Mitral stenosis is a narrowing or blockage of the opening of the mitral valve, which separates the upper and lower chambers on the left side of the heart Mitral Stenosis is the leading cause of congestive heart failure in developing countries. . Mitral stenosis is a narrowing of the mitral valve in the heart This prevents proper blood flow from moving between the left atrium (upper chamber of the heart) and ventricle (lower chamber of the heart) This in turn means there is a reduced amount of blood that is pumped out into the body from the left ventricle. . Mitral stenosis almost always results from rheumatic fever, a childhood illness that sometimes occurs after untreated strep throat or scarlet fever (see Bacterial Infections : Rheumatic Fever ).
When the valve has narrowed to less than 1.5 cm2 (normal, 4–6 cm2), the left atrial pressure must rise to maintain normal flow across the valve and a normal cardiac output. This results in a pressure difference between the left atrium and left ventricle during diastole. The pressure gradient and the length of the diastolic murmur reflect the severity of mitral stenosis; they persist throughout diastole when the lesion is severe or when the ventricular rate is rapid.
In mild cases, left atrial pressure and cardiac output may be essentially normal and the patient asymptomatic, but in moderate stenosis (valve area < 1.5 cm2)—especially with tachycardia, which shortens diastole and increases mitral flow rate—dyspnea and fatigue appear as the left atrial pressure rises. With severe stenosis, the left atrial pressure is high enough to produce pulmonary venous congestion at rest and reduce cardiac output, with resulting dyspnea, fatigue, and right heart failure. Recumbency at night further increases the pulmonary blood volume, causing orthopnea and paroxysmal nocturnal dyspnea. Severe pulmonary congestion may also be initiated by any acute respiratory infection, excessive salt and fluid intake, endocarditis, or recurrence of rheumatic carditis. As a result of long-standing pulmonary venous hypertension, anastomoses develop between the pulmonary and bronchial veins in the form of bronchial submucosal varices. These often rupture, producing mild or severe hemoptysis. In a few patients, the pulmonary arterioles become narrowed; this greatly increases the pulmonary artery pressure and accelerates the development of right ventricular hypertrophy and failure. These patients have relatively little dyspnea but experience fatigue on exertion.
Mitral stenosis can also be present at birth (congenital). Infants born with the disorder rarely live beyond age 2, unless they have surgery Typically, when rheumatic fever is the cause of mitral stenosis, the mitral valve cusps are partially fused together. . It is narrowed ('stenosed') when it is open. . The walls of the left atrium then become thickened (hypertrophied) and the atrium enlarges (dilates). These thrombi embolize in 20% of patients. The history of rheumatic fever may or may not be elicited systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), atrial myxoma, malignant carcinoid
Cause of Mitral Stenosis
Here are the list of the possible cause of Mitral Stenosis :
Symptoms of Mitral Stenosis
Some sign and symptoms related to Mitral Stenosis :
Treatment of Misitral Stenos
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