From Dr. El Sabbagh: We use diameter measurements in managing aortic dilatation. We do not use diameter measurements of the aortic valve itself. Remember the aortic valve is connected to the aorta and if you were told that there is a diameter cut off, then this is probably alluding to what I mentioned, which is the aortic dilatation. It depends on many factors including the underlying cause of your aortic dilatation, such as bicuspid aortic valve or a connective tissue disease, as well as family history. If your aortic diameter is more than 3.5-4 cm, then you should follow-up with your cardiologist for investigating the cause and device thing a follow-up plan to monitor closely the rate of aortic dilatation.