mitral stenosis Flashcards
what is mitral stenosis
Obstruction of LV inflow that prevents proper filling during diastole.
4 causes of mitral stenosis
Rheumatic heart disease
Infective endocarditis
Mitral annular calcification
Congenital
how does rheumatic heart disease cause mitral stenosis
Caused by rheumatic fever from group A beta-haemolytic strep
e.g. s. pyogenes
risk factors for mitral stenosis
History of rheumatic fever
Untreated streptococcus infections
pathology of mitral stenosis
- Thickening and immobility of valve leads to obstruction of blood flow from LA to LV 🡪 increased LA pressure, pulmonary hypertension and right heart dysfunction
- AF is common due to elevation of LA pressure and dilatation
Thrombus may form in the dilated atrium and give rise to systemic emboli e.g. the brain causing a stroke - Chronically elevated LA pressure leads to an increase in pulmonary pressure and pulmonary oedema
symptoms of mitral stenosis
- Progressive exertional dyspnoea
- Cough productive of blood-tinged sputum
- Haemoptysis – coughing up blood due to rupture of bronchial vessels due to elevated pulmonary pressure
- Right HF
- Fatigue
- Weakness
- Abdominal/lower leg swelling
- Palpitations – due to AF
- Chest pain
signs of mitral stenosis
- Mitral facies or malar flushes on cheek
- Low volume pulse which may become irregular
- Tapping, non-displaced apex beat
- Heart sounds
what causes mitral facies and malar flushes
when MS is severe, there is vasoconstriction due to decreased CO which results in pinkish-purple patches on the cheeks
what causes tapping non displaced apex beat
due to combination of palpable first heart sound and LV backward displacement produced by an enlarging RV
what heart sounds can you hear with mitral stenosis
Loud first heart sound at apex
The presence of a loud second heart sound, parasternal heave, elevated JVP, ascites and peripheral oedema indicate that pulmonary hypertension inducing right ventricular overload has developed
Diastolic murmur – heard when blood flows over a valve
Low-pitched diastolic rumble at apex
Heard best when patient is lying on left side with help expiration
investigations for mitral stenosis
echocardiogram
chest x ray
ecg
what does chest x ray show
LA enlargement, pulmonary hypertension and sometimes a calcified mitral valve
what does ECG show
AF and LA enlargement
treatment for mitral stenosis
Rate control if patient has AF – beta blockers, digoxin
Anticoagulation with warfarin for AF patients to prevent clot formation and embolisation
Diuretics for heart failure
Percutaneous mitral balloon valvotomy – access to mitral valve obtained via catheterisation through the femoral vein, RA and interatrial septum and a balloon is inflated to open the commisures
