Mitral valve disease (CVS) Flashcards
Define mitral stenosis
This is the narrowing of the mitral valve, reducing blood flow to the left ventricle. This leads to increased pressure in LA, pulm vasculature, and right heart
What is the main cause of mitral stenosis?
Rheumatic fever
What is the pathophysiology of mitral stenosis?
Normally, mitral valve opens during diastole to allow left ventricular filling.
In mitral stenosis, the thickened scarred mitral valve reduces the bloodflow through the valve into the LV in diastole. This leads to a reduced end-diastolic volume in the LV and increases the vol of blood in the LA and this leads to atrial dilatation (predisposing to atrial fibrillation), pulmonary congestion and ultimately right heart failure.
What are the rarer causes of mitral stenosis?
Mitral annular calcification (age related), Congenital MS (rare), Mucopolysaccharidosis, carcinoid, systemic disease like SLE or rheumatic arthritis
These are seen in developed countries
What are the risk factors for mitral stenosis?
Ageing, radiation, strep a, other causes
What are differentials of mitral stenosis?
Mitral regurg, Aortic stenosis, Left atrial myxoma
What is the aetiology of rheumatic heart disease causing mitral stenosis (simple)?
The body produces antibodies to target the streptococcal antigens that occur in rheumatic fever. These antibodies also attack valvular tissue (autoimmune molecular mimicry) leading to valvular disease.
What are the symptoms of mitral stenosis?
Typically asymptomatic until advanced stenosis
SOB, Haemoptysis, malar flush, palpitations (if AFib happens), chest pain
What are the clinical signs of mitral stenosis?
- Irregularly irregular pulse (AF)
- Elevated JVP
- Right ventricular heave
- Inspiratory crepitations (pulmonary oedema) and other signs of right HF
- Low volume pulse
- Loud S1/S2
- Mid-to-late diastolic murmur
- low pitch rumble
- most prominent at apex
- loudest on expiration
- heard best on pt lying left and
using bell
- Early diastolic murmur (only if pulmonary regurgitation is present, secondary to pulmonary HTN)
What are the investigations for mitral stenosis?
Echo - this makes the diagnosis as we see degree of stenosis and impairment of vent filling
CXR - may show pulm oedema and LA enlargement
ECG - p mitrale, right vent hypertrophy, right axis deviation, Afib
Cardiac MRI
When do symptoms start with mitral stenosis area wise?
Typically when falls below 1.5cm^2
What is the management of asymptomatic mitral stenosis?
Observe/monitor - regular follow up echocardiograms to assess progression
What is the management of mitral stenosis with the complication of Afib?
Anticoagulation - warfarin for mod-severe MS. Maybe consider DOACs for mild MS.
What is the management of symptomatic mitral stenosis?
- Balloon valvuloplasty (if valve is pliable and not calcified)
- Percutaneous mitral balloon valvotomy (for moderate)
- Open valve surgery: Either a Commissurotomy or Valve replacement (for severe disease who are not too high risk for surgery, but not candidates for percutaneous)
What are the complications of mitral stenosis?
Afib, pulmonary hypertension, dilated left atrium
Define mitral regurgitation
Backflow of blood into the left atrium during systole due to an incompetent mitral valve
It is common.
What are the common causes of mitral regurg?
Mitral valve prolapse
Degenerative valve disease (age)
MI with secondary papillary muscle rupture
Infective endocarditis
Rheumatic heart disease
What are the differentials of mitral regurg?
Aortic stenosis, tricuspid regurg, aortic regurg
What are the clinical features of acute mitral regurg?
This is an emergency.
SOB, exertional dyspnea, fatigue, weakness, cardiogenic shock, pulm oedema
What are the clinical symptoms of chronic mitral regurg?
Mild to moderature - asymptomatic until Left HF leading to pulmonary hypertension or symptomatic atrial fibrillation (AF)
Then we see symptoms such as exertional dyspnea and fatigue occuring due to the pulm hypertension.
What are the clinical signs of mitral regurg?
- Pansystolic ‘blowing’ murmur
- Loudest at apex
- Radiates to axilla
- Louder on expiration
- Louder on rolling to left
- Absent / quiet S1
- IF pt in decompensated HF
- Bi-basal lung crepitations
- Raised JVP
- S3 / S4
- Peripheral / sacral oedema
What are the investigations for sus mitral regurg?
Echo - diagnostic/definitive
ECG - broad P wave/p mitrale due to LA enlargement
CXR - pulm oedema and LA enlargement
What is the management of acute mitral regurg incl if complications?
This is an emergency with often shock and flash pulm oedema.
Nitrates, diuretics, positive inotropes, and an intra aortic balloon
If has HF - consider ACEi and BB
If acute and v severe -> surgery (repair>replacement)
What are the complications of mitral regurg?
HF
Afib leading to thromboembolism
What is the management of chronic mitral regurg?
Most chronic cases remain asymptomatic and stable and may not require treatment at all.
If has asymptomatic MR they should undergo regular follow-up echocardiography.
