Active clinical trials for "Atrial Fibrillation"

Atrial fibrillation (Af) is the most common morbid event after open heart surgery. Its incidence ranges from 19% to 27%, as reported by the Society of Thoracic Surgeons database. Many groups have tried to understand and treat this difficult problem and have formulated different hypotheses to explain its origin. An imbalance of the autonomic nervous system after surgical intervention has been accepted as a major determinant for this morbidity. Ventral cardiac denervation is a fast and low-risk procedure. This intervention has shown significantly reduction of the incidence and severity of Af after routine coronary artery bypass surgery. This technique could be applied both on-pump or off-pump and used as an adjunctive procedure to achieve Af prophylaxis. However, the detailed mechanism remains unclear. Theoretically, heart receives its innervation from the autonomic nervous system (ANS) via the great vessels and pericardial attachment. The propensity and distribution of ANS nerve fibers are different in location. In this study, we would like to evaluate the ANS function after ventral cardiac denervation by using heart rate variability (HRV) and baroreflex (BRS) sensitivity. 30 patients proposed to have elective off-pump coronary artery bypass surgery are enrolled. After induction of anesthesia, the depth of anesthesia is controlled by inhalation agents and monitored by bispectral index. After the major cardiac operation, ventral cardiac denervation is performed by using electrocautery. The digital signals of heart rate and blood pressure are acquired before and after the surgical procedures under the same range of bispectral index (50~60). The paired HRV and BRS are analyzed. This will provide us more information to justify the procedure.

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.

The purpose of this pilot study is to determine if esophageal warming using the Attune Medical Esophageal Heat Transfer Device (EnsoETM) limits the frequency or severity of thermal injury during cryoballoon ablation of 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.

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.

The primary objective of this study is to evaluate whether, in patients with first-ever atherothrombotic or lacunar stroke without any previous history of atrial fibrillation (AF)/atrial flutter (AFL)/atrial tachycardia (AT), the detection of AF/AFL/AT (silent or symptomatic) by using a continuous cardiac rhythm monitoring with implantable loop recorder (ILR) during the first 12 months of observation is higher than the detection by using a standard cardiac monitoring (physical exam, 12-lead electrocardiogram [ECG] at baseline, 3, 6, and 12 months and Holter ECG at 3 months) in the same period of time.

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.

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).