S. Tsao

• Bachelor of Medicine
• Professor (Associate) at The University of Hong Kong

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, inc...

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 le...

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 car...

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 eva...

Background: Apple watch-derived electrocardiogram (awECG) may help identify prolongation of corrected QT (QTc) interval. This study aimed to determine its usefulness for assessment of prolongation of QTc interval in children and adolescents with long QT syndrome (LQTS). Methods: Children and adolescents with and without LQTS were recruited for m...

Preoperative evaluation of a patient with congenital heart disease (CHD) requires an understanding of the anatomy and physiology of the lesion, associated cardiac and systemic anomalies, prior surgeries, and rhythm concerns. This chapter focuses on specific concerns for evaluating patients in each of the age groups, taking into account the alternat...

In this study, we examined the clinical and electrophysiological outcomes of adolescents in Hong Kong who developed myocarditis or pericarditis following BNT162b2 vaccination for COVID-19, and followed-up for 60 to 180 days after their initial diagnosis. Clinical assessments included electrocardiogram (ECG) and echocardiogram at the initial admissi...

Introduction: In adults with congenital heart disease, intra-atrial reentrant tachycardia (IART) is a common arrhythmia that causes significant morbidity and mortality. One treatment option for IART is anti-tachycardia pacing. Atrial anti-tachycardia pacing algorithms deliver therapy for IART with ≥ 2:1 conduction, but most algorithms will not rec...

BACKGROUND: Age-specific incidence of acute myocarditis/pericarditis in adolescents following Comirnaty vaccination in Asia is lacking. This study aimed to study the clinical characteristics and incidence of acute myocarditis/pericarditis among Hong Kong adolescents following Comirnaty vaccination. METHODS: This is a population cohort study in Hong...

Symptoms are the most common indication for ablation in children with atrioventricular nodal reentrant tachycardia (AVNRT). After the procedure, patients may continue to report palpitations. The objective of this study was to quantify the risk and duration of palpitations after pediatric slow pathway modification as well as demographic and technica...

Background: Prior ECG standards in children have largely been defined without echo confirmation of normal anatomy. The Pediatric Heart Network Normal Echocardiogram Z-score Project provides a racially diverse age/sex classified group of healthy children with normal echos that included 2170 matched contemporaneous digitally acquired ECGs. We hypothe...

Background There is an active debate regarding the optimal method of Fontan palliation. In light of this, we reviewed our experience with the non-fenestrated extracardiac Fontan including Fontan conversion. Methods Retrospective review was performed of all non-fenestrated extracardiac Fontan and Fontan conversion operations at our institution from...

https://cslide-us.ctimeetingtech.com/hrs20/attendee/eposter/poster/77?q=D-PO01-135

Children with ventricular pre-excitation are at risk for sudden death. This retrospective pediatric study identified patients > 8 years of age who had undergone electrophysiology study (EPS). Our primary objective was to determine the performance characteristics of non-invasive risk stratification. Subjects were separated into two groups. Group 1 w...

A pregnant woman with KCNQ1 variant long QT syndrome (LQTS) underwent fetal magnetocardiography (fMCG) after atrioventricular (AV) block was noted during fetal echocardiogram ‐ atypical for LQTS type 1. Concern for fetal LQTS on fMCG prompted monitoring of maternal labs, change of maternal beta blocker therapy, and frequent fetal echocardiograms. C...

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 h...

Background: Since the onset of pediatric catheter ablation, the pediatric electrophysiology community has reported outcomes via various registries (PAPCA and the Pediatric Catheter Ablation registry (PCAR)). Most recently, a modern era pediatric and congenital ablation registry (MAP-IT) was developed for eventual incorporation into the NCDR IMPACT...

Background: Interpretation of pediatric ECGs is limited by lack of accurate sex- and race-specific normal reference values obtained with modern technology for all ages. We sought to obtain contemporary digital ECG measurements in healthy children from North America, to evaluate the effects of sex and race, and to compare our results to commonly us...

Isolated premature atrial contractions (PACs) and premature ventricular contractions (PVCs) are noted in up to 15% of newborns, predominantly as supraventricular beats. Infants with isolated PACs or PVCs are usually asymptomatic. Atrial ectopy may present as premature complexes, and can be confused with sinus bradycardia or ventricular ectopy. Freq...

Objective: Twenty-four hour ambulatory electrocardiograms (“Holter” monitors) are a key diagnostic test in cardiology. Commercial electronic medical record (EMR) tools have not been designed for pediatric Holter monitor reporting and paper-based methods are inefficient. Methods: Our tertiary pediatric hospital adapted a radiology EMR tool to a card...

Introduction: Fontan conversion surgery has extended survival for patients with univentricular heart, yet raised concerns regarding durability of hepatic function. Methods: We reviewed liver outcomes among transplant-free survivors of Fontan conversion with arrhythmia surgery at our institution. Hepatic screening included a combination of annual li...

Background: Atrial arrhythmias and progressive circulatory failure frequently develop in patients with a Fontan circulation. Improvement of flow dynamics and revision of the arrhythmia substrate may improve outcomes in selected patients. We sought to determine intermediate-term outcomes after Fontan conversion with arrhythmia operations and identi...

Introduction: Long-term growth outcomes and the prevalence of obesity among older single ventricle (SV) patients have not been well characterized. We investigated these parameters, as well as the impact of obesity on survival, in an older cohort of SV patients presenting for Fontan conversion. Methods: We analyzed preoperative height, weight, an...

Specific congenital heart anomalies significantly increase the risk for late atrial arrhythmias, raising the question whether prophylactic arrhythmia operations should be incorporated into reparative open heart procedures. Currently no consensus exists regarding standard prophylactic arrhythmia procedures. Questions remain concerning the arrhythmia...

Introduction: The negative cardiovascular effects of obesity are well described in adult patients. By increasing both pulmonary and systemic vascular resistance, we hypothesized that obesity would be particularly deleterious in the setting of single ventricle physiology. Our aim was to assess the impact of obesity on mid-term survival in patients f...

The study objective was to determine whether the extracardiac conduit Fontan confers an arrhythmia advantage over the intracardiac lateral tunnel Fontan. This multicenter study of 1271 patients compared bradyarrhythmia (defined as need for pacing) and tachyarrhythmia (defined as needing antiarrhythmic therapy) between 602 patients undergoing the in...

Multicenter clinical registries are increasingly recognized as valuable tools for establishing benchmarks, facilitating patient-centered quality improvement and research. In 2010, the Pediatric and Congenital Electrophysiology Society convened a taskforce of its members to design, construct, and implement a clinical registry known as the Multicente...

The term "ventricular preexcitation" or "preexcitation" refers to the presence of a delta wave and short PR interval on electrocardiogram (ECG) during normal sinus rhythm. The Wolff-Parkinson-White (WPW) syndrome refers to preexcitation during sinus rhythm, in association with episodes of supraventricular tachycardia (SVT). The delta wave represent...

Background: We evaluated the effects of the site of ventricular pacing on left ventricular (LV) synchrony and function in children requiring permanent pacing. Methods and results: One hundred seventy-eight children (aged <18 years) from 21 centers with atrioventricular block and a structurally normal heart undergoing permanent pacing were studie...

Background: Arrhythmias, both brady and tachyarrhythmias, are common after the Fontan operation for single ventricle. By avoiding surgery near the sinus node, reducing pressure overload of the right atrium (RA), and decreasing RA scarring, the extracardiac conduit (ECC) is thought to be less arrhythmogenic than the intracardiac lateral tunnel (ILT)...

Cardiopulmonary resuscitation (CPR) has been a mainstay of immediate response to acute cardiorespiratory failure since it was first introduced by Kouwenhoven et al. in 1960. The goal of CPR is to maximize coronary and cerebral blood flow and to restore spontaneous circulation. To these ends, the principles are largely unchanged from earlier descrip...

This article was prepared to summarize the points made in a debate that the first author (C.L.B.) had with Dr. Richard Jonas at the American Association for Thoracic Surgery 90th Annual Meeting. The topic of the debate was the optimal surgical approach for functional single-ventricle patients: extracardiac versus intra-atrial lateral tunnel Fontan....

Background: Exercise tolerance in Fontan patients is known to decline with advancing age. The impact of improving right atrial flow dynamics and eliminating anti-arrhythmic medications on exercise tolerance is not known. Hypothesis: Successful Fontan conversion with arrhythmia surgery results in improvement in exercise tolerance over time. Methods:...

Background: Congenital Central Hypoventilation Syndrome (CCHS) is a rare disorder characterized by alveolar hypoventilation, autonomic dysregulation, and risk for prolonged sinus pause based on type of Paired-like Homeobox 2B ( PHOX2B ) mutation. Standard of care includes annual 72-hr Holter surveillance. Utility of implanted cardiac pacemakers (PM...

Chronic right ventricular (RV) pacing is associated with deleterious effects on cardiac function. In an observational multicentre study in children with isolated atrioventricular (AV) block receiving chronic ventricular pacing, the importance of the ventricular pacing site on left ventricular (LV) function was investigated. Demographics, maternal a...

The atrioventricular (AV) node is permanently damaged in approximately 3% of congenital heart surgery operations, requiring implantation of a permanent pacemaker. Improvements in pacemaker design and in alternative treatment modalities require an effective in vivo model of complete heart block (CHB) before testing can be performed in humans. Such a...

We assessed our pacemaker strategy, use of antitachycardia therapies, generator longevity, and need for programming changes in patients having Fontan conversion with arrhythmia surgery. Between 1994 and 2008, of 121 consecutive patients having Fontan conversion and arrhythmia surgeries, 120 patients underwent pacemaker implantation at the time of F...

Arrhythmia surgery has favorably impacted the clinical course of debilitating atrial and ventricular arrhythmias in patients with and without congenital heart disease. This study reviews arrhythmia mechanisms and documents long-term outcome of patients undergoing arrhythmia operations alone or associated with congenital heart repairs. The analysis...

As of September 2007, 120 patients have undergone a Fontan conversion procedure at Children's Memorial Hospital (Chicago, IL). One of the primary indications for surgery in these patients has been arrhythmias, either atrial reentry tachycardia or atrial fibrillation. The surgical treatment of those two lesions has been with the modified right atria...

Background The evolving operative strategy and course of 111 consecutive Fontan conversions with arrhythmia surgery and pacemaker therapy were reviewed to identify risk factors for poor outcome. Methods Since 1994, 111 patients (mean age 22.5 ± 7.9 years) underwent Fontan conversion with arrhythmia surgery. The series was divided into three time p...

This review evaluates the outcome of a treatment strategy using dual-chamber pacemakers for neonates with congenital heart block. From 1989 to 2006, 10 neonates had dual-chamber epicardial pacemaker placement for congenital heart block. Mean age and weight were 4.4 +/- 5.6 days and 2.8 +/- 0.6 kg. Four patients had heterotaxy syndrome and required...

The evolving operative strategy and course of 111 consecutive Fontan conversions with arrhythmia surgery and pacemaker therapy were reviewed to identify risk factors for poor outcome. Since 1994, 111 patients (mean age 22.5 +/- 7.9 years) underwent Fontan conversion with arrhythmia surgery. The series was divided into three time periods: (1) 1994 t...

The principles of Fontan conversion with arrhythmia surgery are to restore the cardiac anatomy by converting the original atriopulmonary connection to a total cavopulmonary artery extracardiac connection and treat the underlying atrial arrhythmias. Successful outcomes of this procedure are dependent on a thorough understanding of several factors: t...

In this study, we determine whether the presence of enzyme-linked immunosorbent assay (ELISA) detected anti-human leukocyte antigen (HLA) antibodies correlates with acute and chronic rejection in pediatric heart transplantation (Tx). Forty-five patients, who had serial ELISA pre- and posttransplantation, were studied. Age at Tx was 8.2 +/- 7.2 year...

Unlabelled: The presence of recurrent respiratory symptoms and right heart enlargement in an ex-premature infant is suggestive of chronic lung disease. Pulmonary vein stenosis is a rare, progressive disorder that produces similar symptoms and signs. A case is reported in which pulmonary vein stenosis was revealed by Doppler echocardiography, and t...

The presence of recurrent respiratory symptoms and right heart enlargement in an ex-premature infant is suggestive of chronic lung disease. Pulmonary vein stenosis is a rare, progressive disorder that produces similar symptoms and signs. A case is reported in which pulmonary vein stenosis was revealed by Doppler echocardiography, and this applicati...