AORTIC STENOSIS
AORTIC STENOSIS
AORTIC STENOSIS
is a condition where the aortic valve has become tight.
The valve becomes stiff and calcified and cannot open effectively.
The heart must perform more work to move enough blood out of the heart thru the tight valve.
It would more properly be termed AORTIC VALVE STENOSIS but almost everyone shortens it.
A normal aortic valve has 3 leaflets. The leaflets are the parts which move, which open and close with each heartbeat.
In a closed position, the leaflets resemble a Mercedes-Benz symbol and the leaflets touch in the middle.
Normal aortic valve lealfets are thin and pliable and move very easily.
Notice how smooth these normal leafets appear, and how they are thin - you can almost see thru them.
These normal leaflets will open easily, meaning it takes very little force to move the leaflets out of the way.
And when these normal leaflets open, they open completely, nearly touching the wall of the aorta, allowing for a lot of space for the blood to move out of the heart.
Aortic valve leaflets can become calcified - where calcium collects in the leaflets - making them hard and stiff.
Notice how thick these stenotic leaflets appear, and how irregular and bumpy they are - you can imagine how they do not move as easily as normal leaflets.
And when these stenotic leaflets open, they will not open completely, they only open a little bit. This smaller opening restricts the blood moving out of the heart.
This smaller opening can get as small as 0.6 cm2 or so, which is about the size of a pea.
If the same amount of blood is going to move thru the valve, then the blood must move faster if moving thru a smaller opening.
An analogy is putting your finger over the end of a water hose. The reduction in space forces the water to move faster. As such, the water will also shoot farther.
When the blood moves faster thru the valve, the blood can produce an abnormal sound. The abnormal sound is a murmur.
Often, aortic stenosis is first suspected because a murmur is heard. Generally, the worse the stenosis, the louder the murmur.
An echo cardiogram can make the diagnosis. An echo is a fancy ultrasound.
Measurements can be made via echo to determine how severe the stenosis is.
With severe stenosis, the heart may struggle to produce enough force to open the valve and get the proper amount of blood out.
The body cannot fix aortic stenosis. There is no known way to remove calcium from the leaflets and make them move better again.
There is no medication that can remove calcium from the leaflets.
There are no vitamins or supplements shown to halt or reverse the process, either.
Surgery to replace the stiff, stenotic leaflets is the only therapy which effectively eliminates the problem of the stiff leaflets and extra work for the heart to open them.
Not every patient with aortic stenosis needs an operation, of course.
Scientific studies have been done to help determine when an operation should be considered for patients with AS.
These studies have shown that patients can live for a long time with some aortic stenosis.
However, once the patient begins to experience symptoms, there is a dramatic change and many patients will not survive for long.
In general, once patients have symptoms from severe AS, about 50% of patients will not be alive in 2 years.
The symptoms patient experience are shortness of breath, chest pain, and passing out.
Often, patients do not report shortness of breath but instead they cut out the activities which would cause them to feel short of breath.
Often patients assume they are feeling tired and run down because they are just getting older - which may be true! But it may also be that their heart is struggling.
Sometimes the heart will struggle so much that it becomes weak.
It is preferable to provide the patient with surgery prior to the heart becoming weak.
Though no patient wants heart surgery, one satisfying aspect of aortic valve replacement for AS is that patients can live for many years.
So whereas patients have a 50% chance of living for 2 years without surgery (once they have symptoms), patients can live many years after AVR and often a problem other than their heart is the ultimate cause of death.
When it comes to aortic valve replacement, there are several options.
FREQUENTLY ASKED QUESTIONS
Q: What causes aortic stenosis?
A: It is unclear exactly why some patients get AS and others do not. About 50% of patients have senile AS, which is age-related calcification of the valve leaflets. But it is not like the patients ate too much calcium or anything like that. The calcification is thought to be related in some way to inflammation. About 30-40% of cases of AS involve a bicuspid aortic valve, which is a valve with 2 leaflets instead of the normal 3. And about 10% of cases are from rheumatic fever, where scar tissue forms on the valve, narrowing it.
Q: How common is aortic stenosis?
A: AS is the most common heart valve disease in the US. It is estimated to affect roughly 2 million people!
Q: What happens if a person tries to ignore AS?
A: AS almost always worsens over time. As the valve becomes tighter and the heart works harder to pump the blood out, the person becomes increasingly tired and run down. If the person does not seek medical attention, the heart will struggle more and more and eventually become unable to provide enough blood to the body. Generally, a person does not "drop dead" from AS in this process but rather it is a slow, progressive process. Still, there are some patients who get worse quickly and frequent visits to the hospital can be common.
Q: My doctor says I have a murmur - should I be worried?
A: A murmur is the sound caused by abnormal blood flow. A murmur may or may not represent a problem that is unsafe. Often, a patient may have a murmur for many years and the patient requires no particular intervention. However, if you have been found to have a new murmur, this should be fully investigated by a specialist, usually a cardiologist.
Normal aortic valve lealfets are thin and pliable and move very easily.
Notice how smooth these normal leafets appear, and how they are thin - you can almost see thru them.
These normal leaflets will open easily, meaning it takes very little force to move the leaflets out of the way.
And when these normal leaflets open, they open completely, nearly touching the wall of the aorta, allowing for a lot of space for the blood to move out of the heart.
The usual amount of space for the blood to flow with the leaflets fully out of the way is 3-4 cm2. This is roughly the size of a quarter.