Heart valve or cusps. The mitral valve gets its name from the resemblance to a bishop's mitre (a type of hat). It is on the left side of the heart and allows the blood to flow from the left atrium into the left ventricle. During diastole, a normally-functioning mitral valve opens as a result of increased pressure from the left atrium as it fills with blood (preloading). As atrial pressure increases above that of the left ventricle, the mitral valve opens. Opening facilitates the passive flow of blood into the left ventricle. Diastole ends with atrial contraction, which ejects the final 30%
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