Extrait

Background and study aims Atrial fibrillation (AF) is a common heart condition affecting around 2% of the UK population. When a patient suffers from AF the atria (upper chambers in their heart) stop pumping. This alters the heart rhythm, and can make the heart beat quickly and erratically. It happens because the electrical signals that normally control the atria are disturbed. AF usually begins as short ‘stop – start’ episodes lasting minutes to hours. Gradually these episodes become longer and occur more frequently. AF is a serious condition that can cause stroke and heart failure. Patients with AF are more likely to be admitted to hospital, have a lower life expectancy and can experience severe symptoms. Drugs designed to prevent AF are frequently ineffective and can be dangerous, so procedures that negate or reduce the need for drug treatment are of great importance. Catheter ablation (CA) is a surgical technique which is used to destroy the areas of the heart which are sending out the irregular signals. In the procedure, a thin flexible tube (catheter) is inserted into a major artery in the groin and guided up to the heart. The tip of the catheter then burns (radiofrequency ablation) the affected areas. This procedure is often very successful, and can completely cure AF in some cases. Variation in the thickness of the atrial wall is a significant cause of CA treatment failure. No tool exists to measure wall thickness throughout the atrium. Such a tool would provide the operator with information regarding the necessary – and safe - amount of cauterisation to apply in different areas. The research team has developed a technique to measure atrial wall thickness from computed tomography (CT or ‘CAT’) scans which provides a map of atrial wall thickness in three dimensions. The aim of this study is to find out how well this tool is able to measure atrial wall thickness in patients with AF who are planned for CA procedures, compared to those who are not. Who can participate? Adults with AF who have an AF/AT ablation planned and adults of the same age who have been referred to have a CT scan and have no history of AF. What does the study involve? Patients with AF undergo a CT scan to assess the thickness of their left atrial wall. In addition, they wear a 24 hour heart monitor and have a cardiac magnetic resonance (CMR) scan (a type of heart scan) as part of their normal care. Those who undergo CA have these tests repeated and answer a questionnaire about their health and current symptoms one year later. Patients without AF undergo a CT scan as part of their usual care. In addition, they wear a 24 hour heart monitor and have a cardiac magnetic resonance (CMR) scan (a type of heart scan) as part of their normal care. The results of these tests are then compared to the patients with AF. What are the possible benefits and risks of participating? The additional imaging will provide additional information about heart structure that would not be available otherwise and in some cases may be valuable. Heart rhythm monitoring in the patients without AF may identify asymptomatic (symptomless) heart rhythm disorders. There are no notable risks associated with participating. Where is the study run from? St Thomas' Hospital (UK) When is the study starting and how long is it expected to run for? October 2015 to April 2018 Who is funding the study? Medical Research Council (UK) Who is the main contact? Dr John Whitaker [email protected]

Critère d'inclusion

• Atrial fibrillation

Liens

• isrctn