[6] Mitral Stenosis Flashcards
What happens when the mitral valve area goes below 2cm2?
The valve causes an impediment of the flow of blood into the left ventricle, causing a pressure gradient across the mitral valve
What causes the pressure gradient caused by mitral stenosis to increase?
- Increased heart rate
- Increased cardiac output
What happens as the pressure gradient in mitral stenosis increases?
The amount of time necessary to fill the left ventricle with blood increases, until eventually the left ventricle requires atrial kick to fill with blood
What happens when the heart rate goes above a certain point in mitral stenosis?
The diastolic filling period is insufficient to fill the ventricle with blood, and so pressure builds up in the left atrium
What does the pressure build up in the left atrium in mitral stenosis cause?
Pulmonary congestion
What are the causes of mitral stenosis?
- Rheumatic fever
- Calcium deposits
- Congenital defects
- Lupus
- Radiation to chest
What are the symptoms of mitral valve stenosis?
- Shortness of breath, especially with exertion or when lying down
- Fatigue, especially during increased physical activity
- Oedema
- Palpitations
- Dizziness or fainting
- Haemoptysis
- Angina
What is involved in the diagnosis of mitral valve stenosis?
- Examination
- ECG
- Chest x-ray
- Echocardiography
- Cardiac catheterisation
What are the examination findings of aortic stenosis?
- Malar flush
- Atrial fibrillation-characteristic pulse
- May be raised JVP
- Tapping apex beat
- Might have right ventricular heave
What might the ECG show in aortic stenosis?
- Atrial fibrillation
- P-mitrale - the presence of broad, notched P waves in lead II
What is P-mitrale a sign of?
Atrial enlargement
What might the CXR show in mitral stenosis?
- Left atrial enlargement (double shadow in right cardiac silhouette)
- Pulmonary oedema
- Mitral valve calcification
What are the indications for cardiac catheterisation in mitral valve stenosis?
- Previous valvotomy
- Signs of other valve disease
- Angina
- Severe pulmonary hypertension
- Calcified mitral valve
What are the options in the management of mitral valve stenosis?
- Management of atrial fibrillation, including rate control and anticoagulation
- Percutaneous balloon mitral valvuoplasty
- Mitral valve commissurotomy
- Mitral valve replacement
What are the roles for medical therapy in mitral valve stenosis?
- Alleviate associated dyspnoea
- Improve exercise tolerance
- Anticoagulation
What drugs can be used to alleviate associated dyspnoea in mitral valve stenosis?
Diuretics or long-acting nitrates
What can be used to improve exercise tolerance in mitral valve stenosis?
- Beta-blockers
- Heart rate-regulating calcium channel blockers
When is anticoagulant therapy indicated in mitral stenosis?
- In patients wtih either pernament or paroxysmal atrial fibrillation
- When there has been a prior embolism, or a thrombus is present in the left atrium
Which patients should be considered for a percutaneous balloon mitral valvuoplasty?
Symptomatic patients with severe mitral stenosis, or those with pulmonary hypertension
What happens in a percutaneous balloon mitral valvuloplasty?
A catheter is placed into an artery in the arm or groin, and guided to the stenotic valve. Once in position, a balloon is inflated to widen the valve, improving blood flow. The balloon is then deflated and removed
What is the limitation of percutaneous balloon mitral valvuloplasty?
The procedure may have to be repeated over time, or may not be successful and symptoms persist
What should be done if a percutaneous balloon mitral valvuloplasty is not successful and symptoms persist?
Surgery should be considered early, unless there are definite contraindications
What is commissurotomy?
Open heart surgery, in whcih calcium deposits and other scar tissue is removed from the valve
When might commissurotomy need repeating?
If mitral valve stenosis reoccurs
