The aortic valve controls blood flow between the left ventricle and the aorta, the vessel that delivers oxygen-rich blood to the body. There are two main problems that can occur with the aortic valve: it can become hardened and narrowed (stenosis), or it can leak (regurgitation). The most common problem in the elderly is called age-related calcific degeneration, where the gradual buildup of calcium causes the valve to narrow. Symptoms of aortic stenosis include lightheadedness, chest pain, shortness of breath and fatigue. In patients who are at high-risk of complications in surgery, the aortic valve can be replaced by transcatheter aortic valve implantation (TAVI).