BACKGROUND: An accessory mitral valve leaflet is a rare congenital anomaly usually associated with left ventricular outflow tract (LVOT) obstruction. Fewer than 100 cases have been reported mostly occurring in children.

CASE: An asymptomatic 43-year-old female who came in for pre employment clearance was noted to have a systolic murmur. Echocardiography revealed an accessory mitral valve tissue attached to the anterior mitral valve leaflet. There was also a significant gradient noted across the LVOT. Patient is presently asymptomatic and she was advised follow up for serial echocardiographic monitoring.

DIAGNOSTICS: Twelve lead electrocardiogram showed normal sinus rhythm with normal axis, poor R wave progression and no chamber enlargement. Chest radiography was normal. 2D Echo revealed an echogenic, parachute-like structure billowing into the LVOT during systole. Interrogation of the said structure using Doppler revealed a significant pressure gradient of 45mmHg along the LVOT.

CONCLUSION: Accessory mitral valve with LVOT obstruction is an unusual finding. Clinical and echocardiographic recognition as well as surveillance is warranted in these patients. This is also important for determination of definitive management.