pseudo cor triatriatum sinistrum due to dilated coronary sinus in association with supramitral ring

We herein describe a 34-year-old woman with a persistent left superior vena cava (plsvc) impinging on the posterior wall of the left atrium, subdivided by a membrane at the distal part of the impingement. in this patient, a much dilated coronary sinus due to the plsvc resulted in a membrane-like structure in the posterior wall of the left atrium with the appearance of the cor triatriatum in transthoracic echocardiography (ie, a pseudo cor triatriatum). although the plsvc is a common malformation of the superior systemic vein, its aforementioned presentation is rare.