Mitral Stenosis

Overview

Overview Mitral stenosis causes an obstruction to blood flow from the left atrium to left ventricle usually as a result of rheumatic heart disease. The stenosis results in increased pressure in the left atrium, pulmonary vasculature and right side of heart. Mitral valve disease is a frequent cause of heart failure and death.

Epidemiology

Signs and Symptoms

  • Exertional dyspnoea
  • Decreased excercise tolerance
  • Haemoptysis
  • Chest pain
  • Fatigue
  • History of rheumatic fever
  • Malar flush
  • Signs of right-sided heart failure
    • ascites
    • raised JVP
    • peripheral oedema
  • Thromboembolic event "Stroke"
  • Hoarseness (recurrent laryngeal nerve compressed)
  • Dysphagia (esophagus compressed)

Cardiovascular Examination

  • Malar flush
  • Pulse
    • Weak pulse due to reduced strove volume
    • Atrial fibrillation
  • Left parasternal heave (from right ventricular hypertrophy)
  • Auscultation - Mitral valve (Apex - left 5th intercostal space mid-clavicular)
    • Pre systolic murmur precedes S1, a result of increase blood flow from atrial contraction
    • Opening snap of the mitral valve following S2 (closure of the aortic and pulmonic valves) is the opening of the stenotic mitral valve (SNAP)
    • Long murmur during Diastole (longer in chronic mitral stenosis)
    • Low-pitched diastolic rumble that is most prominent at the apex.
Side note Early diastolic murmur (on inspiration) due to pulmonary regurgitation from pulmonary hypertension (Graham Steell murmur) may be heard rarely.

 

Risk Factors

  • Streptococcal infection
  • Ergot medications
  • Serotogenic medications
  • SLE
  • Amylodoisis

Differential Diagnosis

Symptoms and signs similar to mitral stenosis

  • left atrial myxoma
  • prosthetic valve obstruction
  • Cor tratriatum

Investigations

  • ECG
    • Atrial fibrillation
    • Left atrial enlargement - P mitrale
    • Right ventricular hypertrophy - Right axis deviation
  • Chest X-ray
    • Straight or convex L heart border
    • Double shadow of LA behind RA
    • Splaying of carina
    • Dilated upper lobe veins
    • Prominent pulmonary conus
    • Pulmonary haemosiderosis
  • Trans-thoracic echocardiography
  • Transoesophageal echocardiography
  • Cardiac catherization

Diagnosis

Echocardiography — A transthoracic echocardiogram is indicated in patients with signs or symptoms of MS to establish the diagnosis, quantify the hemodynamic severity determine the etiology, and assess concomitant valve disease.

Aetiology

  • Rheumatic fever leading to rheumatic heart disease (95% of cases)
  • Congenital

Pathophysiology

Management

Medication - Preload reduction

  • No treatment generally required if asymptomatic but monitoring is important
  • Diuretics and sodium
Think ACE inhibitors have no role as the ventricles are normal

Surgery

  • Balloon valvotomy
    • moderate to severe symptomatic disease
  • Diuretic
  • Valve replacement or repair
    • Mechanical
    • Bioprosethetic

Complications and Prognosis

Complications

  • Atrial Fibrillation
  • Stroke
  • Warfarin-induced haemorrhage
  • Systemic Embolism - due to thrombus formation in the right atrium
  • Infective endocarditis
  • Functional tricuspid reguritation

Prognosis

  • With continuous monitoring and ppropriate treatment prognosis is excellent
  • Death from Mitral stenosis is oftne due to progressive right-sided heart failure and/or pulmonary edema

Valvular Heart Disease

  • Endocarditis
  • Aortic Valve Disease
  • Mitral Valve Disease
    • Mitral Stenosis
    • Mitral Regurgitation
  • Pulmonary Valve Disease
  • Tricuspid Valve Disease
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