In most elderly adults, aortic stenosis is caused by a build-up of calcium (a mineral found in your blood) on the valve leaflets. Over time, this causes the leaflets to become stiff, reducing their ability to fully open and close.
But other causes, such as birth defects of the heart, rheumatic fever, and past radiation therapy, can lead to valve problems.
How aortic stenosis progresses
Aortic stenosis is a progressive disease, which means it gets worse over time. Because of this, doctors will typically measure it as mild, moderate, or severe aortic stenosis. The stage of aortic stenosis depends on how damaged your aortic valve is.
In the mild and moderate stages of aortic stenosis, the decrease in blood flow is usually not significant enough to cause outward symptoms. In fact, many people are unaware they have the condition or may be told they have a heart murmur during a routine check-up. As the leaflets become more damaged, the opening of the aortic valve becomes more narrowed. This causes your heart muscle to become weaker because it needs to work harder to pump the needed amount of blood and oxygen throughout the body.
Once your aortic stenosis becomes severe, you may notice uncomfortable symptoms such as shortness of breath or fatigue. When this happens, it can be life-threatening, so it is important to tell your doctor as soon as you think you have symptoms or your symptoms worsen.
Bouma BJ, van den Brink RBA, van der Meulen JHP et al. To operate or not on elderly patients with aortic stenosis: the decision and its consequences. Heart 1999 Aug; 82: 143–8.
Nikomo VT, Gardin JM, Skelton TN et al. Burden of valvular heart diseases: a population–based study. Lancet 2006;368:1005–11.
Baumgartner H, Falk V, Bax JJ et al. 2017 ESC/EACTS Guidelines for the management of valvular heart disease: The Task Force for the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS). Eur Heart J. 2017; 38:2739–91.