Mitral valve stenosis Flashcards
What is it?
Narrowing of the valve < 2cm causing blood flow obstruction from LA to LV
Why does heart dilate?
Because the heart muscle is weakened and cannot pump effectively, commonly due o ischaemia (less coronary blood flow)
What are 3 main causes of mitral stenosis?
Rheumatic heart disease
Congenital mitral stenosis
Systemic conditions
What are the symptoms of mitral stenosis?
Pul. oedema Haemoptysis Systemic embolisation Infective endocarditis Hoarseness - compression of L recurrent laryngeal Dyspnoea Chest pain
What are signs on clinical examination?
Mitral facies: rosy cheeks due to low cardiac output and perfusion Normal pulse JVP - prominent a wave Tapping apex beat and diastolic thrill RV heave
How does MS lead to low Cardiac output?
Low LV EDV -> low preload -> low SV -> low CO
What investigations should be carried out?
ECG Cardiac catheterisation CXR ECHO Cardiac MRI
What are medical treatments for mitral stenosis?
Diuretics
Lower Na intake (for HPT)
Sinus rhythm restoration
Anticoagulation (for AF)
What happens to CO, SV and HR?
EDV is lower in LV therefore preload decreases and SV lowers.
HR increases to compensate and try to deliver more blood -> tachycardia - which also decrease the diastolic filling time
Overall decrease in CO
How does tachycardia in M stenosis cause AF?
The stretching and enlargement of LA can cause heart rhythm irregularity in which the upper chambers of heart beat chaotically and too quickly
What are 2 systemic conditions which causes mitral stenosis?
Systemic lupus erythematosus
Rheumatoid arthritis
What happens to the A-V pressure gradient in mitral stenosis?
Increase
What happens to the LA pressure in mitral stenosis?
Increase as blood builds up in the chamber
What happens to the pulmonary venous and capillary pressure in mitral stenosis?
Increases, as blood, instead of going in to the ventricle, flows back in to the pulmonary circulation
What happens to pulmonary vascular resistance?
Increase
What happens to pulmonary arterial pressure and what can it cause?
PaP increases and pulmonary HPT develops
What happens to the right side of the heart?
Dilatation because of tricuspid regurgitation and pulmonary regurgitation
What happens to LV pressure and systolic function?
LV pressure and systolic function normal
What does the mitral stenosis severity depend on?
Trans-valvular pressure gradient
Trans-valvular flow rate (increase in HR or CO)
When might heart rate increase, causing the severity of mitral stenosis to increase?
Exercise
Acute illness
Pregnancy
Atrial fibrillation
What will cause dyspnoea in mitral stenosis?
On mild exertion
From pulmonary oedema
Why might mitral stenosis cause haemoptysis?
When there is rupture of thin-walled veins in the lungs from increased pressure
Why might mitral stenosis cause systemic emboli? And what can this lead to?
As left atrial and left auricle enlargement can lead to emboli which can lodge in the carotid artery, causing a stroke
Why might mitral stenosis cause hoarsness of voice?
Compression of the L recurrent laryngeal nerve
What does an elevated a wave of the JVP indicate?
Resistance to right atrial emptying
Why might a rv heace be palpable in mitral stenosis?
Increased pulmonary pressure causes RV hypertrophy
What will be seen on a CXR with mitral stenosis?
LA enlargement
What will be seen on an ECHO with mitral stenosis?
Thickening and scarring of leaflets
Fusion of commissures
Explain why it’s a diastolic thrill that is heard?
During diastole, the mitral valve is open to fill the ventricle, so stenosis of that valve causes a murmur heard after S2 heart sound
What will be seen on an ECG of mitral stenosis?
RVH
P>0.12sec
What are interventional treatments for mitral stenosis?
Balloon valvotomy - widens valve
Mitral V. replacement
