Embolic stroke of undetermined source: A cardiovascular approach to diagnostic uncertainty.

Embolic stroke of undetermined source (ESUS) is a clinical event with an undelineated embolic etiology after the initial stroke workup. Once stroke specialists confirm ESUS, evaluation of rhythm disorders such as atrial fibrillation, specific cardiac pathologies (cardiomyopathy, left atrial cardiopathy, left-atrial septal pouch, aortic or mitral valve disease, cardiac neoplasm, right-to-left shunts, or device-related thrombus), and acquired hypercoagulable states, which may occasionally be related to malignancy, should be performed. While most ESUS patients require appropriate antiplatelet therapy, certain subsets may require oral anticoagulation. However, routine prescription of oral anticoagulants in the absence of documented atrial fibrillation, cancer-related thrombosis, or cardiac thrombosis is discouraged. Shared decision-making between the patient and the physician about additional diagnostic and therapeutic decisions is particularly encouraged in this condition, given the limited availability of high-quality clinical data and considerable uncertainty about the safety and efficacy of therapeutic options and clinical outcomes.