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“Stenosis” is the medical term for a blockage or narrowing of a passage. Critical aortic stenosis refers to the dangerous and extreme narrowing of the aortic valve in newborn babies.
The aortic valve is the passage through which blood flows out of the lower left chamber (the left ventricle) of the heart to reach the aortic artery, which circulates oxygenated blood to the body. Before birth, a baby can survive well with only one well-functioning ventricle due to unique blood flow patterns. That is not the case after birth. With critical aortic stenosis, the left ventricle is not able to pump blood adequately through the narrowed aortic valve into the aorta. As a result, a baby with this defect can become very ill soon after birth. Unless the condition is treated immediately, the condition can be fatal because the body is deprived of oxygenated blood.
Aortic valve stenosis (AS) is a disease of the aortic valves in which the opening of the valve is narrowed. When the opening of the aortic valve becomes narrowed or constricted (stenotic), the blood cannot be pumped adequately and the pressure in the left ventricle increases. Over time, the left ventricle compensates by thickening its walls in order to maintain adequate pumping pressure. In later stages, the left ventricle dilates, the wall thins, and the systolic function deteriorates.
A normal size aortic valve is the size of a half-dollar and a significantly stenotic valve may range in size of a dime to a pinhole.
Degree of aortic stenosis can be assessed by echocardiography and heart catheterization. In adults, critical aortic stenosis is defined as a mean gradient >70 mmHg and/or an aortic valve area of < 0.6 cm2.
When the aortic valve is severely stenotic, it may need to be replaced with a new valve. This is done surgically. However, percutaneous and catheter based procedures are available for patients who are not candidates for surgical valve replacement.
Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.