Valvular disease - Mitral Stenosis Flashcards
What is mitral stenosis?
https://www.youtube.com/watch?v=nY4aaBezu9o
Mitral stenosis is a narrowing of the mitral valve orifice, usually caused by rheumatic valvulitis producing fusion of the valve commissures and thickening of the valve leaflets.
What are causes of mitral stenosis?
- Rheumatic fever
- Congenital MS
- Systemic disease - SLE, RA
- Malignant Carcinoid
- Mucopolysaccharidoses
What is the normal surface area of the mitral valve?
4-6 cm2
What is classed as severe mitral stenosis?
<1 cm2
What happens to the left atrium in mitral stenosis?
In order that sufficient cardiac output will be maintained, the left atrial pressure increases and left atrial hypertrophy and dilatation occur
Why does pulmonary oedema occur in Mitral Stenosis?
Pulmonary venous, arterial and right heart pressures increase. The increase in pulmonary capillary pressure is followed by the development of pulmonary oedema
What can exacerbate pulmonary oedema in mitral stenosis?
Atral fibrillation
What are symptoms of mitral stenosis?
- Dyspnoea
- Fatigue
- Palpitations
- Chest pain
- Systemic emboli
- Haemoptysis
- Lower limb swelling
Why do individuals get dyspnoea in mitral stenosis?
A combination pulmonary venous hypertension and recurrent bronchitis
What causes palpitations and systemic emboli in mitral stenosis?
AF
Why is AF more likely to occur in mitral stenosis?
Larger left atrium is more predisposed to AF
Why can mitral stenosis cause haemoptysis?
Pulmonary hypertension, which leads to varices in the submucosa of the bronchial walls.
What are signs of mitral stenosis?
- Malar flush (Mitral faces)
- Low-volume pulse
- AF
- Tapping, non-displaced apex
- Loud S1
- Opening snap
- Rumbling diastolic murmur
- Graham Steel murmur
What causes the murmur heard in mitral stenosis?
Diastolic blood flow across a damaged, narrow valve - With the valve narrowed, the blood flow across it in diastole is turbulent and produces the characteristic murmur.
Where is mitral stenosis heard best?
Best heard with the bell of the stethoscope held lightly at the apex with the patient lying on the left side
When is the murmur of mitral stenosis heard?
Diastole
Why might you get a loud S1 in mitral stenosis?
Occurs if the mitral valve is pliable
Why might you get an opening snap in mitral stenosis?
The stenotic calcified valve tends to form a ‘dome’ shape during diastole, as the left ventricle attempts to suck blood into its cavity. Although initially mobile, the calcification of the valve will abruptly stop further movement, causing an opening snap
What is a Graham Steel murmur?
A high-pitched, early diastolic, blowing decrescendo murmur best heard in the pulmonary area of the praecordium on full inspiration. It is a pulmonary regurgitative murmur in the setting of pulmonary hypertension.
Pulmonary hypertension (usually above 55–60 mmHg) leads to increased pressure on the pulmonary valve and annulus. Dilatation of the annulus occurs and the valve becomes incompetent. The high-flow jet of blood across the incompetent valve creates the murmur.
Why do you get a tapping non-displaced apex in Mitral stenosis?
Reduced ventricular filling caused by stenosis over the mitral valve results in a shortened outward movement of the apex, which creates the short, sharp tapping quality.
Alternative theory - the stenosed valve provides an obstruction to blood flow into the left ventricle, resulting in elevated left atrial pressures which delay mitral valve closure. Instead of slowly gliding shut, the thickened leaflets are ‘slammed’ closed under higher pressure at the start of systole, resulting in a palpable S1.
How could you determine the severity of stenosis based on the murmur?
The longer the diastolic murmur, the more severe the stenosis. The opening snap also gets closer to S2 heart sound
What causes mitral faces?
This is a bilateral, cyanotic or dusky pink discoloration over the upper cheeks. It is due to low cardiac output with severe pulmonary hypertension leads to chronic hypoxaemia and skin vasodilatation.
What investigations would you do in someone with mitral stenosis?
- ECG
- CXR
- ECHO
- Cardiac MRI
What would you see on ECG in someone with mitral stenosis?
- AF
- P mitrale - if sinus rhythm
- Signs of RVH
What might you see on CXR in someone with mitral stenosis?
- Left atrial enlargement
- Pulmonary oedema
- Mitral valve calcification
How would you manage someone with mild mitral stenosis?
- Treat acute episodes of bornchitis
- Treat mild dyspnoea with diuretics
What is incredibly important to get under control when treating mtiral stenosis?
AF - need digoxin and anticoagulation
What options are available for surgical intervention for Mitral stenosis?
- Balloon valvuloplasty
- Open mitral valvotomy or replacement
What are complications of mitral valve stenosis?
- PHT
- Ambolic events
- Pressure of LA on local structures
- Infective endocarditis
What structures can be compressed by left atrial enlargement in mitral stenosis?
- Recurernt laryngeal nerve
- Oesophagus
What mnemonic could you use to remember the features of mitral stenosis?
MALAR PATCHES
- Malar flush
- AF
- Left heath failure
- Apex - tapping, undisplaced
- Right heart failure
- Palpitations
- Auscultation - loud S1 + opening snap, rumbling mid-diastolic murmur (patient on their left side and in expiration); Graham Steell murmur
- Thromboembolism
- Cachexia/Cyanosis/COPD or Chronic bronchitis-like scenario
- Haemoptysis, rupture of congested bronchioles/Hoarse voice
- Emboli (systemic)
- Syncope
