The most common congenital cardiac anomaly is a bicuspid aortic valve.

A bicuspid aortic valve is considered a connective tissue disorder. The aortic valve is normally tricuspid or trileaflet. When two of the cusps are fused together, the valve becomes functionally "bicuspid." Most commonly, the right and left coronary cusps are fused; least commonly, the left and noncoronary cusps are fused. This results, over time, in increased wear of the leaflets since the hemodynamic stress is distributed to only two cusps instead of three. Aortic valve stenosis or aortic valve regurgitation result. An ascending aortic aneurysm frequently develops concomitantly.

A systolic ejection click frequently indicates a bicuspid aortic valve. This sound is heard just after the first heart sound (S1). Usually, the opening of the aortic valve is not audible; however, with a bicuspid aortic valve the leaflets “dome” suddenly prior to opening, which creates a systolic ejection click. The click may be difficult to hear in the presence of significant aortic stenosis.

The treatment is surgical replacement when symptoms from aortic stenosis or aortic regurgitation develop. Also, an ascending aortic aneurysm has a lower threshold for repair in the setting of a bicuspid aortic valve and should be done if the diameter reaches > 5.0 cm.