A hazardous materials placard is a diamond-shaped sign that must be affixed to any motor vehicle that carries hazardous materials. Ordinarily, it has a four digit number in the middle of the placard and a one digit number at the bottom that shows the hazard class and specific material being carried.
Aortic stenosis is abnormal narrowing of the aortic valve. A number of conditions cause disease resulting in narrowing of the aortic valve. When the degree of narrowing becomes significant enough to impede the flow of blood from the left ventricle to the arteries, heart problems develop. The oxygenated blood then returns to the left atrium and passes through the mitral valve into the left ventricle. 2  Blood is pumped by the left ventricle across the aortic valve into the aorta and the arteries of the body.
Aortic valve replacement can relieve aortic valve stenosis and its symptoms. Transcatheter aortic valve replacement (TAVR). Aortic valve replacement, the most common treatment for aortic valve stenosis, has traditionally been performed with open-heart surgery.