Cardioembolic stroke in a young male with cor triatriatum sinister: a case report

Background Cor triatriatum sinister (CTS) is a rare congenital cardiac anomaly defined by a fibromuscular membrane which bisects the left atrium. Cor triatriatum sinister has been associated with cardioembolic stroke through mechanisms including stagnation of blood flow within the left atrium, an association with atrial fibrillation (AF), and/or an accompanying atrial septal defect (ASD) or patent foramen ovale. We describe a case highlighting the role that CTS may play in cardioembolic stroke, provide high-quality computed tomography angiography and two- and three-dimensional echocardiography of the CTS membrane, and outline management strategies for this uncommon clinical scenario. Case summary A 35-year-old man with no prior medical history presented with acute onset weakness and aphasia. He was found to have an embolic stroke with left M1 and A1 occlusions and received tissue plasminogen activator followed by mechanical thrombectomy with successful recanalization. A thorough stroke workup revealed CTS with an associated ASD as well as potential protein C deficiency. He was managed with indefinite anticoagulation with apixaban. Discussion This is the 13th reported case of CTS associated with stroke. In most previous cases evidence of blood stasis or frank thrombus was associated with the CTS membrane, and/or existing AF was noted. In this case, none of these were identified, particularly highlighting the surreptitious risk of CTS. In addition, the presence of potential protein C deficiency in this case compounded the risk for thromboembolism and factored into multidisciplinary management decisions.