Density-dependent colour scanning electron micrograph of cardiovascular calcification, showing in orange calcium phosphate spherical particles (denser material) and, in green, the extracellular matrix (less dense material). The human<unk>  valve normally consists of three cusps or leaflets and has an opening of 3.0-4.0 square centimeters. When the left ventricle contracts, it forces blood through the valve into the aorta and subsequently to the rest of the body. When the left ventricle expands again, the<unk>  valve closes and prevents the blood in the aorta from flowing backward (regurgitation) into the left ventricle. In<unk> , the opening of the<unk>  valve becomes narrowed or constricted (stenotic) (e.g., due to calcification). Degenerative (the most common variety), and bicuspid<unk>  both begin with damage to endothelial cells from increased mechanical stress. Inflammation is thought to be involved in the earlier stages of the pathogenesis of AS and its associated risk factors are known to promote the deposition of LDL cholesterol and lipoprotein(a), a highly damaging substance, into the<unk>  valve, causing significant damage and<unk>  over time. As a consequence of this<unk> , the left ventricle must generate a higher pressure with each contraction to effectively move blood forward into the aorta. Initially, the LV generates this increased pressure by thickening its muscular walls (myocardial hypertrophy). The type of hypertrophy most commonly seen in AS is known as concentric hypertrophy, in which the walls of the LV are (approximately) equally thickened. In the later stages, the left ventricle dilates, the wall thins, and the systolic function deteriorates (resulting in impaired ability to pump blood forward). Morris and Innasimuthu et al. showed that different coronary anatomy is associated with different valve diseases. Research was in progress in 2010 to see if different coronary anatomy might lead to turbulent flow at the level of valves leading to inflammation and degeneration.
Aortic stenosis
Hypertrophic cardiomyopathy
Mitral stenosis
Aortic regurgitation
Tricuspid valve stenosis
Tricuspid regurgitation
Mitral regurgitation
Pulmonary valve stenosis