Active clinical trials for "Atrial Fibrillation"

The Elucidation of the Influence of Sleep Apnea on Risk of Atrial Fibrillation study. The study involves a case control design to investigate the extent to which there is an independent relationship of sleep disordered breathing (SDB) and paroxysmal atrial fibrillation (PAF). Cases will be defined as clinically identified patients with PAF and controls as those without AF. In order to rigorously address important biologic confounding influences, the cases and controls will be individually matched based upon age, gender, race, and body mass index. Those participants with both PAF and SDB (Apnea Hypopnea Index, AHI>=15) will be asked to return for a follow up exam after 3 months of SDB treatment in the Clinical Research Unit (CRU) for collection of the same measures collected at the baseline exam to observe for any significant changes with the purpose of collecting effect size data to inform future clinical trials. The total duration of the study is 4 years. The duration for any individual participant is up to from one to 13 weeks months, including a 3-month treatment period for those with moderate to severe SDB, i.e. AHI>15.

Warfarin is an anticoagulant medication that is highly effective at preventing clotting disorders but which has a narrow therapeutic window. If warfarin is under effective patients are at risk of stroke, if it is over effective patients are at risk of bleeding complications. Physicians routinely and regularly measure a blood test (called the "INR") that determines the effectiveness of warfarin and have a range of test values (the "therapeutic range") in which they try to keep the patient. By convention warfarin is taken at dinnertime, however this is the same time of day that highly variable consumption of dietary vitamin K occurs (found largely in green leafy vegetables) and vitamin K alters the effectiveness of warfarin. Given vitamin K has a very short half-life (i.e. it is only active for a short period of time after it is ingested) it may make more sense to take warfarin in the morning (when very little vitamin K is ingested) to produce a more consistent drug effect. The purpose of this study is to determine whether switching current warfarin users from evening to morning dosing decreases time spent outside the therapeutic INR range.

The purpose of this study is to evaluate the effect on distance covered in a 6 minute walking test of Rate Responsive pacing in patients with permanent atrial fibrillation and reduced left ventricular ejection fraction treated with atrioventricular junction ablation and biventricular pacing.

The objective of this study is to utilize delayed enhanced cardiac magnetic resonance imaging to assess the success of pulmonary vein isolation after cryoablation of paroxysmal atrial fibrillation. The primary hypothesis is that cardiac magnetic resonance imaging will be able to visualize changes in left atrial tissue characteristics caused by cryoablation used to treat paroxysmal atrial fibrillation.

Atrial fibrillation confers up to 5-fold increased risk of stroke in the absence of valvular heart disease. Although epidemiological studies have linked various clinical and echocardiographic risk factors to stroke, the exact mechanism of increased risk of stroke in AF remains poorly understood. Previous reports have suggested that loss of effective atrial contraction because of AF is associated with thrombogenesis. Microthrombi are most likely to form in the left atrial appendage. In contrast, intravascular thrombotic events in patients without AF are generally associated with abnormalities of vascular endothelial function and/or the coagulation system. On the assumption that more than 90% of all cardiac thrombi in patients with AF form in the LA appendage, and the fact that thrombi have been identified in 15-20% of patients with AF who have clinical risk factors for ischemic stroke, it has been deemed to be "our most lethal attachment". Administration of anticoagulant therapy is generally thought to be necessary as a preventive measure for patients at high risk of thromboembolism, but data indicating inadequate implementation of this highly effective therapy]. Several studies have found regional differences in platelet activation and hypercoagulability in the LA compared with systemic circulation in patients with valvular and nonvalvular AF, suggesting local contributing factors. Animal studies have demonstrated increased platelet activation and endothelial dysfunction with acute AF. The ability of antiplatelet agents to reduce the risk of cardioembolic events in AF suggests that platelets may contribute to the pathophysiology. Platelet activation occurs with AF and rapid atrial pacing, providing a possible mechanistic link. Other biomarkers that have proposed to improve the prediction of thromboembolotic events in this patient population include von Willebrand factor and D-dimer and cerebral imaging. A comprehensive understanding of the pathophysiological sequence leading to thrombus formation in the LAA of patients with AF could be helpful to characterize those at high risk for thromboembolic events, and subsequently to optimize the management of high risk patients.

The purpose of this study is to compare standard manual and robotically controlled catheter ablation of the cavo-tricuspid isthmus (CTI) as a treatment for atrial flutter. Ablation of the CTI is standard treatment for patients with a history of atrial flutter, and those undergoing ablation for atrial fibrillation. Both manual and robotic catheter manipulation are used in standard clinical practice at The University of California, San Diego (UCSD) for ablation.

Digoxin is the primary cardiac glycoside in clinical use. Because of the narrow therapeutic index and risk of toxicity, therapeutic drug monitoring is highly recommended. In Egypt, most cardiologists give digoxin holiday for both atrial fibrillation and heart failure, it is not clear if the interrupted digoxin regimens are effective since serum digoxin concentrations might fall below the therapeutic range. Objective: To evaluate and compare the digoxin serum concentration and patient's quality of life in the continuous versus interrupted digoxin dosing regimens.

The primary objective of this study is to establish the safety and performance effectiveness of the DiamondTemp System for the treatment of drug refractory, recurrent, symptomatic paroxysmal atrial fibrillation (PAF).

The purpose of this study is to evaluate the effectiveness of Pulmonary Vein Isolation (PVI) performed with the Arctic Front™ Advance Cardiac CryoAblation Catheter System as first-line therapy in comparison with antiarrhythmic drugs (AAD) in patients with paroxysmal atrial fibrillation (AF).

The aim of this prospective randomized double-blind study was to compare the efficacy and safety of Botulinum toxin injection in epicardial fat pads for preventing recurrences (in early postoperative period) of atrial tachyarrhythmia in patients with paroxysmal atrial fibrillation undergoing coronary artery bypass graft (CABG) surgery.