Functional systolic anterior motion of the mitral valve due to accessory chordae.

Accessory mitral valve tissue is an uncommon finding, usually associated with other congenital cardiac malformations and diagnosed during childhood. We present the case of a 70-year-old patient referred to our hospital for aortic valve and ascending aorta replacement. At preoperative examination, no evidence of mitral valve structural abnormalities was detected. Anaesthesia induction was complicated by sudden haemodynamic impairment. Intraoperative transoesophageal echocardiography showed two anomalous mitral chordae. The presence of abnormal mitral tissue also allowed to assess the mechanism of unexpected haemodynamic worsening: anomalous chordae caused anterior displacement of the anterior mitral leaflet, resulting in left ventricular outflow tract obstruction and mitral regurgitation. Medical therapy was instituted and the planned surgical approach was modified according to the new anatomy observed at echocardiographic examination. A valve-sparing technique was successfully applied. This case provides a good example of the diagnostic usefulness of routine intraoperative transoesophageal echocardiography, especially when facing unexpected findings. It also shows how transoesophageal echocardiography may help guide medical and surgical treatment.