Active clinical trials for "Atrial Fibrillation"

In this randomised controlled cross-over study we will investigate whether intrathoracic pressure changes induced by simulated obstructive apnoea and hypopnoea trigger premature supraventricular and ventricular contractions as well as atrial fibrillation in patients with paroxysmal atrial fibrillation.

The purpose of the study is to evaluate the mechanisms of recurrent atrial fibrillation after cryoballoon ablation using the Arctic Front Ablation System. For those with pulmonary vein reconnection, specific sites of reconnection will be evaluated with left atrial intracardiac echo (ICE) guidance. The Achieve mapping catheter will be evaluated head-to-head with our current method of ICE-guided recordings from a conventional mapping catheter with high output pulmonary venous pacing.

The aim of the investigators study is to analyze the incidence of MES by TCD performed during AF ablation with the nMARQ and to compare is with the incidence of MES using a conventional irrigated ablation catheter. Objective: To investigate the incidence of MES on TCD during AF ablation with the nMARQ catheter compared to a conventional irrigated ablation catheter. Following inclusion, patients will be randomized into 2 equal different treatment groups: PVI with traditional irrigated RF catheter versus PVI using the nMARQ catheter. In all patients, anticoagulation therapy with warfarin is discontinued five-days before the procedure and low molecular weight heparin is initiated at that time. A CT-scan of the left atrium is performed and imported into the Carto 3 mapping system. The ablation procedure is conducted under general anesthesia or conscious sedation. A decapolar catheter is positioned in the coronary sinus and a quadripolar catheter is positioned at the His bundle level through the right femoral vein. Two 8F sheaths are introduced into the left atrium with double trans-septal puncture performed under fluoroscopic, trans-esophageal echocardiographic or intracardiac echocardiography guidance. Upon completion of the first trans-septal puncture, intravenous heparin is administered to maintain an activated clotting time of 350 seconds throughout the procedure. A variable Lasso circular mapping catheter is introduced through the SL1 sheath into each pulmonary vein for electrical mapping. After the second trans-septal puncture, a Navistar Thermocool 3.5mm irrigated ablation catheter or an nMARQ circular irrigated ablation catheter are introduced into the left atrium. Of note, in case of use the nMARQ catheter, the second SL-1 sheath is replaced by a steerable 8F agilis sheath after the second trans-septal puncture. Each of the 4 PVs are imaged by selective angiograms. The left atrium geometry is created using the nMARQ catheter or the Navistar catheter and then merged with the pre-acquired CT scan of the left atrium and PVs. Identification of true MESs will be possible using an event detector system, in addition to determining whether the MESs are attributed to a solid or to a gaseous embolus. Total MES counts will be collected and evaluated separately during different stages of the procedure.

We hypothesized that in patients with low CHADS-VASc score (2 or < 2), there is no difference in thromboembolic or bleeding events between patients with short term warfarin therapy (2 weeks after catheter ablation) and conventional therapy (3 weeks before and 8 weeks after procedure).

Patients with atrial fibrillation undergoing cardioversion will be randomized to undergo transesophageal echocardiography or they will receive warfarin for 3 weeks with an international normalized ratio (INR) value between 2.0-3.0. Those who do not want to use warfarin will be given an approved new oral anticoagulant agent istead of warfarin for 3 weeks. If thrombus is detected in left atrium or in left atrial appendage, no cardioversion will be performed. Other patients in the both groups will undergo electrical cardioversion. After the procedures all the patients will be given oral anticoagulant for at least 4 Weeks. All patients will have neurological examination and diffusion magnetic resonance imaging (MRI) at baseline and at postprocedural 7th day. Clinical and subclinical cerebral thromboembolic events detected by diffusion MRI will be recorded. Any bleeding events will also be recorded.

120 consecutive patients with paroxysmal AF, slated for PV isolation, will be randomly assigned to RF or cryoballoon ablation (in a 1:2 allocation scheme). Real-time 3D echocardiography (RT3DE) will be performed before the ablation procedure and 1 month post-ablation. The RT3DE datasets will be stored digitally and quantitative analyses will be performed off-line at a core echo laboratory. Quantification of left atrial volumes will be performed and left atrial functional quantification will be performed by calculating the following indices: Left atrial ejection fraction, Active atrial emptying fraction, Passive atrial emptying fraction, Atrial expansion index. All patients will be hospitalized for 48 hours post-ablation. Blood samples will be obtained at 12-hour intervals to measure troponin T with a high-sensitivity assay, as well as other biochemical parameters.

This study will evaluate the recurrence rates of atrial fibrillation that develops in the hospital following non cardiac procedures or surgeries or acute medical illnesses.

Pulmonary vein isolation is a widely used strategy for the treatment of patients with symptomatic atrial fibrillation. After successful pulmonary vein isolation (no atrial fibrillation on transtelephonic rhythm recordings for 3 months following ablation), heart rhythm is not routinely monitored. The goal of this study is to determine whether the Kardia Mobile device detects AF at a different rate compared to our standard of care. The study also hopes to understand how this Kardia Mobile device and Kardia Pro platform affect health care utilization and patient anxiety.

The Apple Heart Study (AHS) is a research study conducted to evaluate whether the Apple Heart Study App can use data collected on the Apple Watch to identify irregular heart rhythms, including those from potentially serious heart conditions such as atrial fibrillation. Up to 500,000 can participate in the study.

Atrial fibrillation (AF) is the most common sustained cardiac rhythm disorder. The most serious common complication of AF is ischemic stroke.The aim of this study is to investigate the yield of AF screening with a continuous ECG monitor (ECG247) and to estimate the prevalence of silent AF