Active clinical trials for "Cardiac Conduction System Disease"

Cardiac pacing is the only effective treatment for symptomatic bradycardia. The right ventricular apex (RVA) has become the most frequently used ventricular pacing site. However, RVA pacing has been shown to cause left ventricular (LV) dyssynchrony wich can lead to LV dysfunction and development of heart failure. Recent studies in animals have demonstrated that pacing at the LV septum induces significantly less ventricular dyssynchrony than RVA pacing and is able to improve LV function to a similar degree as biventricular (BiV) pacing. In addition it was shown that a LV septum lead can be placed permanently by driving a lead with extended helix from the RV side through the inter-ventricular septum into the LV endocardial layer. This was shown to be a feasible and safe procedure and lead stability was shown during four months of follow-up in otherwise healthy and active canines. LV septum pacing may therefore be a good treatment alternative in patients with symptomatic bradycardia, as well as patients with an indication for cardiac resynchronization therapy (CRT). The purpose of this study is to translate the findings from preclinical studies to the clinical situation by investigating the feasibility, long-term lead stability and safety of LV septum pacing by transvenous approach through the inter-ventricular septum in patients.

Antiarrhythmic drugs are associated with significant side effect profiles. Amiodarone has primarily class III action and whilst it has unrivalled efficacy in management of certain arrhythmias, it has a formidable side effect profile. Complications of continued therapy include, thyroiditis, hepatitis, cholestasis, increased skin sensitivity and pulmonary fibrosis. Current prescribing guidelines recommend frequent blood tests to monitor kidney, liver and thyroid function, in addition to frequent pulmonary function tests. Sotalol is a betablocker which possesses class III action in high doses and may predispose to QT prolongation Other class I agents such as flecainide and propafenone can be associated with sudden cardiac death in certain populations, and may predispose to other arrhythmias. This study will examine the incidence of discontinuation of AAD therapy and adverse events.

This is a prospective observational study, the purpose of which is to: Characterize response of the AV conduction system to TAVR with various prostheses by recording continuous His bundle electrograms during valve placement. Correlate preprocedure ECG features with changes in AV nodal and infranodal conduction during placement of the valve prosthesis. Correlate changes in AV nodal and infranodal conduction during the procedure with risk of developing AV conduction block after TAVR. Assess the contribution of stressing the conduction system by atrial pacing prior to and following TAVR to prediction of postprocedural heart block. Assess the correlation between new onset bundle branch block, site and degree of conduction block or delay and subsequent development of high-grade or complete AV block.

Connective tissue diseases have been related to heart conduction disorders. The anti-Ro/SSA antibodies are thought to have a pathogenic role, and they most prevalent in systemic lupus erythematous (SLE). The aim of this study is to evaluate the relationship between SLE, arrhythmias and its serologic profile.

Conduction disturbances are a major complication of TAVI. There is no predictor of post-TAVI conduction disorder. The study of the membranous septum on the pre-TAVI scanner and the valve implantation height are promising and little studied data on the occurrence of post-TAVI conduction disorders.

The investigators are conducting a prospective, observational study to examine the ECG waveforms captured by the new medical device as compared to a traditional Holter monitor for subsequent use in visual diagnoses of atrial and ventricular arrhythmias as well as cardiac impulse and/or conduction disorders by qualified clinicians. The hypothesis is that this new medical device prototype is non-inferior to traditional Holter monitoring for capturing ECG waveforms that can be visually assessed for atrial and ventricular arrhythmias as well as disorders of cardiac impulse formation and/or conduction.

Observational study to assess AV block incidence and their evolution according to paroxysmal atrial arrhythmia.

Non-invasive reconstruction of electrical heart activity can yield important scientific and clinical insights in cardiac rhythm disorders. In this study, The investigators aim at developing methods for reconstructing electrical heart activity non-invasively, and to use these methods to investigate cardiac rhythm disorders to answer clinical and scientific questions.

Background: Disturbances of the heart's atrioventricular conduction - AV-block - may show by shortness of breath, fainting or sudden death. If AV-block is diagnosed in time pacemaker therapy may be lifesaving. AV-block in younger can be seen along with structural or ischemic heart disease, congenital heart disease (incl. congenital AV-block) storage disorders, specific muscle diseases, sarcoidosis, Borrelia infection or drug intoxication. AV-block in younger can also be seen in conditions, primarily localized to the AV-node without other cardiac disease at diagnosis. This form of AV-block is often hereditary and can be seen in families where relatives have another types of heart disease in form of fore example, cardiomyopathy, ion channel disease or sudden death. The different forms of presentation are due to the same gene mutation being expressed differently within the same family. Thus, early onset of AV-block (<50 years) may indicate hereditary AV-conduction disorder but it can also be the first manifestation of severe ion channel disease or cardiomyopathy. Denmark has annually over 50 individuals <50 years treated with pacemaker due to advanced AV-block. There have been no overall figures regarding the causes of advanced AV-block, and therefore no systematic approach to diagnosing this group of patients. Furthermore, the prevalence of individuals with a genetic cause of AV-block is unknown and presumably an often overlooked diagnosis among younger patients with advanced AV-blok. There are no data on disease progression after diagnosis, and therefore there is no evidence-based knowledge about how these patients should be followed after diagnosis. With modern gene technology, a range of new, yet unknown genes with potentially pathogenic mutations is likely to be identified. Identification of such genes, and the development of a strategy for systematic approach to diagnose younger patients with AV-block, will enable presymptomatic genetic screening of relatives and implementation of evidence-based, preventive treatment with pacemaker and/or medical treatment for heart failure based on a specific genetic predisposition for development of AV-block with or without heart failure. Hypotheses: In a significant proportion of younger patients with advanced AV-block the underlying cause is unknown. Objective: To investigate the prevalence and causes of advanced AV-block in younger patients in Denmark and describe the current diagnostics. Method: The study is a cross sectional study. The patients for this study are identified from Danish Pacemaker and ICD Register. The investigators will review medical records and obtain clinical information and test results (see detailed description). Perspectives: This study is the first part of a large study of AV-block in younger patients in Denmark. The overall goal, is to increase knowledge about the causes of and disease progression after the diagnosis of advanced AV-block in young patients which could lead to a significant improvement in the treatment of this patient group and may lead to a customized choice of pacemaker type in the future and perhaps additional medical treatment in this patient group. This could potentially lead to a reduction in both their morbidity mortality.

Identification of genes involved in congenital atrioventricular block and progressive Cardiac Conduction Disease.