Active clinical trials for "Atrial Fibrillation"

The purpose of this study is to determine if the combination of clopidogrel 75mg once daily (od) plus aspirin 100mg daily (recommended dose) is better than aspirin alone (100mg daily recommended dose) for preventing vascular events such as stroke and heart attack during approximately three years of follow-up in patients with atrial fibrillation associated with at least one major risk factor of vascular event such as elderly, blood pressure increase, history of stroke or transient ischemic attack or left ventricular dysfunction etc. The study will also accept patients with atrial fibrillation and unwilling to take oral anticoagulant therapy.

This is a prospective comparison of clinician dosing and a pharmacogenetic algorithm in diagnosed patients requiring warfarin therapy.

The aim of this randomized controlled study is to evaluate whether a newly designed electronic warning system will increase the initiation rate of adequate stroke preventive measures in patients with atrial fibrillation.

Stroke is a leading cause of mortality, morbidity and rising healthcare cost worldwide. In 'real-world' practice, AF is often diagnosed too late at time of stroke and detection can be difficult because AF may be present without symptoms and intermittent in nature. Furthermore, utilization of adequate oral anticoagulation therapy (OAC) for stroke prevention is suboptimal in Hong Kong. The challenge is to identify AF prior to occurrence of stroke. The latest European guidelines recommend opportunistic screening for people >=65 years by pulse palpation followed by 12-lead ECG. However, 12-lead ECG requires a trained technician, time consuming, requires the patient to lie on an examination couch and is not readily available in most outpatient clinics in Hong Kong. A practical screening test is needed. Our study aims to evaluate the feasibility, acceptability and incremental cost of an outpatient based AFscreening program using the AliveCor device. Newly diagnosed AF patients will be randomized to routine care versus individualized stroke prevention strategy which consists of patient education, stroke and bleeding risk assessment, evidence-based OAC recommendation, patient audit and follow-up to improve OAC utilization for stroke prevention. We envisage this study will provide timely evidence to inform policy decisions concerning population-based AF-screening for AF for stroke prevention.

Atrial fibrillation(AF) is the most common sustained arrhythmia in humans. The loss of rate-dependent action potential duration(APD) adaptation is one of the characteristics of atrial fibrillation, but detailed understanding of mechanism is limited. Thus, we propose to utilize the monophasic action potential recording data from human patients in three groups, control, paroxysmal and persistent atrial fibrillation, and apply reverse engineering method to quantify the extent of electrical remodeling of ionic channel parameters using a mathematical model of atrial cell. Our approach will be useful in developing drug targets for ion channels in atrial fibrillation patients.

Atrial fibrillation (AF) is associated with impaired cognitive function (CogF) and/or dementia, but it is unclear whether rhythm control of AF improves CogF or brain perfusion. The hypothesis is rhythm control of AF improves CogF by increasing brain perfusion with hemodynamic amelioration compared to AF state. We will randomize the patients with persistent AF to rhythm control group and rate control group, and check baseline and 3rd month cognitive function (K-MOCA score) and brain perfusion CT. K-MOCA score and brain perfusion CT findings will be compared between rhythm control group and rate control group of persistent AF.

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.

Objectives: Despite utilization of available means for cardioprotection during cardiac surgery, myocardial injury still occurs. Further improvement of cardioprotection is therefore necessary. Remote ischemic preconditioning (RIPC) is an easy and non-invasive method. Laboratory research has shown promising results regarding myocardial survival during open heart surgery, but the clinical value of RIPC is still largely unknown. The investigators hypothesize that RIPC before coronary artery bypass grafting (CABG) reduces the incidence of postoperative atrial fibrillation (POAF).

This study is to determine, through continuous monitoring with the Reveal implantable cardiac monitor (ICM), the incidence of atrial fibrillation (AF) in patients suspected to be at high risk for having AF and to understand how physicians manage these patients after AF has been detected. This study will also seek to identify what patient characteristics are most predictive of developing AF.

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.