Mitral insufficiency common cause of primary mitral regurgitation in the United States, causing about 50% of cases. Myxomatous degeneration of the mitral valve is more common in women as well as with advancing age, which causes a stretching of the leaflets of the valve and the chordae tendineae. Such elongation prevents the valve leaflets from fully coming together when the valve closes, causing the valve leaflets to prolapse into the left atrium, thereby causing MI. Ischemic heart disease causes MR by the combination of ischemic dysfunction of the papillary muscles, and the dilatation of the left ventricle. This can lead to the
Mitral insufficiency broad, notched P waves in several or many leads with a prominent late negative component to the P wave in lead V, and may be seen in MI, but also in mitral stenosis, and, potentially, any cause of overload of the left atrium. Thus, "P-sinistrocardiale" may be a more appropriate term. The degree of severity of MR can be quantified by the regurgitant fraction, which is the percentage of the left ventricular stroke volume that regurgitates into the left atrium. where V and V are, respectively, the volumes of blood that flow forward through the mitral valve and aortic valve