MRI imaging of a left atrial mass misinterpreted by transesophageal echocardiography

An atrial mass: the value of echocardiographic three-dimensional reconstruction

An 88-year-old lady was referred to our Heart Failure Clinic with a history of 'occasional' breathlessness. Electrocardiography showed sinus rhythm and no other major abnormalities and N-terminal pro-B-type natriuretic peptide (NT-proBNP) was normal. Transthoracic echocardiography showed a non-dilated left ventricle with good systolic function. A bright and well-circumscribed, echogenic mass appeared inside a mildly dilated left atrium, visible in both parasternal and apical views. A three-dimensional echocardiographic reconstruction showed no mass within the left atrium; however, an extracardiac mass impinging its posterior wall was seen. Suspicion of an intrathoracic tumour was raised and cardiac magnetic resonance showed a hiatus hernia immediately adjacent to the left atrium. Care must be taken when evaluating masses in or close to the heart.