It is the abnormal leaking of blood backwards from the left ventricle, through the mitral valve, into the left atrium, when the left ventricle contracts, i.e. there is regurgitation of blood back into the left atrium. MI is the most common form of valvular heart disease.t is the abnormal leaking of blood backwards from the left ventricle, through the mitral valve, into the left atrium, when the left ventricle contracts, i.e. there is regurgitation of blood back into the left atrium. MI is the most common form of valvular heart disease.
Illinois is the most populous of the states and North Dakota the least. A 2012 report from the United States Census put the population of the Midwest at 65,377,684. The Midwest is divided by the Census Bureau into two divisions. The East North Central Division includes Illinois, Indiana, Michigan, Ohio and Wisconsin, all of which are also part of the Great Lakes region.
However, as david argues, the midwest region globally includes many areas outside of what we traditionally refer to as the midwest, USA. It seems to me that the term midwest arose domestically (likely before 1884), not as a global indicator. Read this from North Dakota State University: http://www.ext.nodak ...