Novel Calmodulin Variant p.E46K Associated With Severe Catecholaminergic Polymorphic Ventricular Tachycardia Produces Robust Arrhythmogenicity in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

Background: CaM (calmodulin) is a ubiquitously expressed, multifunctional Ca sensor protein that regulates numerous proteins. Recently, CaM missense variants have been identified in patients with malignant inherited arrhythmias, such as long QT syndrome and catecholaminergic polymorphic ventricular tachycardia (CPVT). However, the exact mechanism of CaM-related CPVT in human cardiomyocytes remains unclear.

Non-missense variants of KCNH2 show better outcomes in type 2 long QT syndrome.

Aims: More than one-third of type 2 long QT syndrome (LQT2) patients carry KCNH2 non-missense variants that can result in haploinsufficiency (HI), leading to mechanistic loss-of-function. However, their clinical phenotypes have not been fully investigated. The remaining two-thirds of patients harbour missense variants, and past studies uncovered that most of these variants cause trafficking deficiency, resulting in different functional changes: either HI or dominant-negative (DN) effects.

Efficacy of SubcutAneous implantable cardioVErter-defibrillators in ≤18 year-old CHILDREN: SAVE-CHILDREN registry.

Background: In adult patients, subcutaneous implantable cardioverter defibrillators (S-ICDs) have been reported to be non-inferior to transvenous ICDs with respect to the incidence of device-related complications and inappropriate shocks. Only a few reports have investigated the efficacy of S-ICDs in the pediatric field. This study aimed to investigate the utility and safety of S-ICDs in patients ≤18 years old.

Characteristics of Breath Sounds During Methacholine-induced Bronchoconstriction in Children with Asthma.

Objective: The utility of an analysis of breath sounds as a non-invasive lung function test in children and adults has been studied. Analyzing specific breath sounds during methacholine inhalation challenge is useful for evaluating airway constriction in asthmatic patients.

Patients And Methods: The study population included 57 children with atopic asthma (male: female = 38: 19; median age, 10 years [range, 5-16 years]).

Disrupted Ca1.2 selectivity causes overlapping long QT and Brugada syndrome phenotypes in the CACNA1C-E1115K iPS cell model.

Background: A missense mutation in the α1c subunit of voltage-gated L-type Ca channel-coding CACNA1C-E1115K, located in the Ca selectivity site, causes a variety of arrhythmogenic phenotypes.

Objective: We aimed to investigate the electrophysiological features and pathophysiological mechanisms of CACNA1C-E1115K in patient-specific induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs).

Methods: We generated iPSCs from a patient carrying heterozygous CACNA1C-E1115K with overlapping phenotypes of long QT syndrome, Brugada syndrome, and mild cardiac dysfunction.

Association Between Deleterious SCN5A Variants and Ventricular Septal Defect in Young Patients With Brugada Syndrome.

Objectives: This study aimed to investigate the clinical characteristics of young patients with Brugada syndrome (BrS) with ventricular septal defect (VSD) and explore their genetic backgrounds.

Background: VSD is the most frequently occurring congenital heart disease among children. In contrast, BrS is a rare hereditary disease that is responsible for ventricular fibrillation and sudden cardiac death.

Lung sound analysis in infants with risk factors for asthma development.

Background And Objectives: Using a lung sound analysis, the prognosis of asthma was investigated in infants with risk factors for asthma development by a long-term observation.

Methods: A total of 268 infants were included (median age: 8 months old). The lung sound parameters (the ratio of the third and fourth area to the total area under the curve [A/A and B/A], and the ratio of power and frequency at 50% and 75% of the highest frequency [RPF and RPF]) were evaluated at the first visit.

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.

New Technique to Analyze the Breath Sound Spectrum in Children with Asthma.

Objective: Breath sound parameters have been reported as useful biomarkers for evaluating the airway condition.

Methods: The reliability of breath sound analysis using an improved method was investigated. Eighty-three asthmatic children were included in the present study.

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.

[EFFECT OF INSPIRATORY FLOW ON BREATH SOUND ANALYSIS IN CHILDREN WITH ASTHMA].

Background: In order to determine the optimal breathing method for childhood lung sound analyses, it is important to study the effect of airflow on the parameters of lung sounds.

Methods: Sixty-one well-controlled children with atopic asthma (median; 12 years) participated. After confirming that there was no wheezing or respiratory symptoms, the lung sound spectrums of the inspiratory flow before and after inhalation of a β stimulant were analyzed.

Changes in the Breath Sound Spectrum with Bronchodilator Inhalation in Asthmatic Children with Long-term Management.

Objective: Using a commercially available breath sound analyzer, the airway reversibility in asthmatic children during healthy periods was investigated.

Methods: Fifty samples of 34 children with asthma (median age, 11 years; range, 6-16 years) who visited our hospital and whose lung function was normal were included. The breath sound parameters, the frequency limiting 99% of the power spectrum (F) and spectrum curve indices, the total area under the curve of the dBm data (A/A and B/A) and the ratio of power and frequency at 50% and 75% of the highest frequency of the power spectrum (RPF and RPF) were evaluated before and after β agonist inhalation.

Successful Ablation of Atrial Tachycardia Originating from Inside the Single Atrium and Conduit After a Fontan Operation.

An 18-year-old male who had a past medical history of an intracardiac total cavopulmonary connection (TCPC) operation was referred to our hospital for radiofrequency catheter ablation (RFCA) of supraventricular tachycardia (SVT). Two types of SVTs were induced, and 3-dimensional (3D) maps were created using an ultra-high-density 3-dimensional mapping system (Rhythmia). The earliest atrial activation site (EAAS) of SVT1 was at the superior part of the conduit, and the EAAS of SVT2 was at the inferior part of the single atrium (SA).

Cardiopulmonary failure as a result of brainstem encephalitis caused by enterovirus D68.

Enterovirus D68 (EV-D68) causes respiratory illnesses such as pneumonia, and has been reported to cause acute flaccid myelitis. Enterovirus A71 (EV-A71) is known to cause cardiopulmonary failure due to brainstem encephalitis, but there have been few reports of these conditions being associated with EV-D68. Outbreaks of EV-D68 infection have occurred in the USA, Canada, Europe and Asia.

Anomalous origin of the coronary artery coursing between the great vessels presenting with a cardiovascular event (J-CONOMALY Registry).

Aims: Anomalous origin of the coronary artery (AOCA) with an inter-arterial course (IAC) between the great vessels poses a risk for a life-threatening cardiovascular event. We assessed, in a registry-based study, the clinical features, treatment strategies, and prognoses of life-threatening cardiovascular events ensuant to AOCA.

Methods And Results: Included were 65 AOCA patients (48 men/17 women, aged 41 ± 23 years) from 40 clinical centres who had experienced sudden cardiac arrest (SCA) (n = 30), acute myocardial infarction (AMI) (n = 5), angina (n = 23), or syncope (n = 7).

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.

The necessity of implantable cardioverter defibrillators in patients with Kearns-Sayre syndrome - systematic review of the articles.

The most common cardiac feature of Kearns-Sayre syndrome (KSS) is atrioventricular block (AVB), and pacemaker implantations (PMIs) are recommended for KSS patients with advanced AVB. However, some KSS patients develop fatal arrhythmias such as polymorphic ventricular tachycardia (PMVT) and ventricular fibrillation (VF) and die suddenly even after PMIs. We report a patient with KSS who developed PMVT, VF, and QT prolongation, and was treated with mexiletine and successfully managed with an implantable cardioverter defibrillator (ICD).

Safety and accuracy of the Rhythmia mapping system in pediatric patients.

Background: A new mapping system (Rhythmia) using a 64 mini-electrode small basket array (Orion) was developed that enables rapid high-density mapping in a short time. However, there are few reports about the usefulness of this system in pediatric cases.

Objective: The purpose of this study was to investigate the safety and accuracy of the Rhythmia system and Orion catheter in children.

Efficacy of catheter interventions in the early and very early postoperative period after CHD operation.

Background: Catheter interventions for residual lesions in the early postoperative period after CHD operations are still not established as a reliable treatment option.

Methods: We retrospectively reviewed our institutional experience of cardiac catheterisations and catheter interventions performed in the early postoperative period. We classified our patients into two groups.