Mitral Stenosis- Clinical Features And Treatment

Causes: Rheumatic heart disease is the most frequent cause. The mitral valve is most frequently affected. Chordae tendineae or valve calculus. Congenital mitral stenosis; thickening, calcification, and inflammation of the valves in rheumatic heart disease cause the margins to adhere and obliterate the commissures, limiting the aperture. Rheumatic heart disease takes ten years to progress to mitral stenosis.

Pathophysiology of Mitral Stenosis

A rise in left atrial pressure that may result in arterial dilatation hypertrophy; A decrease in the diastolic flow from the left atrium to the left ventricle. Pulmonary artery hypertension results from back pressure in the pulmonary veins, which causes pulmonary congestion and reflex vasoconstriction to prevent pulmonary edema. 

The right ventricle will dilate if there is an increased strain on it. Tricuspid regurgitation will result from that, raising arterial pressure. Failure of the right heart will result from this.  Arterial fibrillation will occur following left artery dilation. There will be blood stasis in the left atrium once more. 

 A thrombus may form in the left atrium, which may cause the systemic vessels to get emboldened. Less blood will flow from the left atrium into the left ventricle when there is less arterial kick. Additionally, the cardiac output will drop. 

Clinical Features

For many years, the patient won't have any symptoms. When symptoms do occur, they are either caused by decreased forward flow or by back pressure. The patient may exhibit signs of exhaustion and dyspnea with effort. Pulmonary congestion symptoms are possible-.
Cough, hemoptysis, and dyspnea.

Signs and symptoms related to thromboembolism.-  Stroke in the head and neck, Mesenteric ischemia; ischemia in lower extremities. Right heart failure may cause a higher JVP upon inspection. Right ventricular heave may occur as a result of right ventricular hypertrophy. 

Immediately following the second heart sound on auscultation, an opening snap is audible. The first heart sound may be a strong tapping sound because reverse occurs when the valve shuts. Mid-diastolic rumbling murmur with pre-systolic accentuation that is low in pitch.
Graham steel murmur can occur as a result of pulmonary hypertension.

Investigations

ECG: Widening broad P wave; signs of atrial fibrillation may be present.  Deviation on the right axis. Tall QRS complexes in the leads of the right ventricle (V1-3). 

On x-ray of the chest -  An enlarged left atrium, a noticeable pulmonary artery, and the potential for Kerley's line to be present. Color flow echoes Doppler is a study that confirms findings. The degree of wall morphology and stenosis are visible. These are what the transthoracic echo will display. A transoesophageal echocardiogram is a more effective way to detect atrial thrombus.

Mitral Stenosis

• Mild mitral stenosis - Mitral valve area involved is less than 2 cm^2.
• Mitral valve area involved 1.5-2 cm² – moderate mitral stenosis.
• Mitral valve area involved < 1.5 cm² - severe mitral stenosis.
• Mitral valve area involved < 1 cm² - severe mitral stenosis.

Patients over 40 have coronary angiography. Cardiac MRI: performed in depth about structure and function.  Left atrial and pulmonary artery pressures are measured via right cardiac catheterization. 

Wilkins Score

The Wilkins score can be used to determine whether a patient is a good candidate for a percutaneous balloon mitral commissurotomy.
If the score is less than 8, choose PBMC. Proceed with surgery if > 8.

Treatment

Anticoagulation is a crucial part of medical treatment, and its decision is based on the CHADS2 score or CHADS2VASc score. Take diuretics to relieve congestion in the lungs. Use beta blockers and digoxin for arrhythmia.

Intervention Options

• Percutaneous balloon commissurotomy.
• Open commissurotomy.
• Mitral valve repair.
• Mitral valve replacement.

Indications For Intervention

Severe MS patients exhibiting symptoms, i.e., mitral valve area less than 1.5 cm2.  If a patient is asymptomatic but has very severe MS <1 cm2 or severe MS < 1.5 cm2 together with new-onset atrial fibrillation, intervention is required. Heart surgery is performed on asymptomatic individuals with moderate or severe multiple sclerosis for an unspecified cause.

Percutaneous Balloon Mitral Commissurotomy

Indication: minimal calcification, scarring, or fusion of the subvalvular apparatus in mobile, noncalcified leaflets; Wilkins's score should be less than 8. A commissural fusion may occur- 

Contraindication - Moderate to severe MR, MV calcification, or left atrial thrombus appearance. The femoral vein can enter the right atrium via the transseptal opening and exit into the left atrium in the antegrade route.

Dilate and inflate the balloon after inserting the catheter into the left ventricle and pulling it up into the mitral valve. In the mitral valve area, dilate the balloon. Follow the retrograde path, passing through the aorta into the left ventricle and then entering the left atrium through the mitral volume. 

Open Mitral Commissurotomy

 This is a rare and less desirable alternative.  It serves as the main surgical repair method.  The fact that the patient is placed on CPB and has induced cardioplegia makes it unusual and unfavorable.  Fused commissure division through surgery.

Surgery             

The recommended procedure is replacement of the mitral valve.
Patients with severe symptoms who are not candidates for PBNC may consider replacement of the mitral valve.  Patients with rheumatic heart illness will likely need mitral valve replacement instead of PBNC due to a significantly calcified valve.

Also Read: Knowing Venous Diseases and How to Treat Them

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