LAUSR

Ischemic stroke is an important cause of morbidity and mortality increasingly contributing to disability-adjusted lifeyears worldwide [1]. According to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification [2], the etiology of ischemic stroke includes atherosclerosis of the large arteries, small-vessel occlusion, cardioembolism and stroke of other determined etiology (e.g. related to cardiovascular interventions) and cryptogenic stroke. Cryptogenic stroke comprises up to about 25% of ischemic stroke and is presumed to be mostly of embolic origin (about 17% of all ischemic stroke [3]). This leads to the definition of embolic stroke of undetermined source (ESUS), which is characterized by non-lacunar location in the absence of proximal arterial stenosis or an identified source of cardiac embolism [4]. While other stroke entities have plain therapeutic targets, ESUS incorporates various underlying diseases and entities for which medical, surgical or interventional treatment might be available but cannot be applied due to the lack of delineation. Several attempts were made to address this issue; however, despite recent improvements in imaging modalities and the diagnostic work-up, ESUS remains a relevant concern [3]. Presumed origins of ESUS are mostly located in the heart, such as in the left atrial