Active clinical trials for "Bundle-Branch Block"

In patients undergoing CRT device implantation a lead positioning in the coronary sinus is required. Even this part of the surgical procedure is challenging. In this study we compared retrospectively to methods of CS-lead implantation: conventional vs. EP-catheter guided.

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.

This study is to determine 1) the incidence of altered right bundle conduction, including CRBBB, IRBBB or rsR' pattern in the Taipei city based on the school survey databank from 1999 to 2002, 2) the associated cardiac lesions, 3) clinical presentations relevant to the altered right bundle conduction, 4) the association with QTc prolongation and dispersion and HRV from a 5-minutes recording. Finally, molecular characterization for those with CRBBB or Brugada pattern EKG, especially those with positive family history will be studied.

TAVI induced LBBB is a complication that occurs between 7 and 65 % of the cases, numbers that differ considerably between devices. There is an increased risk of progression to total AV-block at follow-up, with the risk of brady-arrhythmic death. The aim of the study is to elucidate the anatomical location of the conduction pathology of a TAVI induced LBBB. This could impact valve design and placement and thereby reduce the number of new LBBB induced by TAVI in the future. Furthermore, finding predictors for progression to a high degree AV block in the follow-up (and thus an indication for permanent pacemaker) could improve management of post-operative conduction abnormalities and prevent the risk of brady-arrhythmic death.