An Unusual Cause of Cardioembolic Stroke: Paradoxical Embolism Due to Thrombus Formation on the Eustachian Valve

Cardioembolism is an important cause of ischemic stroke, with several studies showing worse outcome than following other stroke subtypes. Paradoxical embolism is a rare cause of cardioembolic stroke. We report a case of a patient with presumed paradoxical cardioembolic stroke secondary to thrombus formation on the eustachian valve remnant in the right atrium. The patient was anticoagulated with resolution of the mass upon follow‐up assessment. The diagnostic, investigative and management strategies are discussed for patients with suspected paradoxical embolism causing stroke. Physicians are reminded of the utility of echocardiography for identifying potential cardioembolic etiologies, including both transthoracic and transesophageal echocardiography.