The aim of the study was to evaluate if the incidence of LASC and LAT in patients with atrial fibrillation (AF) having implantable devices and which undergone an elective EC is higher than in the case of patients without implantable devices. The increased risk of thromboembolic complications was lowered by using the anticoagulation therapy. The presence of an implanted device in patients with AF was correlated with a higher incidence of left atrial spontaneous contrast (LASC) and left atrial thrombi (LAT).