Noninvasive assessment of hydroquinidine effect in Brugada syndrome (QUIET BrS).

Background: Hydroquinidine reduces arrhythmic events in patients with Brugada syndrome (BrS). The mechanism by which it exerts antiarrhythmic benefit and its electrophysiological effects on BrS substrate remain incompletely understood.

Objective: This study aimed to determine the effect of hydroquinidine on ventricular depolarization and repolarization in patients with BrS in vivo.

2023 Cardiac Society of Australia and New Zealand Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation.

Catheter ablation for atrial fibrillation (AF) has increased exponentially in many developed countries, including Australia and New Zealand. This Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation from the Cardiac Society of Australia and New Zealand (CSANZ) recognises healthcare factors, expertise and expenditure relevant to the Australian and New Zealand healthcare environments including considerations of potential implications for First Nations Peoples. The statement is cognisant of international advice but tailored to local conditions and populations, and is intended to be used by electrophysiologists, cardiologists and general physicians across all disciplines caring for patients with AF.

Predicting Adverse Outcomes Following Catheter Ablation Treatment for Atrial Flutter/Fibrillation.

Background & Aim: To develop prognostic survival models for predicting adverse outcomes after catheter ablation treatment for non-valvular atrial fibrillation (AF) and/or atrial flutter (AFL).

Methods: We used a linked dataset including hospital administrative data, prescription medicine claims, emergency department presentations, and death registrations of patients in New South Wales, Australia. The cohort included patients who received catheter ablation for AF and/or AFL.

Clinical Management of Brugada Syndrome: Commentary From the Experts.

Although there is consensus on the management of patients with Brugada Syndrome with high risk for sudden cardiac arrest, asymptomatic or intermediate-risk patients present clinical management challenges. This document explores the management opinions of experts throughout the world for patients with Brugada Syndrome who do not fit guideline recommendations. Four real-world clinical scenarios were presented with commentary from small expert groups for each case.

Provocation testing in congenital long QT syndrome: A practical guide.

Congenital long QT syndrome (LQTS) is a hereditary cardiac channelopathy with an estimated prevalence of 1 in 2500. A prolonged resting QT interval corrected for heart rate (QTc interval) remains a key diagnostic component; however, the QTc value may be normal in up to 40% of patients with genotype-positive LQTS and borderline in a further 30%. Provocation of QTc prolongation and T-wave changes may be pivotal to unmasking the diagnosis and useful in predicting genotype.

The New South Wales Sudden Cardiac Arrest Registry: A Data Linkage Cohort Study.

Background: Sudden cardiac arrest (SCA) in young people aged 1 to 50 years often occurs with no presenting symptoms or risk factors prompting screening for cardiovascular disease prior to their cardiac arrest. Approximately 3,000 young Australians suffer from sudden cardiac death (SCD) each year, making this a major public health issue. However, there is significant variation in the way incidence is estimated resulting in discrepancy across reporting which impacts our ability to understand and prevent these devastating events.

Prognostic benefit of catheter ablation of atrial fibrillation in heart failure: An updated meta-analysis of randomized controlled trials.

Background: The prognostic role of catheter ablation of atrial fibrillation (AF) in patients with heart failure (HF) remains uncertain, with guideline recommendations largely based on a single trial. We conducted a meta-analysis of randomized controlled trials (RCTs) assessing the prognostic impact of AF ablation in patients with HF.

Methods: Electronic databases were searched for RCTs comparing 'AF ablation' versus 'other care' (medical therapy and/or atrioventricular node ablation with pacing) in patients with HF.

Longitudinal assessment of structural phenotype in Brugada syndrome using cardiac magnetic resonance imaging.

Background: Despite historically being considered a channelopathy, subtle structural changes have been reported in Brugada syndrome (BrS) on histopathology and cardiac magnetic resonance (CMR) imaging. It is not known if these structural changes progress over time.

Objective: The study sought to assess if structural changes in BrS evolve over time with serial CMR assessment and to investigate the utility of parametric mapping techniques to identify diffuse fibrosis in BrS.

The role of genetic testing in diagnosis and care of inherited cardiac conditions in a specialised multidisciplinary clinic.

Background: The diagnostic yield of genetic testing for inherited cardiac diseases is up to 40% and is primarily indicated for screening of at-risk relatives. Here, we evaluate the role of genomics in diagnosis and management among consecutive individuals attending a specialised clinic and identify those with the highest likelihood of having a monogenic disease.

Methods: A retrospective audit of 1697 consecutive, unrelated probands referred to a specialised, multidisciplinary clinic between 2002 and 2020 was performed.

Novel Epicardial Access Technique Facilitated by Carbon Dioxide Insufflation of the Pericardium for Ablation of Ventricular Arrhythmias: Lessons From the Early Experience From a Single Centre in Australia.

Introduction: Epicardial access for mapping and ablation of the epicardial substrate may be required in catheter ablation of ventricular tachycardias (VT). However, high complication rates are associated with the standard epicardial access approach. Recently, a novel method of intentional coronary vein (CV) exit with pericardial CO insufflation to facilitate epicardial access has been described.

Concealed Cardiomyopathy in Autopsy-Inconclusive Cases of Sudden Cardiac Death and Implications for Families.

Background: Genetic testing following sudden cardiac death (SCD) is currently guided by autopsy findings, despite the inherent challenges of autopsy examination and mounting evidence that malignant arrhythmia may occur before structural changes in inherited cardiomyopathy, so-called "concealed cardiomyopathy" (CCM).

Objectives: The authors sought to identify the spectrum of genes implicated in autopsy-inconclusive SCD and describe the impact of identifying CCM on the ongoing care of SCD families.

Methods: Using a standardized framework for adjudication, autopsy-inconclusive SCD cases were identified as having a structurally normal heart or subdiagnostic findings of uncertain significance on autopsy.

An Observational Study of Clinical and Health System Factors Associated With Catheter Ablation and Early Ablation Treatment for Atrial Fibrillation in Australia.

Objective: To investigate clinical and health system factors associated with receiving catheter ablation (CA) and earlier ablation for non-valvular atrial fibrillation (AF).

Methods: We used hospital administrative data linked with death registrations in New South Wales, Australia for patients with a primary diagnosis of AF between 2009 and 2017. Outcome measures included receipt of CA versus not receiving CA during follow-up (using Cox regression) and receipt of early ablation (using logistic regression).

Congenital Long QT Syndrome.

Congenital long QT syndrome (LQTS) encompasses a group of heritable conditions that are associated with cardiac repolarization dysfunction. Since its initial description in 1957, our understanding of LQTS has increased dramatically. The prevalence of LQTS is estimated to be ∼1:2,000, with a slight female predominance.

Systematic review of electrophysiology procedures in patients with obstruction of the inferior vena cava.

Aims: The objective of the study was to conduct a systematic review to describe and compare the different approaches for performing cardiac electrophysiology (EP) procedures in patients with interrupted inferior vena cava (IVC) or equivalent entities causing IVC obstruction.

Methods: We conducted a structured search to identify manuscripts reporting EP procedures with interrupted IVC or IVC obstruction of any aetiology published up until August 2020. No restrictions were applied in the search strategy.

A unique case report of relapsing eosinophilic myocarditis causing atrial myopathy and persistent sinus arrest.

Background: Eosinophilic myocarditis (EM) is a rare and devastating condition. The underlying cause of EM is unknown, and the natural history is not well understood.

Case Summary: A 20-year-old male presented in cardiogenic shock with preceding 24-h history of pleuritic chest pain associated with nausea and vomiting.

Electrocardiographic QRS duration is influenced by body mass index and sex.

Background: Electrocardiogram (ECG) measured QRS duration has been shown to influence cardiovascular outcomes. However, there is paucity of data on whether ECG QRS duration is influenced by obesity and sex in large populations.

Methods: All ECGs performed by a pathology provider over a 2-year period were included.

Management of Congenital Long-QT Syndrome: Commentary From the Experts.

While published guidelines are useful in the care of patients with long-QT syndrome, it can be difficult to decide how to apply the guidelines to individual patients, particularly those with intermediate risk. We explored the diversity of opinion among 24 clinicians with expertise in long-QT syndrome. Experts from various regions and institutions were presented with 4 challenging clinical scenarios and asked to provide commentary emphasizing why they would make their treatment recommendations.

Long-Term Follow-Up of Mortality and Heart Failure Hospitalisation in Patients With Intracardiac Device-Related Tricuspid Regurgitation.

Introduction: Tricuspid regurgitation (TR) is a known complication of cardiac implantable electronic devices (CIED). A better understanding of the patient population affected by this complication and their outcomes is needed. The aims of our study were to: 1) describe the incidence of CIED-related tricuspid regurgitation; 2) identify patient characteristics conferring risk; 3) assess the long-term risk of hospitalisation for heart failure and mortality in patients with this complication.

Genetic architecture of left ventricular noncompaction in adults.

The genetic etiology and heritability of left ventricular noncompaction (LVNC) in adults is unclear. This study sought to assess the value of genetic testing in adults with LVNC. Adults diagnosed with LVNC while undergoing screening in the context of a family history of cardiomyopathy were excluded.

Temporal Variability in Electrocardiographic Indices in Subjects With Brugada Patterns.

Introduction: Patients with Brugada electrocardiographic (ECG) patterns have differing levels of arrhythmic risk. We hypothesized that temporal variations in certain ECG markers may provide additional value for risk stratification. The present study evaluated the relationship between temporal variability of ECG markers and arrhythmic outcomes in patients with a Brugada pattern ECG.

"Concealed cardiomyopathy" as a cause of previously unexplained sudden cardiac arrest.

Background: Genetic heart disease is a common cause of sudden cardiac arrest (SCA) in the young and those without an ischaemic precipitant. Identifying a cause of SCA in these patients allows for targeted care and family screening. Current guidelines recommend limited, phenotype-guided genetic testing in SCA survivors where a specific genetic condition is suspected and genetic testing is not recommended in clinically-idiopathic SCA survivors.