The aortic valve is a 1-way gate between the largest chamber of the heart, the left ventricle, and the rest of the body. Sometimes, as people age, the aortic valve stops opening properly and does not let enough blood through. This condition is called aortic stenosis. Some people with aortic stenosis do not have any symptoms. But if the condition becomes severe enough, people will often have dizziness, fainting, trouble breathing, or chest pain.