Normally functioning quadricuspid aortic valve mistaken for bicuspid valve in a septuagenarian.

A 70-year-old male underwent transthoracic (TTE) and transesophageal (TEE) echocardiography for a stroke. A bicuspid aortic valve was suspected by TTE, but TEE revealed a normally functioning quadricuspid aortic valve. A quadricuspid aortic valve may be more common than generally thought, as it may not be readily diagnosed by TTE, and may remain functionally normal.