Absence of circulating microemboli in patients with lone atrial fibrillation

Atrial fibrillation (AF) is a well-recognized independent risk factor of is chemic stroke. The aim of this study Mras to investigate the amount of micr oembolic signals (MES) in 15 patients with 'lone' AF representing the subgr oup of AF patients with the lowest lifelong risk of stroke. All patients ha d been put on effective anticoagulation due to a scheduled electric cardiov ersion. Additional cardiac and arterial sources of embolism were excluded b y echocardiography and extracranial color-coded duplex sonography of the ca rotid arteries. Unilateral one-hour transcranial Doppler monitorings reveal ed complete absence of MES in this series. This observation fits the concep t that the amount of microembolisation is related to the risk of manifest t hromboembolism. Further studies on this patient group treated with less int ensive antihemostatic therapy should be undertaken to define more clearly t he disease-specific microembolic activity.