What Is Aortic Stenosis?

Your aortic valve controls the flow of blood from the lower left chamber of the heart (the left ventricle) into the aorta (the main artery that carries blood from the heart to the body). Aortic stenosis occurs when this valve narrows and blood can no longer flow normally. The condition can range from mild to severe.

Over time, aortic valve stenosis forces the left ventricle to pump harder to push blood through the narrowed valve. This extra effort can cause the left ventricle to thicken, enlarge and weaken. Left untreated, this form of heart valve disease can lead to heart failure.

Stenosis of the Main Artery’s Valve: Causes

Aortic stenosis can be congenital, although it is far more often an acquired defect, usually the result of a degenerative process and less often a consequence of rheumatic heart disease. The most common cause of aortic stenosis is a degenerative process that leads to calcification of the valve leaflets, beginning at their base and gradually covering their entire surface.

Risk factors for degenerative changes in the aortic valve leaflets include:

  • male sex,
  • old age,
  • hypertension,
  • diabetes,
  • lipid disorders,
  • chronic kidney disease,
  • hypercalcaemia,
  • smoking,
  • overweight and obesity.

Thanks to the wide availability of medical care in developed countries, including treatment in Switzerland, and the early use of antibiotics for streptococcal pharyngitis, the incidence of rheumatic heart disease is low, and valve defects of this origin are rare. In such cases they form through the fusion of the connective elements of the leaflets, their scarring and, ultimately, as with degenerative lesions, calcification.

Among congenital defects of the aortic valve, the most common is the bicuspid valve. Because of its structure it undergoes degenerative processes faster than a tricuspid valve, leading to progressive calcification.

Aortic Stenosis: Symptoms of Aortic Stenosis

Aortic stenosis can remain without symptoms for many years (asymptomatic). The condition, which can be congenital, is therefore often diagnosed at a young age. Symptoms of aortic stenosis may appear later, many years afterwards. They may begin suddenly or gradually.

The patient may experience the following symptoms associated with aortic stenosis and its consequences:

  • chest pain caused by ischaemia of the heart muscle,
  • palpitations, caused by disturbances in the rhythm and conduction of impulses through the thickened heart muscle,
  • blurred vision,
  • dizziness,
  • near-fainting, caused by reduced cardiac output through the narrowed valve and by conduction blocks resulting from pressure on the impulse-conducting cells, which under normal conditions allow the contraction to “spread” across the entire heart muscle,
  • shortness of breath on exertion and at rest, in advanced disease,
  • difficulty breathing after physical exertion,
  • a cough that worsens at night,
  • episodes of loss of consciousness,
  • a general feeling of tiredness.

Aortic Stenosis: Treatment

Aortic stenosis can develop over many years and remain asymptomatic for a long time. However, the appearance of the first symptoms (palpitations, angina pectoris, fainting) significantly worsens the patient’s prognosis (survival from the onset of symptoms is around 2–3 years). Symptomatic patients with severe aortic stenosis therefore require surgical treatment without delay, including replacement of the narrowed valve.

Surgery is the treatment of choice. Two main surgical procedures are used for aortic stenosis.

  • The first is balloon valvuloplasty: a catheter is inserted into a blood vessel through an incision in the groin and advanced to the heart. The tip of the catheter is placed in the aortic valve and a balloon is inflated. This helps to stretch and widen the valve and improve blood flow into the aorta. The procedure does not cure the disease, and further surgery may be needed later in life. It is usually limited to people with congenital aortic stenosis, mainly children and adolescents.
  • The second, more radical option is aortic valve replacement: if the valve is too badly damaged, it can be surgically replaced with an artificial valve. Sometimes the patient’s own pulmonary valve may be used. This procedure is called a pulmonary autograft, or the Ross procedure.