Effect of moderate potassium-elevating treatment in long QT syndrome: the TriQarr Potassium Study.

Background: In long QT syndrome (LQTS), beta blockers prevent arrhythmias. As a supplement, means to increase potassium has been suggested. We set to investigate the effect of moderate potassium elevation on cardiac repolarisation.

Long QT syndrome type 1 and 2 patients respond differently to arrhythmic triggers: The TriQarr in vivo study.

Background: In patients with long QT syndrome (LQTS), swimming and loud noises have been identified as genotype-specific arrhythmic triggers in LQTS type 1 (LQTS1) and LQTS type 2 (LQTS2), respectively.

Objective: The purpose of this study was to compare LQTS group responses to arrhythmic triggers.

Methods: LQTS1 and LQTS2 patients were included.

Long QT syndrome is associated with an increased burden of diabetes, psychiatric and neurological comorbidities: a nationwide cohort study.

Objective: Studies have suggested a shared genetic aetiology between congenital long QT syndrome (LQTS) and diabetes, epilepsy and mental disorders. We investigated the prevalence of metabolic, neurological and psychiatric comorbidities in LQTS patients.

Methods: This retrospective cohort study was based on data from nationwide Danish registries, 2003-2017.

Screening relatives in arrhythmogenic right ventricular cardiomyopathy: yield of imaging and electrical investigations.

Aims: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited disease and presymptomatic screening of relatives is recommended. In 2010, the Task Force Criteria (TFC2010) introduced specific diagnostic imaging parameters. The aim of the study was to evaluate the diagnostic yield of family screening and the value of different diagnostic modalities.

Long-term proarrhythmic pharmacotherapy among patients with congenital long QT syndrome and risk of arrhythmia and mortality.

Aims: It is Class I recommendation that congenital long QT syndrome (cLQTS) patients should avoid drugs that can cause torsades de pointes (TdP). We determined use of TdP risk drugs after cLQTS diagnosis and associated risk of ventricular arrhythmia and all-cause mortality.

Methods And Results: Congenital long QT syndrome patients (1995-2015) were identified from four inherited cardiac disease clinics in Denmark.

Citalopram and the KCNE1 D85N variant: a case report on the implications of a genetic modifier.

Background: Prolongation of the QT interval on the electrocardiogram is clinically important due to the association with an increased risk of sudden cardiac death. A long QT interval may be genetically determined (congenital long QT syndrome) or be drug-induced long QT syndrome e.g.

Clinical characteristics and lipid lowering treatment of patients initiated on proprotein convertase subtilisin-kexin type 9 inhibitors: a nationwide cohort study.

Objectives: Given the novelty of proprotein convertase subtilisin-kexin type 9 inhibitors (PCSK9i), little is known regarding overall implementation or clinical characteristics among patients who initiate treatment. We aimed to assess the total number of patients initiated on PCSK9i along with a description of the clinical characteristics and lipid lowering treatment (LLT) of such patients.

Setting: A register-based descriptive cohort study of patients receiving a PCSK9i in the time period from 01 January 2016 to 31 March 2017 using a cross linkage between three nationwide Danish registers.

Exercise-induced left bundle branch block - A case report with stress-echocardiographic assessment.

We report the case of a 51-year-old male who presented with exertional chest discomfort and dyspnea concurring with an exercise-induced left bundle branch block (EI-LBBB). Possible underlying causes and treatment options are presented and discussed. The case represents the first stress-echocardiographic assessment of a case with EI-LBBB, performed in order to document a possible left ventricular dyssynchrony during the EI-LBBB and thereby the possible treatment option of biventricular pacemaker implantation.

Late potentials and their correlation with ventricular structure in patients with ventricular arrhythmias.

Introduction: The presence of late potentials (LP) may indicate a predisposition to ventricular arrhythmias and sudden cardiac death. We investigated the association between presence of LP and structural cardiac anomalies assessed by magnetic resonance (CMR) in patients presenting with ventricular arrhythmias.

Methods: We included 42 patients admitted with ventricular tachycardia or fibrillation who had undergone both signal-averaged ECG recording and CMR imaging.

Presymptomatic diagnosis of Fabry's disease: a case report.

Background: Fabry's disease is a rare X-linked genetic disorder characterized by reduced levels of the α-galactosidase A enzyme. It may present with a cardiac phenotype resembling hypertrophic cardiomyopathy. However, as a specific enzyme replacement therapy is available, it remains an important differential diagnoses in patients presenting with cardiac hypertrophy.

Clinical evaluation of unselected cardiac arrest survivors in a tertiary center over a 1-year period (the LAZARUZ study).

Objectives: When the cause of an aborted cardiac arrest is unclear the initiation of therapy, counseling and family screening is challenging.

Methods: We included 43 unselected, prospectively identified cardiac arrest survivors with or without a diagnosis. Family history for cardiac disease and supplemental electrocardiograms were evaluated for additional diagnostic information.

Cardiac magnetic resonance imaging after ventricular tachyarrhythmias increases diagnostic precision and reduces the need for family screening for inherited cardiac disease.

Aims: Guidelines recommend evaluation of family members of sudden cardiac death victims. However, initiation of cascade screening in families with uncertain diagnoses is not cost-effective and may cause unnecessary concern. For these reasons, we set out to assess to what extent cardiac magnetic resonance imaging (CMR) would increase the diagnostic precision and thereby possibly change the indication for family screening in patients with ventricular tachyarrhythmias.

Mutations in Danish patients with long QT syndrome and the identification of a large founder family with p.F29L in KCNH2.

Background: Long QT syndrome (LQTS) is a cardiac ion channelopathy which presents clinically with palpitations, syncope or sudden death. More than 700 LQTS-causing mutations have been identified in 13 genes, all of which encode proteins involved in the execution of the cardiac action potential. The most frequently affected genes, covering > 90% of cases, are KCNQ1, KCNH2 and SCN5A.

Cascade screening in families with inherited cardiac diseases driven by cardiologists: feasibility and nationwide outcome in long QT syndrome.

Objectives: We assessed the outcome of cascade screening of families with congenital long QT syndrome (LQTS) in Danish heart centers.

Methods: Affected family members were identified through systematic family screening.

Results: In total, 228 affected relatives were identified from 90 families.

Differences in investigations of sudden unexpected deaths in young people in a nationwide setting.

Background: Inherited disease may be causative in many young sudden unexpected death cases. Autopsy is essential in the counselling of the bereaved, as the family of the victim may be at risk too. In a nationwide setting operating under the same set of laws, we hypothesized that regional differences exist in the investigation of young persons dying suddenly and unexpectedly.

Sudden unexpected death in infancy in Denmark.

Background: Incidence of sudden unexpected death in infancy (SUDI) and sudden infant death syndrome (SIDS) differs among studies and non-autopsied cases are difficult to assess.

Objectives: To investigate causes of sudden death in infancy in a nationwide setting. Validate the use of the ICD-10 code for SIDS (R95) in the Danish Cause of Death registry.

Nationwide study of sudden cardiac death in persons aged 1-35 years.

Aims: The aim of this investigation was to study the incidence of sudden cardiac death (SCD) in persons aged 1-35 years in a nationwide setting (5.38 million people) by systematic evaluation of all deaths.

Methods And Results: All deaths in persons aged 1-35 years in Denmark in 2000-06 were included.

[Catecholaminergic polymorphic ventricular tachycardia is a rare inherited heart disease].

Catecholaminergic polymorphic ventricular tachycardia is a rare inherited heart disease, which can lead to life-threatening ventricular arrhythmias in patients with a structurally normal heart. The age of onset is usually between two and 12 years and the initial symptom is frequently syncope or cardiac arrest. The arrhythmias are usually triggered by exercise or emotional affection.

Incidence and etiology of sports-related sudden cardiac death in Denmark--implications for preparticipation screening.

Background: Studies on incidences of sports-related sudden cardiac death (SrSCD) are few and data are needed for the discussion of preparticipation screening for cardiac disease.

Objective: We sought to chart the incidence and etiology of SrSCD in the young in Denmark (population 5.4 million) and to compare this to the incidence of sudden cardiac death (SCD) in the background population.

The prevalence and relevance of the Brugada-type electrocardiogram in the Danish general population: data from the Copenhagen City Heart Study.

Aims: The prevalence of the Brugada-type electrocardiogram (ECG) in the Danish population is not known.

Methods And Results: Inhabitants from the city of Copenhagen, Denmark, have participated in a prospective study since 1976. Four cross-sectional surveys have been carried out.

Genetic variation in the inwardly rectifying K channel subunits KCNJ3 (GIRK1) and KCNJ5 (GIRK4) in patients with sinus node dysfunction.

Background: Sinus node dysfunction (SND) is a heterogeneous disorder of unknown etiology characterized by a variety of supraventricular arrhythmias with symptoms of syncope, palpitations, and dizziness. The mechanism underlying the abnormal rhythm is incompletely understood.

Objective: Because vagal stimulation and acetylcholine (ACh) affect the function of pacemaker cells, we hypothesized that genetic variation in the genes encoding the ACh-activated K(+) channels, the KACh channels, could be involved in the pathogenesis of SND.

S100A4 is upregulated in injured myocardium and promotes growth and survival of cardiac myocytes.

Objective: The multifunctional Ca2+-binding protein S100A4 (also known as Mts1 and Fsp1) is involved in fibrosis and tissue remodeling in several diseases including cancer, kidney fibrosis, central nervous system injury, and pulmonary vascular disease. We previously reported that S100A4 mRNA expression was increased in hypertrophic rat hearts and that it has pro-cardiomyogenic effects in embryonic stem cell-derived embryoid bodies. We therefore hypothesized that S100A4 could play a supportive role in the injured heart.

Role of G-protein-coupled receptor kinase 2 in the heart--do regulatory mechanisms open novel therapeutic perspectives?

G-protein-coupled receptor kinase (GRK) 2 regulates a plethora of cellular processes, including cardiac expression and function of key seven-transmembrane receptors (7TM receptors) such as the beta-adrenergic and angiotensin receptors (Penela P, Murga C, Ribas C, et al.: 2006. Mechanisms of regulation of G-protein-coupled receptor kinases [GRKs] and cardiovascular disease.