Aortic stenosis

Causes and risk

Etiology:

• The most common cause is calcification and degeneration of a congenitally normal valve, so the typical patient is old.
• Calcification and fibrosis of a congenitally bicuspid aortic valve.
• Rheumatic valvular disease. If the aortic valve is affected by rheumatic fever, the mitral valve is also invariably affected.

Supravalvular aortic stenosis is the most common cardiac finding in Williams syndrome, at 80%, ahead of peripheral pulmonic stenosis and pulmonary valvular stenosis.

How it presents

Symptoms come on with exertion. A 64-year-old male with mild shortness of breath and lightheadedness with exertion had a grade 3/6 systolic ejection murmur at the right second intercostal space radiating to the neck, and severe aortic stenosis. A 68-year-old female who used to walk 2 miles daily could no longer do so because of dyspnea and chest tightness, and she also had mild lower extremity edema.

The murmur is systolic, mid-systolic or systolic ejection in timing, and it radiates to the carotid arteries. That radiation is what sets it apart: mitral regurgitation radiates to the left axilla in the left lateral recumbent position, and pulmonary stenosis radiates to the interscapular region.

There is a long, asymptomatic latent period first, and symptoms often occur when the orifice size is reduced to 25% or less, that is less than 0.7 cm where the normal is 2-4 cm.

Then each of the three symptoms carries its own survival:

• Angina: survival 5 years.
• Syncope: survival 3 years.
• HF: survival 2 years.

Sudden death occurs in 10% of patients, most all of whom are symptomatic.