What is Aortic Stenosis?
The aortic valve is the main heart valve through which all of the blood flow must pass on its way out of the heart to the whole body.
Aortic stenosis is a narrowing of the aortic valve opening that does not allow normal blood flow. It is commonly caused by the aging process and occasionally by a birth defect, rheumatic fever, or radiation therapy. Aortic stenosis is one of the most life-threatening conditions associated with a heart murmur.
When blood leaves the heart, it flows from the main pumping chamber (the left ventricle) through the aortic valve and into the aorta, the main artery leaving the heart. In aortic stenosis, the aortic valve does not open fully. This restricts blood flow. Aortic stenosis may be present from birth (congenital), or it may develop later in life (acquired).
Memorial Hermann offers a unique minimally-invasive treatment for severe aortic stenosis called TAVR. Learn more.
Causes of Severe Aortic Stenosis
In elderly patients, severe aortic stenosis is often caused by the build-up of calcium (mineral deposits) on the aortic valve's leaflets. Over time the leaflets become stiff, reducing their ability to fully open and close. When the leaflets don't fully open, your heart must work harder to push blood through the narrowed aortic valve to your body.
Eventually, your heart gets weaker, increasing the risk of heart failure (a condition in which your heart cannot supply enough blood to your body).
Half of people with aortic stenosis who are experiencing activity-related symptoms will die within an average of two years. Since symptoms of aortic stenosis may not be present until the disease has progressed in severity, early detection is vital. Those who are diagnosed with this serious disease early and begin treatment have significantly higher survival rates.
Symptoms of aortic stenosis include:
- Breathlessness with activity
- Fainting, weakness or dizziness with activity
- Sensation of feeling the heart beat (palpitations)
- Chest pain, angina-type
- Crushing, squeezing, pressure, tightness
- Pain increases with exercise, relieved with rest
- Under the chest bone, may move to other areas
What Does Aortic Stenosis Look Like?
The leaflets of a healthy aortic heart valve allow oxygen-rich blood to flow unobstructed in one direction. The blood flows through the valve into the aorta where it then flows out to the rest of the body.
The leaflets of a stenotic aortic valve are unable to open wide, obstructing blood flow from the left ventricle into the aorta. The narrowed valve allows less blood to flow through and as a result, less oxygen-rich blood is pumped out to the body.
U.S. Aortic Stenosis Disease Prevalence & Treatment Statistics
- While up to 1.5 million people in the U.S. suffer from aortic stenosis (AS), approximately 500,000 within this group of patients suffer from severe AS. An estimated 250,000 patients with severe AS are symptomatic.
- An echocardiogram (echo) is the primary imaging test used to diagnose severe AS.
- Without an aortic valve replacement (AVR), 50 percent of patients will not survive more than an average of two years after the onset of symptoms.
- The predicted survival of inoperable patients with severe AS who are treated with standard non-surgical therapy is lower than with certain metastatic cancers.
- An estimated 85,000 AVR procedures are performed every year in the U.S.
What is Heart Murmur?
Four valves control the flow of blood through the chambers of the heart and out of the heart. The heartbeat sounds are the sounds of the valves closing.
A heart murmur is an extra sound besides the first and second heart sounds. The extra sound is created by the turbulent blood flow created when an aortic valve does not close tightly (such as with mitral regurgitation) and blood leaks backward. They can also occur when the blood flows though a narrowed or stiff valve (such as with aortic stenosis).