The reasons:
Rheumatic valvular stenosis (soldering and calcification usually occurs along the edges of the valves). Fibro-calcific aortic stenosis (valve degenerative changes are associated with collagen destruction and accumulation of calcium deposits in the valves : this process begins in the sinus region of Valsalva and extends to the cusps. Congenital valve stenosis.
The end result of all the above forms of aortic valve stenosis is the fusion of commissures and narrowing of the aortic orifice. When degeneration and calcification of the valve develop, it is practically impossible to differentiate these conditions.
EchoCG changes in this defect are due to the syndrome of systolic LV overload In the M- and B-modes, the following signs are usually revealed: 1. a change in the morphology of the AK leaflets (fibrosis or calcification); 2. decrease in the degree of divergence of the AK leaflets in systole less than 15 mm (normal 18-20 mm); 3. an increase in the expulsion period from the LV more than 350 ms (normally up to 330 ms); 4. marked hypertrophy of the LV walls (usually more than 15 mm). When Doppler study from the top, you can estimate the degree of stenosis according to systolic pressure gradient (Rao): minimum stenosis – pressure gradient up to 20 mm Hg (at least 8 mm), moderate –40 mm Hg, expressed to 80 mm Hg and extremely pronounced above 80 mm Hg. However, this method of measurement is not possible in all patients. There are other ways to estimate the pressure gradient on the aortic valve:
Rao = adsis. – (Tzs / KSRlzh) x 245, where, Rao – pressure gradient on the aorta, BPM – systolic blood pressure, Tzs – thickness of the posterior wall of the left ventricle, KSRlzh – final systolic size of the LV. It is necessary to emphasize that when reducing the area of the joint-stock company hole by 20 – 40% (the norm is more than 2.5 cm 2 ), it practically does not affect the work of the heart and hemodynamic parameters suffer only if its area becomes less than 1.5 cm 2 .
Calcification and reduction of divergence Doppler flow in AK stenosis of AK valves up to 11 mm