An unusual cause of aortic regurgitation: accessory mitral valve

Accessory mitral valve (AMV) is a rare congenital cardiac anomaly that has been reported in 1 in 26,000 people in an echocardiography series. Most cases of AMV are associated with other cardiac abnormalities. Although patients with AMV are usually asymptomatic, syncope, exercise intolerance, and chest pain are described in patients with left ventricular outflow (LVOT) obstruction. Here we present the case of an asymptomatic child with a diagnosis of AMV using transesophageal echocardiography (TEE) images. A 17-year-old boy was diagnosed with suspected AMV during the evaluation of a cardiac murmur. Because he had no other associated anomalies, aortic regurgitation (AR), or LVOT obstruction, he had been followed up for 8 years by serial transthoracic echocardiography. However, the last echocardiography revealed a mild AR. Therefore, TEE was performed to confirm the diagnosis. AMV was clearly demonstrated without LVOT obstruction (Fig. 1 and Video 1). Surgical excision of AMV was performed because of new development of AR (Fig. 2). There was no AR and mitral regurgitation in the postoperative period. Surgical excision of AMV has some difficulties and can be complicated because after initiation of cardiopulmonary bypass, Figure 1. There is an accessory mitral valve image in TTE window