The aortic valve is the valve that lets blood flow out of the heart, from the left ventricle (the heart’s main pumping chamber) into the aorta (the large blood vessel that carries blood to the rest of the body). Ordinarily, this valve has 3 leaflets that are arranged to produce a pattern much like the Mercedes Benz emblem, if you look at the valve from above. With each heartbeat, the leaflets open nearly completely, allowing for unobstructed blood flow out of the heart.
There are 2 main problems that happen with heart valves….the valve can leak or it can become obstructed. Today, we’re going to focus on narrowing of the aortic valve, that produces obstruction to blood flow, and this is a condition that we call aortic stenosis. We’ll leave the leaking valves to another day.
There are several causes of aortic stenosis, but, by far, the most common cause is age-related calcific degeneration of the valve. That is, over years and years, calcium deposits build up in the valve leaflets, making them immobile. The leaflets eventually become so stiff that they do not open properly….and produce obstruction to blood flow exiting the heart. Aortic stenosis is usually a problem for patients who are in their 60’s, 70’s, or even older. Because the problem develops gradually over many years, patients sometimes don’t notice the effects, but the 3 primary symptoms are: 1) shortness of breath with exertion; 2) chest pain; and 3) syncope (blacking out).
Patients come to medical attention because of one or more of the hallmark symptoms or occasionally because a physician hears a heart murmur. There is a characteristic sound, or murmur, associated with aortic stenosis and your physician can hear this murmur in a very particular location on the chest—just to the right of the sternum, above the level of the nipples. An echocardiogram (ultrasound) is used to make detailed pictures of the heart valves and can be used to quantify the degree of stenosis, or obstruction, as mild, moderate, severe, or critical.
Aortic stenosis is a serious medical problem. Patients with severe or critical aortic stenosis require valve replacement. There is no other treatment (ie, medicines) that can correct the problem. For patients with breathing difficulties because of their aortic stenosis, the average life-expectancy is less than 2 years without valve replacement. Major heart surgery is needed to replace the valve with a mechanical (eg, carbon fiber and metal) or tissue (eg, the aortic valve “borrowed” from a pig) valve.
But like I mentioned above, aortic stenosis can sometimes be encountered in a much younger patient….sometimes as young as in the 20’s. And this is often due to a congenital abnormality of the aortic valve in which there are only 2—and not the standard 3—leaflets. This occurs in 1-2% of the general population. For some reason, this arrangement predisposes the individual to earlier calcification and stenosis of the valve as well as leaking of the valve. This is relevant to the athlete because problems are likely to develop during the very active portion of a typical athlete’s active lifetime.
The second important consideration in patients with bicuspid aortic valve is that they are much more likely to develop enlargement (aneurysm) of the beginning portion of the aorta, as it leaves the heart. Over time, the aorta can enlarge from its typical diameter of less than 3 cm to 5 cm or more, the aorta and the aortic valve should be replaced….again, with major heart surgery