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.
The Upper Midwest, or the North, is a region in the northern portion of the U.S. Census Bureau 's Midwestern United States. It is largely a sub-region of the midwest. Although there are no uniformly agreed-upon boundaries, the region is most commonly used to refer to the states of Minnesota, Wisconsin, and Michigan.ichigan, Illinois, and Wisconsin also often favor Democratic candidates. By contrast, the lower Midwest includes swing states such as Ohio, Missouri, and Iowa, and solidly Republican (until 2008) Indiana. The Plains States to the west are heavily Republican in most presidential contests.