A tropical climate can be observed in Nicaragua. Just as in the other Central American countries, there are two seasons: the dry and the raining season. During the dry season (January - June) there is virtually no rain and trees and plants start to dry out.
Causes of aortic valve regurgitation include: 1  Congenital heart valve disease. 2  You may have been born with an aortic valve that has only two leaflets (bicuspid valve) or fused leaflets rather than the normal three separate leaflets. 3  This puts you at risk of developing aortic valve regurgitation at some time in your life.
The mitral valve (not to be confused with the congenital bicuspid aortic valve) and the tricuspid valve are known collectively as the atrioventricular valves because they lie between the atria and the ventricles of the heart and control the flow of blood.itral stenosis is a narrowing of the valve. This can be heard as an opening snap in a heart sound which is not normally present. Classic mitral valve prolapse is caused by an excess of connective tissue that thickens the spongiosa layer of the cusp and separates collagen bundles in the fibrosa.