How to correct QT interval after cardiac resynchronisation therapy.

Introduction: This study evaluates various formulae used to correct the QT interval in patients with wide QRS complexes to calculate corrected QT (QTc) following Cardiac Resynchronisation Therapy (CRT).

Methods: We included patients with severe heart failure and left bundle branch block, presenting with a QRS duration of at least 120 milliseconds, who underwent successful CRT implantation. Patients were excluded if they had non-lateral left ventricular lead placement, metabolic disorders, atrial fibrillation, atrial tachycardia, or high-degree atrioventricular block prior to implantation.

Arrhythmogenic Mitral Valve Prolapse: Can We Risk Stratify and Prevent Sudden Cardiac Death?

Ventricular arrhythmias associated with mitral valve prolapse (MVP) and the capacity to cause sudden cardiac death (SCD), referred to as 'malignant MVP', are an increasingly recognised, albeit rare, phenomenon. SCD can occur without significant mitral regurgitation, implying an interaction between mechanical derangements affecting the mitral valve apparatus and left ventricle. Risk stratification of these arrhythmias is an important clinical and public health issue to provide precise and targeted management.

Commotio Cordis in Non-Sport-Related Events: A Systematic Review.

Background: Commotio cordis is an increasingly recognized cause of sudden cardiac death. Although commonly linked with athletes, many events occur in non-sport-related settings.

Objectives: The goal of this study was to characterize and compare non-sport-related vs sport-related commotio cordis.

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.

Association of the Timing and Extent of Cardiac Implantable Electronic Device Infections With Mortality.

Importance: Cardiac implantable electronic device (CIED) infection is a potentially devastating complication with an estimated 12-month mortality of 15% to 30%. The association of the extent (localized or systemic) and timing of infection with all-cause mortality has not been established.

Objective: To evaluate the association of the extent and timing of CIED infection with all-cause mortality.

Ventricular fibrillation episodes related to managed ventricular pacing algorithm in a patient with mitral valve prolapse - "Arrhythmic MVP due to MVP".

We report a case of an implant cardiac defibrillator (ICD) patient who an ICD implanted for ventricular fibrillation (VF) related to mitral valve prolapse. He has 2 episodes of VF in his device lives. First episode of VF in year 2016 was initiated after a pause related to the MVP™ algorithm with a critically timed PVC.

Sex Differences and Utility of Treadmill Testing in Long-QT Syndrome.

Background Diagnosis of congenital long-QT syndrome (LQTS) is complicated by phenotypic ambiguity, with a frequent normal-to-borderline resting QT interval. A 3-step algorithm based on exercise response of the corrected QT interval (QTc) was previously developed to diagnose patients with LQTS and predict subtype. This study evaluated the 3-step algorithm in a population that is more representative of the general population with LQTS with milder phenotypes and establishes sex-specific cutoffs beyond the resting QTc.

Atrial Tachyarrhythmias and Stroke: Temporal Relationship and Stroke Subtypes.

Background And Purpose: Research into the temporal relationship between atrial tachyarrhythmias (atrial tachycardia [AT] and atrial fibrillation [AF]) and stroke has produced conflicting findings. Systematic categorization of stroke subtypes may help clarify the discussion.

Objectives: The objective of the study was to examine the presence and timing of AT/AF in relation to ischemic stroke subtypes, categorized as either cardioembolic (CE) or non-CE.

Latent Causes of Sudden Cardiac Arrest.

Inherited arrhythmia syndromes are a common cause of apparently unexplained cardiac arrest or sudden cardiac death. These include long QT syndrome and Brugada syndrome, with a well-recognized phenotype in most patients with sufficiently severe disease to lead to cardiac arrest. Less common and typically less apparent conditions that may not be readily evident include catecholaminergic polymorphic ventricular tachycardia, short QT syndrome and early repolarization syndrome.

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.

Arrhythmogenic Right Ventricular Cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) encompasses a group of conditions characterized by right ventricular fibrofatty infiltration, with a predominant arrhythmic presentation. First described in the late 1970s and early 1980s, it is now frequently recognized to have biventricular involvement. The prevalence is ∼1:2,000 to 1:5,000, depending on geographic location, and it has a slight male predominance.

Brugada Syndrome.

Brugada syndrome (BrS) is an "inherited" condition characterized by predisposition to syncope and cardiac arrest, predominantly during sleep. The prevalence is ∼1:2,000, and is more commonly diagnosed in young to middle-aged males, although patient sex does not appear to impact prognosis. Despite the perception of BrS being an inherited arrhythmia syndrome, most cases are not associated with a single causative gene variant.

Sudden cardiac death related to physical exercise in the young: a nationwide cohort study of Australia.

Background: Sudden cardiac death (SCD) during physical exercise is devastating.

Aims: To evaluate causes and circumstances of exercise-related SCD in the young in Australia.

Methods: We reviewed the National Coronial Information System database for deaths in Australia relating to cardiovascular disease in cases aged 10-35 years between 2000 and 2016.

Epidemiology of cardiac implantable electronic device infections: incidence and risk factors.

Cardiac implantable electronic device (CIED) infection is a potentially devastating complication of CIED procedures, causing significant morbidity and mortality for patients. Of all CIED complications, infection has the greatest impact on mortality, requirement for re-intervention and additional hospital treatment days. Based on large prospective studies, the infection rate at 12-months after a CIED procedure is approximately 1%.

Relationship between QT interval prolongation and structural abnormalities in cirrhotic cardiomyopathy: A change in the current paradigm.

It is postulated that cardiac structural abnormalities observed in cirrhotic cardiomyopathy (CCM) contribute to the electrophysiologic abnormality of QT interval (QTc) prolongation. We sought to evaluate whether QTc prolongation is associated with intrinsic abnormalities in cardiac structure and function that characterize CCM. Consecutive patients undergoing liver transplant work-up between 2010 and 2018 were included.

Systematic quantification of histologic ventricular fibrosis in isolated mitral valve prolapse and sudden cardiac death.

Background: Cardiac fibrosis in mitral valve prolapse (MVP) is implicated in the development of sudden cardiac death (SCD); however, the pattern remains poorly characterized.

Objective: The purpose of this study was to systematically quantify left and right ventricular fibrosis in individuals with isolated MVP and SCD (iMVP-SCD), whereby other potential causes of death are excluded, compared to a control cohort.

Methods: Individuals with iMVP-SCD were identified from the Victorian Institute of Forensic Medicine, Australia, and matched for age, sex, and body mass index to control cases with noncardiac death.

Postoperative Atrial Fibrillation and Long-Term Risk of Stroke in Patients Undergoing Liver Transplantation.

Background And Purpose: Postoperative atrial fibrillation (POAF) is the commonest cardiovascular complication following liver transplantation (LT). This study sought to assess a possible association of POAF with subsequent thromboembolic events in patients undergoing LT.

Methods: A retrospective cohort study of consecutive adults undergoing LT between 2010 and 2018 was undertaken.

Sudden cardiac death following liver transplantation: Incidence, trends and risk predictors.

Background: Cardiovascular events are a leading cause of mortality following liver transplantation (LT). Although a preponderance of sudden cardiac death (SCD) in this population has been reported, there is a paucity of data evaluating the incidence, timing and predictors of SCD following LT.

Methods: Using the prospectively collected Australian and New Zealand Liver Transplant Registry, a cohort study of all adult LTs from 1985 to 2017 was performed to ascertain the incidence and predictors of SCD.

Effect of liver transplantation on QT-interval prolongation and impact on mortality.

Background: QT-interval prolongation is considered the electrophysiological hallmark of cirrhotic cardiomyopathy. However, the significance of QT-interval prolongation and how it is affected by liver transplantation (LT) remains unclear.

Methods: Consecutive inpatients undergoing LT between 2010 and 2017 at a state-wide liver transplant center in Australia were included.

Sudden Cardiac Death in the Young: Incidence, Trends, and Risk Factors in a Nationwide Study.

Background: Sudden cardiac death (SCD) in the young is devastating. Contemporary incidence remains unclear with few recent nationwide studies and limited data addressing risk factors for causes. We aimed to determine incidence, trends, causes, and risk factors for SCD in the young.

Effect of QT interval prolongation on cardiac arrest following liver transplantation and derivation of a risk index.

Liver transplantation (LT) has a 4-fold higher risk of periprocedural cardiac arrest and ventricular arrhythmias (CA/VAs) compared with other noncardiac surgeries. Prolongation of the corrected QT interval (QTc) is common in patients with liver cirrhosis. Whether it is associated with an increased risk of CA/VAs following LT is unclear.

Arrhythmia insensitive rapid cardiac T1 mapping: comparison to modified look locker inversion recovery T1 mapping in mitral valve prolapse patients.

We compare a saturation recovery arrhythmia insensitive rapid (AIR) T1 mapping technique which is less sensitive to heart rate and requires shorter breath-holds to modified Look-Locker inversion recovery (MOLLI) T1 mapping in patients with mitral valve prolapse. 55 patients underwent AIR and MOLLI at 1.5 T.

Prediction of Perioperative Cardiovascular Events in Liver Transplantation.

Background: Hepatorenal syndrome (HRS) is a serious complication of liver cirrhosis with poor survival in the absence of liver transplantation (LT). HRS represents a state of profound circulatory and cardiac dysfunction. Whether it increases risk of perioperative major adverse cardiovascular events (MACE) following LT remains unclear.