Active clinical trials for "Atrial Fibrillation"

The RAPTURE Study will determine whether dual chamber defibrillators with atrial prevention and termination therapies, minimized ventricular pacing, and remote monitoring will reduce the rate of inappropriate shocks and improve quality of life compared to optimally programmed back-up pacing only single chamber ICDs when used for primary prevention of sudden cardiac death

Atrial fibrillation is a common and disabling irregular heart rhythm, that affects 1 to 1.5 million Americans. Recent clinical experience with the Medtronic Arctic Front™ Cardiac CryoAblation Catheter System suggests that it can be used to isolate the pulmonary veins (PVs) safely and effectively in patients with AF, thereby reducing or eliminating the recurrence of AF.3-4 However, the very large ablative surface of this balloon ablation catheter raises the possibility that this technique may damage extensive areas of the atrial myocardium. The LA is an elastic chamber, designed to expand and contract with ease to accommodate the influx and outflow of blood, while maintaining relatively low pressure. When exposed to stress or injury, whether acute or chronic, the LA may lose much of its elasticity, resulting in overall dilation accompanied by fibrosis in some cases. Overall, this may potentially result in diminution of LA mechanical function (both systolic contractile function, and diastolic relaxation function). In addition, LA function is linked to both Left Ventricular (LV) systolic and diastolic function, manifesting in an overall impact on cardiac remodeling, including the area of the pulmonary vein ostia, and a significant decrease in LV ejection fraction (LVEF). On the other hand, the positive effects of maintaining sinus rhythm with successful catheter ablation of AF may result in improvement of LA mechanical function.5-9 Based on the potentially deleterious effects of damage caused by cryoablation, to the atrial myocardium during balloon ablation, this prospective, non-randomized, single-center study has been designed to assess the atrial effects of balloon cryo-ablation.

Paroxysmal or chronic atrial fibrillation (AF) develops in about 20- 25% of adult patients with hypertrophic cardiomyopathy (HCM) and represents an important complication in the clinical course of the disease, with adverse long-term consequences on functional status and outcome. Therefore, aggressive therapeutic strategies are indicated to restore and maintain sinus rhythm (SR) in patients with HCM. Nevertheless, pharmacologic prevention of AF recurrence is challenging because of the limited long-term efficacy and potentially hazardous side effects of available treatment options. Currently radiofrequency catheter ablation (RFCA) of AF is successfully used in clinical practice. However, comparison of the efficacy and safety of these two therapeutic options has not been done up till now in randomized manner in this group of patients. Thus, the aim of the present study is to compare the efficacy and safety of RFCA vs. antiarrhythmic drug therapy in patients with HCM and AF.

Radiofrequency ablation is an effective treatment for atrial fibrillation. However, about 20% of the time the atrial fibrillation recurs. Steroids given after the ablation may decrease inflammation caused by the ablation and thus improve healing and decrease the chance of recurrence of atrial fibrillation. In this study patients will be randomized to receive intravenous steroids or not immediately following the ablation.

Warfarin is very effective for the prevention of blood clots (thrombosis). A test of coagulation, the prothrombin time (PT) is used to monitor the effect. The PT response to warfarin can fluctuate as a result of interactions with a large number of other drugs, food or herbal agents as well as for no apparent reason. Thus, frequent monitoring of the PT and dose adjustments according to the results are required. One third of our patients remain on the same maintenance dose over 6 months. However, also these patients sometimes have a PT result moderately outside the therapeutic range without any obvious explanation. Too short PTs may be due to missed dose(s) or more dark green vegetables in the diet. Too long PTs may be due to a course of antibiotic therapy or less dark green vegetables. Laboratory errors may also occur and can cause deviations in any direction. Most likely, unnoticed fluctuations in the PT occur as well between the time points of monitoring. There are no guidelines on how to manage the treatment in this situation but there are some typical "behaviours". Behavior A: Some physicians simply let the patient continue with the same dose. "It is extremely unlikely that the very temporary dose adjustment has any effect on the PT result 4 weeks later and this is a "cosmetic procedure"." Behavior B: Others recommend the patients to take ½ - 1 additional dose in case of short PT and to skip a dose or take half dose in case of long PT, and thereafter to continue with the usual dose. "The investigators need to quickly correct the temporary aberration in order to avoid thrombotic or bleeding complications the next few days. This may seem like an issue of no importance. The investigators are however performing a series of studies to evaluate if these stable patients can be managed with blood tests less often than every 4 weeks. For that purpose it is important to know how often and why aberrant results occur, the implication and to what extent they can be ignored. The investigators hypothesis is that in patients with very stable PT-results and unchanged dose for 3 months, should continue with exactly the same maintenance dose, even when the result unexpectedly is slightly above or below the therapeutic range. The investigators believe that most of these occasional PT-results outside the therapeutic range are due to laboratory errors, perhaps missed doses by the patient or temporary change in diet or medications.

Amiodarone is considered to be the most effective antiarrhythmic drug in the prevention of persistent atrial fibrillation. It can however cause many adverse events, both cardiac and non-cardiac. Long-term maintenance of sinus rhythm after cardioversion is difficult especially because of high recurrence rates during the first month after cardioversion. Duration of atrial fibrillation, type of underlying disease, left ventricular function, left atrial size and age are associated with maintaining sinus rhythm. Early recurrence of atrial fibrillation may be related to a highly arrhythmogenic period due to recovery from electrical remodelling. Late recurrences may be related to other triggers than recovery from electrical remodelling. In this study the investigators want to investigate the effect of amiodarone withdrawal on the occurrence of late relapses of persistent atrial fibrillation. Furthermore, the investigators want to investigate the effect of amiodarone withdrawal on the occurrence of amiodarone related adverse events as well as adverse events related to atrial fibrillation or underlying heart disease. The investigators also want to investigate which patients characteristics are and potential triggers have a prognostic value in the occurence of late relapses after amiodarone withdrawal.

Atrial fibrillation (AF) is a heart rhythm disorder that usually involves a rapid heart rate. People who take fish oil supplements may reduce the risk of a recurrence of AF. This study will evaluate the effectiveness of fish oil at decreasing the recurrence of AF and will examine the reasons why fish oil may reduce this risk.

This study (STOP AF) is a prospective, randomized, controlled, multicenter, pivotal clinical investigation conducted at 26 investigational sites in the United States and Canada. Subjects with paroxysmal atrial fibrillation (PAF) referred for ablative intervention after efficacy failure of one or more Study Atrial Fibrillation (AF) Drugs (flecainide, propafenone or sotalol) were randomized 2:1 to cryoablation intervention (Experimental Subjects, ES) or to a Study AF Drug (Control Subjects, CS). Subjects were followed for 12 months with scheduled and symptom-driven assessments to detect recurrent atrial fibrillation by means of periodic electrocardiograms, weekly scheduled trans-telephonic monitoring, patient-initiated trans-telephonic monitoring, and 24-hour Holter monitoring at 6 and 12 months. The first 90 days after study therapy was initiated was considered a blanked period for all subjects.

RESTORE-SR study is a multi-center, prospective, nonrandomized study with case matched concurrent controls to evaluate the safety and efficacy of the AtriCure Bipolar System

It is the purpose of the study to show the benefit of the endocardial catheter ablation by pulmonary vein isolation in patients with persistent or longstanding persistent atrial fibrillation, low LVEF and requiring ICD or CRT-D therapy compared to the best medical treatment with antiarrhythmic drugs.