Aortic Stenosis

In most of cases it involves the aortic valve, located between the left ventricle and the aorta. When the valve is too small or dysplastic the spread is not sufficient and the space for blood flow is restricted. This induces a pressure overload of the left ventricle.

Normally left ventricle and aorta work at the same pressure level. When there is a stenosis, at the moment of the ventricular contraction, between the ventricle and the aorta there is a pressure difference, or a pressure gradient, which as much high as the stenosis is severe. For example in a severe aortic stenosis we can have a ventricle pressure of 200 mmHg at contraction time with an aortic pressure of 100 mmHg; in this case the gradient is 100 mmHg. The response at this feature is ventricular hypertrophy, hypertrophy which increase the coronary perfusion difficulties. During exercise the ventricular pressure increases more as well as the oxygen demand from the myocardium. Children with aortic stenosis can have myocardial ischemia which manifests with thoracic pain. Children with severe aortic stenosis can present syncope usually after exercise.

Fortunately most of the aortic valvular stenosis are not grave and the progression is slow. It is necessary to follow the children periodically to control the lesion evolution and establish the necessity of treatment. For moderate to severe stenosis it is generally necessary to limit physical activities (from the prohibition of sporting activities to limitation of any activity).

In some cases the aortic stenosis is subvalvular, due to the presence of membrane or fibromuscular protuberances which obstruct the left ventricle outflow. Rarely the stenosis is supravalvular.

Most part of aortic valvular stenosis can be cured, successfully in about 80% of cases, without surgery, using catheter balloon valvuloplasty. Generally the result is not good and persistent as in the pulmonary valve stenosis. In a second time surgery may necessary, consisting in an opening of the valve or in the substitution of the valve with a prosthetic valve or with the pulmonary valve of the same patient and the substitution the pulmonary valve with a prosthetic valve (Ross intervention)

The subvalvular an supravalvular stenosis always require surgery.

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