catheter ablation. The Rhythmia system can create atrio-ventricular dual-chamber mapping, which reveals the atrial and ventricular potentials all at once in the same map. The aim of this study was to investigate the utility of mapping the atrium and ventricle simultaneously with a high-density 3D mapping system for the ablation of accessory pathways (AP). METHODS: From July 2015 to August 2020, 111 patients underwent ablation of APs. Dual-chamber maps were created in 50 patients (median age 15 [10-54], 32 male [64.0%]), while 61 patients underwent radiofrequency (RF) ablation with conventional single-chamber 3D maps. The background characteristics and procedural details were compared between the dual-chamber mapping group and the conventional single-chamber mapping group. RESULTS: The number of RF applications (median [IQR]; 1.0 [1.0-3.0] vs. 3.0 [1.0-6.0], p = .0023), RF time (median [IQR], s; 9.2 [2.0-95.7] vs. 95.6 [4.1-248.7], p = .0107), and RF energy (median [IQR], J; 248.4 [58.7-3328.2] vs. 2867.6 [134.2-7728.4], p = .0115) were significantly lower in the dual-chamber group. The fluoroscopy time (median [IQR], min; 19.9 [14.2-26.1] vs. 26.5 [17.7-43.4], p = .0025) and fluoroscopy dose (median [IQR], mGy; 52.5 [31.3-146.0] vs. 119.0 [43.7-213.5], p = .0249) were also significantly lower in the dual-chamber than single-chamber mapping group. CONCLUSION: The dual-chamber mapping was useful for ablating accessory pathways and reducing the number of RF applications, total RF energy, and radiation exposure as compared with traditional mapping techniques.

The Impact of the Pulmonary Artery Index and Aortopulmonary Collateral Artery Coil Embolization on Intractable Pleural Effusions After a Fontan Surgery.

An intractable pleural effusion is a common comorbidity of a Fontan operation, occasionally leading to undesirable outcomes. The preventive effect of aortopulmonary collateral (APC) coil embolization against a pleural effusion before a Fontan operation is still controversial.This is a retrospective single-center study; among 227 Fontan cases, 57 cases with complete MRI data were analyzed at first. Factors associated with the duration of pleural drainage (median: 6 (2-41) days) and that of postoperative hospital stay (median: 25 (14-91) days) were analyzed using a multiple regression analysis. The pulmonary artery index (PAI; Nakata index) was associated with both the pleural drainage duration (P < 0.05, r2 = 0.17) and postoperative hospital stay (P < 0.05, r2 = 0.10).Thereafter, all the 227 patients were classified into the following three groups: Group A (12 patients in whom the embolization was performed within 30 days before the Fontan surgery), Group B (131 patients in whom the embolization was performed more than 30 days before the Fontan surgery), and Group C (84 patients in whom the embolization was not performed). Patients in Group A were found to be associated with the shortest length of both periods (P < 0.05).Lower PAI values were related to a prolonged pleural drainage duration and postoperative hospital stay. APC coil embolizations may reduce the risk if they are performed shortly (less than 30 days) before the operation.

Late recovery of the cardiopulmonary exercise capacity after transcatheter amplatzer device closures for atrial septal defects in adults.

Transcatheter atrial septal defect (ASD) closures using an Amplatzer Septal Occluder (ASO) have been widely performed. Compared to children, we sometimes experience late recovery of exercise performance in adult patients. Our study aimed to evaluate the change in the cardiopulmonary exercise capacity in asymptomatic or mildly symptomatic adult patients after a transcatheter ASD closure using an ASO. The subjects consisted of 29 patients (age 39.5 ± 13.6 years) that underwent cardiopulmonary exercise testing (CPX) before, 3, 6, and 12 months after a transcatheter secundum ASD closure using an ASO. The peak oxygen consumption (peak VO2), anaerobic threshold (AT), and slope of the correlation between the ventilation and carbon dioxide production (VE/VCO2 slope) were evaluated. We also evaluated the left-ventricular end-diastolic diameter (LVEDD), right-ventricular end-diastolic dimension (RVEDD) by echocardiography, and hemodynamic values by cardiac catheterization before the ASO procedure. The peak VO2 did not show any improvement 3 months after the ASO procedure; however, a significant improvement was displayed 6 and 12 months (baseline: 23.4 ± 6.3, 3 months: 23.6 ± 6.4, 6 months: 25.1 ± 5.6, 12 months: 26.4 ± 5.3 mL/kg/min; p < 0.001) after the ASO. The LVEDD (before: 38.1 ± 3.6, 3 months: 43.4 ± 3.4 mm; p < 0.001) and RVEDD (before: 33.6 ± 5.3, 3 months: 26.3 ± 2.6 mm; p < 0.001) on echocardiography quickly improved 3 months after the ASO. Although the LVEDD and RVEDD normalized 3 months after the ASO, the peak VO2 still decreased; however, the peak VO2 improved to almost a normal range 6 months after the ASO.

Efficacy and safety of tolvaptan after pediatric congenital heart disease surgery.

It is not clear whether tolvaptan is safe and effective irrespective of various underlying clinical conditions including the functional ventricle morphology, chromosomal abnormalities, and renal function after complex pediatric congenital heart disease surgery. Also, the appropriate dose of tolvaptan in these patients has not been previously identified. We retrospectively assessed the urine volume, body weight, patient clinical characteristics, laboratory data, and vital signs before and on days 1 and 7 of the tolvaptan administration after congenital heart disease surgery. Also, we assessed the relationship between the tolvaptan dose and its effects. A total of 86 patients were included the study. The mean time from the surgery to the tolvaptan administration was 23.5 ± 3.7 days. After administering tolvaptan, the urine volume significantly increased and body weight significantly decreased from baseline by days 1 and 7 (p < 0.0001). The urine volume significantly increased more in the survivors than the deceased. Of the 22 patients who had low serum sodium concentrations at baseline, 20 had an increased serum sodium concentration on day 7. The clinical effect of tolvaptan was not affected by the functional ventricle morphology, chromosomal abnormalities, or renal function. There was a positive correlation between the tolvaptan dose and change in the urine volume until a tolvaptan dose of up to 0.3 mg/kg/day but not at more than 0.3 mg/kg/day. Tolvaptan administration is safe and effective after congenital heart disease surgery irrespective of various underlying clinical conditions. Though the urine volume tends to increase until a tolvaptan dose of up to 0.3 mg/kg/day in pediatric congenital heart disease patients, there was no further benefit with more than 0.3 mg/kg/day.

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.

Early assessment of cardiac troponin I predicts the postoperative cardiac status and clinical course after congenital heart disease surgery.

Cardiac troponin I (cTnI) is a regulatory protein with a high sensitivity and specificity for cardiac injury. Preoperative and postoperative elevations of cTnI are usually considered predictors of the mortality and morbidity. However, little is known about the relationship between the cTnI and postoperative course after the congenital heart disease (CHD) operation. Sixty-five consecutive patients who underwent cardiac surgery for CHD at our institution between March 2016 and January 2017 were included. The cTnI was measured after the operation. Also, the association between the cTnI and duration of the catecholamine use, ICU stay, aortic cross clamp time, and other clinical parameters were assessed. The cTnI level on postoperative day 1 was positively correlated with the duration of the catecholamine use (p < 0.001) and ICU stay (p < 0.001). Also, a higher cTnI level was associated with a lower urine volume and higher lactate level 24 h after the ICU admission. In the multivariable regression analysis, the cTnI was a significant independent predictor of the catecholamine use (p = 0.002) and ICU stay (p = 0.003). The cTnI level on postoperative day 1 was a predictor of the duration of the catecholamine use and ICU stay.

Predictors of Early Postoperative Supraventricular Tachyarrhythmias in Children After the Fontan Procedure.

Postoperative arrhythmias are a frequent and fatal complication after the Fontan operation. However, clinical evidence demonstrating early postoperative arrhythmias in children undergoing the Fontan operation is limited. This study aimed to evaluate the prevalence of arrhythmias and identify the predictors of early postoperative supraventricular tachyarrhythmias (SVTs) after the Fontan procedure.Data were analyzed from 80 pediatric patients who underwent Fontan procedures between April 2000 and December 2017 in a single-center retrospective study. Early postoperative SVTs were defined as arrhythmias within 30 days after the Fontan procedure. We divided the patients into two groups, with or without early postoperative arrhythmias, and the predictors of early postoperative arrhythmias were analyzed. A multivariate logistic regression analysis was performed to determine independent predictors of early postoperative SVTs after the Fontan procedure.Early postoperative SVTs were observed in 21 patients (26.3%). The most common arrhythmia was junctional ectopic tachycardia. After an adjustment, an atrioventricular valve regurgitation (AVVR) grade of ≥2 (odds ratio 10.54, 95% confidence interval 2.52 to 44.17, P = 0.001) and preoperative arrhythmias (odds ratio 26.49, 95% confidence interval 1.64 to 428.62, P = 0.021) were significant predictors of early postoperative SVTs after the Fontan operation.An AVVR grade ≥2 and preoperative arrhythmia were significant predictors associated with early postoperative SVTs. Intervention for AVVR may provide clinical benefit for preventing early postoperative arrhythmias after the Fontan operation.

Usefulness of Red Blood Cell Distribution Width in the Assessment of Hemodynamics After Tetralogy of Fallot Repair.

BACKGROUND: There are no reports on the effect of red blood cell distribution width (RDW) in surgical repair of tetralogy of Fallot (ToF). Methods and Results: A total of 50 patients who underwent cardiac catheterization after surgical repair of ToF were retrospectively assessed. RDW was positively correlated with the ratio of right ventricular pressure to left ventricular pressure (RVP/LVP; P<0.0001, r2=0.57). Patients with elevated RDW had a higher RVP/LVP than those with a normal RDW (P<0.0001). Also, elevated RDW was related to elevated central venous pressure (P<0.0001), decreased mixed venous oxygen saturation (P<0.0001), greater pulmonary stenosis (P=0.003) and severe pulmonary regurgitation on echocardiography (P<0.0001), a higher rate of residual ventricular septal defect leak (P=0.004) and higher reoperation rate (P=0.009). Of the 7 patients who underwent reoperation, 6 had decrease in RDW after reoperation (P=0.012). On multivariable regression analysis, RDW was the strongest indicator of higher RVP/LVP. CONCLUSIONS: For the first time, RDW has been shown to be a strong indicator for assessing the hemodynamics and risk of later reoperation after surgical repair of ToF.

Linking the heart and the brain: Neurodevelopmental disorders in patients with catecholaminergic polymorphic ventricular tachycardia.

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an uncommon inherited arrhythmia disorder characterized by adrenergically evoked ventricular arrhythmias. Mutations in the cardiac calcium release channel/ryanodine receptor gene (RYR2) are identified in the majority of patients with CPVT. RyR2 is also the major RyR isoform expressed in the brain. OBJECTIVE: The purpose of this study was to estimate the prevalence of intellectual disability (ID) and other neurodevelopmental disorders (NDDs) in RYR2-associated CPVT (CPVT1) and to study the characteristics of these patients. METHODS: We reviewed the medical records of all CPVT1 patients from 12 international centers and analyzed the characteristics of all CPVT1 patients with concomitant NDDs. We functionally characterized the mutations to assess their response to caffeine activation. We did not correct for potential confounders. RESULTS: Among 421 CPVT1 patients, we identified 34 patients with ID (8%; 95% confidence interval 6%-11%). Median age at diagnosis was 9.3 years (interquartile range 7.0-14.5). Parents for 24 of 34 patients were available for genetic testing, and 13 of 24 (54%) had a de novo mutation. Severity of ID ranged from mild to severe and was accompanied by other NDDs in 9 patients (26%). Functionally, the ID-associated mutations showed a markedly enhanced response of RyR2 to activation by caffeine. Seventeen patients (50%) also had supraventricular arrhythmias. During median follow-up of 8.4 years (interquartile range 1.8-12.4), 15 patients (45%) experienced an arrhythmic event despite adequate therapy. CONCLUSION: Our study indicates that ID is more prevalent among CPVT1 patients (8%) than in the general population (1%-3%). This subgroup of CPVT1 patients reveals a malignant cardiac phenotype with marked supraventricular and ventricular arrhythmias.

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.

Retrosternal Implantation of the Cardioverter-Defibrillator Lead in an Infant.

Using an implantable cardioverter-defibrillator (ICD) in small children is still challenging, but the need is increasing. We present a new approach to overcoming ICD problems caused by growth in infants. A redundant ICD lead was fixed to the superior border of the sternum and tunneled retrosternally to the subxiphoid region for connection to the generator, which was placed in a pocket beneath the left transversus abdominis muscle. The redundant retrosternal part of the lead straightened during growth, while cardiac coverage by the cardioversion energy field and the defibrillation vector were maintained appropriately.

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.

Patient-Specific Human Induced Pluripotent Stem Cell Model Assessed with Electrical Pacing Validates S107 as a Potential Therapeutic Agent for Catecholaminergic Polymorphic Ventricular Tachycardia.

INTRODUCTION: Human induced pluripotent stem cells (hiPSCs) offer a unique opportunity for disease modeling. However, it is not invariably successful to recapitulate the disease phenotype because of the immaturity of hiPSC-derived cardiomyocytes (hiPSC-CMs). The purpose of this study was to establish and analyze iPSC-based model of catecholaminergic polymorphic ventricular tachycardia (CPVT), which is characterized by adrenergically mediated lethal arrhythmias, more precisely using electrical pacing that could promote the development of new pharmacotherapies. METHOD AND RESULTS: We generated hiPSCs from a 37-year-old CPVT patient and differentiated them into cardiomyocytes. Under spontaneous beating conditions, no significant difference was found in the timing irregularity of spontaneous Ca2+ transients between control- and CPVT-hiPSC-CMs. Using Ca2+ imaging at 1 Hz electrical field stimulation, isoproterenol induced an abnormal diastolic Ca2+ increase more frequently in CPVT- than in control-hiPSC-CMs (control 12% vs. CPVT 43%, p<0.05). Action potential recordings of spontaneous beating hiPSC-CMs revealed no significant difference in the frequency of delayed afterdepolarizations (DADs) between control and CPVT cells. After isoproterenol application with pacing at 1 Hz, 87.5% of CPVT-hiPSC-CMs developed DADs, compared to 30% of control-hiPSC-CMs (p<0.05). Pre-incubation with 10 µM S107, which stabilizes the closed state of the ryanodine receptor 2, significantly decreased the percentage of CPVT-hiPSC-CMs presenting DADs to 25% (p<0.05). CONCLUSIONS: We recapitulated the electrophysiological features of CPVT-derived hiPSC-CMs using electrical pacing. The development of DADs in the presence of isoproterenol was significantly suppressed by S107. Our model provides a promising platform to study disease mechanisms and screen drugs.

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.

Biventricular repair of pulmonary atresia with intact ventricular septum and severely hypoplastic right ventricle: a case report of a minimum intervention surgical approach.

BACKGROUND: In patients who have pulmonary atresia with an intact ventricular septum and severe right ventricular hypoplasia, biventricular repair is considered to be impossible and multiple interventions are generally required for definitive repair. CASE PRESENTATION: An initial palliative procedure was performed in a 1-month-old boy to promote right ventricular development by pulmonary valvectomy without disrupting the annulus, and appropriate oxygenation was achieved with a central funnel shunt. The retained annulus caused functional stenosis and prevented unfavorable right ventricular dilatation due to regurgitation. Thirteen years later, without any other intervention, reconstruction of the right ventricular outflow tract was successfully performed for definitive biventricular repair by using a new expanded polytetrafluoroethylene bulging valved conduit with extended longevity. CONCLUSIONS: The successful outcome in this case suggests that our minimal palliation strategy could be one option for management of these patients.

Successful control of life-threatening polymorphic ventricular tachycardia by radiofrequency catheter ablation in an infant.

We present a case of a 9-month-old girl in whom malignant polymorphic ventricular tachycardia (VT) was successfully controlled by radiofrequency catheter ablation under guidance with a three-dimensional mapping system. The VTs originated from the left ventricular lateral wall, left ventricular anterior wall, and left ventricular apex. At least six types of VTs were documented during the electrophysiology study. All VTs were successfully controlled after two sessions of radiofrequency catheter ablation, and she was discharged from our hospital on propranolol, mexiletine, flecainide, and aprindine.

Long-term prognostic impact of dobutamine stress echocardiography in patients with Kawasaki disease and coronary artery lesions: a 15-year follow-up study.

OBJECTIVES: This study sought to determine the prognostic value of dobutamine stress echocardiography (DSE) over a 15-year follow-up for predicting cardiac events in adolescent Kawasaki disease (KD) patients with coronary artery lesions (CALs). BACKGROUND: Although DSE is an established technique for the detection of coronary artery disease, its prognostic value to predict cardiac events in adolescent KD patients with CALs is unknown. METHODS: Fifty-eight adolescent KD patients, including 36 patients with CALs documented by coronary angiography, and 22 patients with normal coronary arteries documented by echocardiography who underwent DSE were reviewed at initial testing (mean age: 13.6 years) and at 15 years' follow-up. Follow-up events were tabulated as major adverse cardiac events (MACEs) that included cardiac death, nonfatal myocardial infarction, and revascularization. RESULTS: During a mean follow-up of 14.7 years, there were 16 patients with MACEs (acute myocardial infarction: n = 1; old myocardial infarction: n = 7; coronary artery bypass grafting: n = 4; percutaneous coronary intervention: n = 4). Significant coronary artery disease (CAD) (>70% coronary stenosis) was detected in 31.0% of patients at initial testing and 42.1% at follow-up. However, there were no significant differences in wall motion score indices (WMSI) at peak DSE between initial testing and follow-up (p = 0.762). Five of 6 patients (85%) with false-positive DSE results (WMSI: ≥1.25) at initial testing, who had giant aneurysms without CAD, developed CAD with MACEs during follow-up. Cumulative event-free survival rate to 15 years was 25.0% in patients with WMSI ≥1.25 and 91.7% in patients with WMSI <1.25. Cox regression analysis showed the grade of peak WMSI at initial testing to be the only independent predictor of MACEs (relative risk: 3.28; 95% confidence interval: 1.73 to 6.20). CONCLUSIONS: DSE provided independent prognostic information up to 15 years in adolescent KD survivors.

Electrocardiographic screening of 1-month-old infants for identifying prolonged QT intervals.

BACKGROUND: Neonatal electrocardiographic screening is used to screen infants with prolonged QT intervals, as previously shown in whites. However, this procedure needs to be confirmed in other ethnic groups. METHODS AND RESULTS: In 8 areas in Japan, an ECG was recorded in 4285 infants at 1-month medical checkup. A prospective study showed that a provisional criterion of QTc≥470 ms was appropriate for infants. To assess the validity of the criterion, all infants with a QTc between 460 and 470 ms were followed up. Five infants had a QTc≥470 ms. Four infants were diagnosed with prolonged QT intervals from follow-up ECGs. Four infants showed no symptoms and did not have a family history of long-QT syndrome. Two infants showed progressive prolongation of QT intervals, and medication was started. Genetic testing was performed in 3 of 4 infants with prolonged QT intervals, and it revealed a KCNH2 mutation (3065 delT, L1021fs+34X) in 1 infant. One infant with a QTc≥470 ms and 2 infants with a QTc between 460 and 470 ms showed a decline in their QTc values during follow-up. The study screened another infant with Wolff-Parkinson-White syndrome who was diagnosed with noncompaction before symptoms appeared. CONCLUSIONS: Neonatal electrocardiographic screening can identify infants likely to be affected by long-QT syndrome in the Japanese population, as already shown in whites. This screening may also be useful in identifying other important cardiac diseases.

Characteristics of earlier atherosclerotic involvement in adolescent patients with Kawasaki disease and coronary artery lesions: significance of gray scale median on B-mode ultrasound.

OBJECTIVE: To test the hypothesis that textural changes in the carotid intima-media complex (IMC) detected by B-mode ultrasound are associated with the difference of remodeling process in earlier atherosclerotic involvement in patients with Kawasaki disease (KD) and coronary artery lesions (CALs). METHODS: Eighteen patients with KD and CALs (mean age 17.2 years), 17 patients with heterozygous familial hypercholesterolemia (FH) (mean age 16.9 years) and 15 age-matched healthy controls (Cont) were assessed and compared for carotid intima-media thickness (CIMT), elastic property (E(p)), and first- and second-order statistics. RESULTS: KD showed significantly higher gray scale median (GSM) than FH and Cont. KD and FH showed significantly higher CIMT, entropy and lower angular second moment than Cont, but no significant difference was found between KD and FH. CONCLUSION: Higher GSM in KD may indicate alteration of tissue components and heterogeneity of IMC, suggesting the development of arteriosclerotic vascular remodeling after vasculitis. This is distinct from that of atherosclerosis with lower GSM often observed in FH.