Quadricuspid Aortic Valve Combined with Moderate Ascending Aortic Dilatation: A Report of Four Cases.

The quadricuspid aortic valve is a very uncommon malformation associated with aortic insufficiency, aortic stenosis, endocarditis, and ascending aortic dilatation. We report four cases of this aortic valve malformation. One patient with severe aortic regurgitation and moderate aortic dilatation required aortic valve replacement.