Publications by authors named "Sit Yee Kwok"

Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare inherited arrhythmia disorder characterized by ventricular arrhythmia triggered by adrenergic stimulation.

Case Presentation: A 9-year-old boy presented with convulsions following physical exertion. Bidirectional ventricular tachycardia (VT) during a treadmill test led to the diagnosis of catecholaminergic polymorphic ventricular tachycardia (CPVT).

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Background: Brugada syndrome (BrS) is an inherited channelopathy characterized by right precordial ST-segment elevation. This study investigates the clinical and genetic characteristics of children with BrS in Hong Kong.

Methods: A retrospective review was conducted at the only tertiary pediatric cardiology center in Hong Kong from 2002 to 2022, including all pediatric BrS patients under 18 years old.

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Inherited cardiovascular conditions are significant causes of sudden cardiac death in the young (SCDY), making their investigation using molecular autopsy and prevention a public health priority. However, the molecular autopsy data in Chinese population is lacking. The 5-year result (2017-2021) of molecular autopsy services provided for victims of SCDY (age 1-40 years) was reviewed.

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Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT) may cause sudden cardiac death (SCD) despite medical therapy. Therefore, implantable cardioverter-defibrillators (ICDs) are commonly advised. However, there is limited data on the outcomes of ICD use in children.

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Background: Precision medicine in paediatric cardiac channelopathy and cardiomyopathy has a rapid advancement over the past years. Compared to conventional gene panel and exome-based testing, whole genome sequencing (WGS) offers additional coverage at the promoter, intronic regions and the mitochondrial genome. However, the data on use of WGS to evaluate the genetic cause of these cardiovascular conditions in children and adolescents are limited.

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Congenital long QT syndrome (LQTS) is an inherited arrhythmia syndrome associated with sudden cardiac death. Accurate interpretation and classification of genetic variants in LQTS patients are crucial for effective management. All patients with LQTS with a positive genetic test over the past 18 years (2002-2020) in our single tertiary pediatric cardiac center were identified.

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Background: In severely affected patients with catecholaminergic polymorphic ventricular tachycardia, beta-blockers are often insufficiently protective. The purpose of this study was to evaluate whether flecainide is associated with a lower incidence of arrhythmic events (AEs) when added to beta-blockers in a large cohort of patients with catecholaminergic polymorphic ventricular tachycardia.

Methods: From 2 international registries, this multicenter case cross-over study included patients with a clinical or genetic diagnosis of catecholaminergic polymorphic ventricular tachycardia in whom flecainide was added to beta-blocker therapy.

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Article Synopsis
  • A study evaluated the effectiveness of Apple watch-derived electrocardiogram (awECG) in measuring the corrected QT (QTc) interval in children and adolescents with long QT syndrome (LQTS).
  • Researchers compared QTc measurements using awECG and standard 12-lead ECG, finding strong correlation and reliability in the readings.
  • Results indicated that specific awECG leads (II and V5) are reliable for accurately detecting prolonged QTc intervals and abnormal T wave morphologies in this patient group.
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Background: Palliation of the single ventricle (SV) circulation is associated with a burden of lifelong complications. Previous studies have identified that the need for a permanent ventricular pacing system (PPM) may be associated with additional adverse long-term outcomes.

Objectives: The goal of this study was to quantify the attributable risk of PPM in patients with SV, and to identify modifiable risk factors.

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Background: Several medication choices are available for acute and prophylactic treatment of refractory supraventricular tachycardia (SVT) in infants. There are almost no controlled trials, and medication choices are not necessarily evidence based. Our objective was to report the effectiveness of management strategies for infant SVT.

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Background: Children with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for sudden death, and a risk stratification tool does not exist.

Objective: The purpose of this study was to determine whether proband status, age at symptom onset, and/or sex are independent predictors of cardiac events.

Methods: A multicenter, ambispective, cohort of pediatric CPVT patients was categorized by sex, proband status, and age at symptom onset (D1: first decade of life [symptom onset <10 years] or D2: second decade of life [symptom onset 10-18 years, inclusive]).

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Objectives: The primary goal of this study was to evaluate the implant experience and midterm results of subcutaneous implantable cardioverter-defibrillators (S-ICDs) in pediatric patients and those with congenital heart disease.

Background: The S-ICD was developed to avoid the lead-related complications associated with transvenous systems. The absence of intravascular or intracardiac components offers potential advantages to pediatric patients and those with congenital heart disease.

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Objectives: Milrinone is an inodilator widely used in the postoperative management of children undergoing cardiac surgery. The literature supporting its inotropic effect is sparse. We sought to study the effect of milrinone on the vasculature and its effects on the ventricular function using wave intensity analysis.

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Background: The use of high-density electroanatomical mapping in the Chinese population for congenital heart disease (CHD) is not well reported.

Methods: Retrospective review of consecutive transcatheter ablation of atrial tachyarrhythmia using high-density mapping for CHD patients (at least moderate complexity) in the only tertiary congenital heart center in the territory from January 2017 to January 2019 was conducted. Orion mapping catheter in Rhythmia system (Boston Scientific) was used to create activation and voltage maps.

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In this article, we problematize the concept of "culture" in genetic counseling. With globalization and increased mobility of both genetic professionals and clients, there is an increased acknowledgement of the impact of "culture" on a counseling process. There is, however, little agreement on what "culture" is.

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There is paucity of long-term data on adult survivors after biventricular repair of pulmonary atresia with intact ventricular septum (PAIVS) and pulmonary stenosis (PS). This study aimed to determine the cardiac and non-cardiac outcomes of adult survivors after biventricular repair of PAIVS and PS. The cardiac, neurodevelopmental and liver problems of 111 adults, 40 with PAIVS and 71 with PS, were reviewed.

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Aims: To clarify the clinical characteristics and outcomes of children with SCN5A-mediated disease and to improve their risk stratification.

Methods And Results: A multicentre, international, retrospective cohort study was conducted in 25 tertiary hospitals in 13 countries between 1990 and 2015. All patients ≤16 years of age diagnosed with a genetically confirmed SCN5A mutation were included in the analysis.

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Objective: In our previous study, the prevalence of childhood masked hypertension was 11%. This study aims to assess the left ventricular mass index of persistent masked hypertension and determine the factors of elevated left ventricular mass index in Hong Kong Chinese adolescents from a community cohort.

Design: Community prospective cohort study, follow-up of a case-control study in community.

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Background: Due to its availability, atenolol is the primary beta-blocker used in Australia for children with long QT syndrome. There is limited data on long-term follow-up of its use.

Methods: A single-tertiary-center, retrospective, observational study investigating all children and adolescents who had genetically proven long QT syndrome type 1 (LQT1) and type 2 (LQT2) was conducted.

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Background: Emerging data suggest impaired biventricular function in adults late after repair of ventricular septal defect (VSD). We assessed and compared right (RV) and left ventricular (LV) mechanics in adolescents and adults after surgical closure of doubly committed subarterial and perimembranous VSDs.

Methods: A total of 75 subjects were studied: 29 patients after subarterial VSD repair (group I), 17 patients after perimembranous VSD repair (group II) and 29 age-matched controls (group III).

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Catecholamine-associated cardiomyopathies caused by neuroblastoma have rarely been reported. We are reporting 2 cases of neuroblastoma associated with hypertension and severe cardiomyopathic changes in different extremes. One case was dilated cardiomyopathy with heart failure, and the other showed echocardiographic features simulating hypertrophic obstructive cardiomyopathy.

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Objective: Resting heart rate (RHR) is increasingly recognised as a prognostic marker for long term cardiovascular outcomes in adults. This study assessed associations of RHR with blood pressure (BP), anthropometry and exercise in a large representative sample of Hong Kong children.

Study Design, Setting And Subjects: A territory-wide growth survey carried out in 2005-2006 included students sampled from each of Hong Kong's 18 districts.

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