<unk>  is a rare congenital anomaly and usually found at surgery or diagnosed preoperatively during echocardiographic examination or aortography. 
The most common hemodynamic abnormality associated with this anomaly is aortic insufficiency.
Quadricuspid aortic valve
Quadricuspid pulmonary valve
Double orifice mitral valve
Supravalvular aortic stenosis
Subvalvular aortic stenosis
Accessory auricle
Bicuspid aortic stenosis
Calcific aortic valve disease