Giant Eustachian Valve Mimicking an Inter-atrial Septal Defect

Abstract

A 68-year-old woman presented with dyspnoea attributed to acute pulmonary oedema. Due to an audible diastolic murmur, a transthoracic and transoesophageal echocardiogram (TEE) was performed revealing severe rheumatic mitral stenosis and regurgitation. Although initial assessment of the interatrial septum did not reveal any atrial septal defects, upon TEE evaluation using a 112° window, an interatrial defect was seen, with turbulent flow seen through this. However, using multiplanar imaging, a separate elongated Eustachian valve was shown to be mimicking an ‘arm’ of the interatrial septum and giving rise to the illusion of a defect. The Eustachian valve is a congenital remnant which often regresses at birth but can exist as an elongated structure originating from the inferior portion of the right atrium and may appear as an atrial septal defect. By employing multiplanar imaging on TEE, we were able to systematically discern the reason behind the apparent defect and avoid further delays to the patient’s care.