A. Mitral Valvular Stenosis

Mitral stenosis is narrowing of the mitral valvular. Most patients with valvular mitral stenosis asymptomatic for several years and may not have symptoms until the fourth or fifth decades of life.

The left atrium meets resistance as it attempts to pass valvular mitral and ejecting blood forward into left ventricle. Eventually the left atrium dilates and contractility decreases. Forward flow is decreased and fluid backs up into lungs. Increased volume in the lungs increases pressure in lungs developing congestive heart failure if not treated properly.




Causes of Valvular Mitral Stenosis :

1. The rheumatic heart disease is main trigger the mitral valve to become inflamed tissue then fibrinous occur, resulting in leaflet thickening and narrowing of the mitral valve.

2. Congenital abnormality causes the valve to thicken by fibrosis and calcification, obstructing blood flow.

3. Myxoma (noncancerous tumor in left atrium) obstructs the blood flow through the mitral valvular.

4. Blood clot reduces blood flow through the mitral valve.

5. Adverse effect of fenfluramine and phentermine diet drug combination causes the valve to thicken by fibrosis and calcification.





Signs and Symptoms of Valvular Mitral Stenosis


1. In severe mitral stenosis, on auscultation, there are four typical findings including: an accentuated S1, an opening diastolic snap, a mid-diastolic rumble noted best at the apex (in sinus rhythm, followed by presystolic accentuation), and an increased pulmonic S2 intensity associated with pulmonary.

2. Exertional dyspnea: the narrowing mitral valvular decreases blood filling into the ventricles. Decreased volume in ventricle decreases SV and CO. Supply does not meet demand,causing exertional dyspnea, congestive heart failure occur if not treated properly.

3. The mitral valve is narrowed, causing backward flow of volume from the left atrium into the lungs, resulting in exertional dyspnea.

4. Orthopnea, Atrial fibrillation.

5. Nocturnal dyspnea: when lying down, all the blood that pools in the extremities during the day returns to the heart. This causes more fluid in the lungs.





Diagnostic Test for Valvular Mitral stenosis

1. Echocardiography is used in the evaluation of mitral stenosis to : quantify the valve area and gradient, to quantify the degree of mitral insufficiency, to define the degree of left atrial enlargement, to assess mitral annular calcification, to assess pulmonary artery pressures and degree of pulmonary hypertension, to evaluate right- and left-sided ventricular function.
2. Electrocardiography (EKG): reveals left atrial enlargement, right ventricular hypertrophy, atrial fibrillation.
3. Chest radiography correlates with the degree of mitral stenosis.
4. Cardiac catheterization to determine location and extent of blockage, catheterization is used less in diagnosis of mitral stenosis as echocardiography techniques improve.




Treatment

1. Percutaneous Mitral Catheter Balloon Valvuloplasty.

2. Prevention of rheumatic fever, Oxygen: increases oxygenation.

3. Digoxin, lowsodium diet, diuretics, vasodilators, ACE inhibitors: treat left-sided heart failure.


4. Prophylactic antibiotics before and after surgery and dental care: prevent endocarditis.

5. Anticoagulants, Nitrates, Cardioversion: converts atrial fibrillation to sinus rhythm.

6. Percutaneous Mitral Catheter Balloon Valvuloplasty.

7. Percutaneous mitral catheter balloon valvuloplasty is an alternative, less invasive procedure than surgical treatment for mitral stenosis. Balloon valvuloplasty is performed in the cardiac catheterization laboratory by a cardiologist experienced with invasive techniques. A small balloon valvuloplasty catheter is introduced percutaneously at the femoral vein and passed into the right atrium. The catheter is then directed transseptally and positioned across the mitral valve.

8. Surgical Treatment. Surgical replacement of the mitral valve is required when there is severe mitral regurgitation coexisting with mitral stenosis. Although some valves with mitral stenosis may be repaired by open commissurotomy and reconstruction, heavily calcified rheumatic mitral valves often are beyond the point of repair. The usual prosthetic valve of choice in mitral stenosis is a mechanical prosthesis because patients already require life-long anticoagulation because of atrial fibrillation. For young women who wish to become pregnant, a bioprosthesis may be recommended.