Mitral valve disease (CV) Flashcards
What is mitral stenosis?
Narrowing of the mitral valve orifice, often caused by rheumatic valvulitis producing fusion of the valve commissures and thickening of the valve leaflets
Decreased cross-sectional area of the valve, impairing blood flow from LA–>LV
What is mitral stenosis most commonly due to?
Rheumatic heart disease (90% of cases)
What are some signs of rheumatic fever (main cause of mitral stenosis)? (2)
- prodromal illness
- erythema marginatum - annular (ring-like) erythematous rash affecting trunk and inner surfaces of arms and legs; rings are barely raised and non-pruritic
How do we treat rheumatic fever? (Main cause of mitral stenosis)
IM benzylpenicillin or oral penicillin V
How do the causes of mitral stenosis differ between countries?
- rheumatic fever is the main cause in low and middle-income countries
- mitral annular calcification is the main cause in high-income countries
What can mitral stenosis lead to?
- causes decreased filling of LV while simultaneously increasing LA pressure –> LA hypertrophy and dilation –> pulmonary congestion & oedema
- as disease progresses, pulmonary hypertension and right heart failure occur
What is mitral regurgitation?
Leakage of blood from LV –> LA due to incomplete closure of mitral valve during systole
How common is mitral regurgitation?
Second most common mitral disease after aortic stenosis
What is the difference between primary and secondary mitral regurgitation?
- primary MR - caused by direct involvement of valve leaflets
- secondary MR - caused by changes of LV leading to valvular incompetence
What are some causes of primary mitral regurgitation? (3)
- rheumatic fever - most common
- infective endocarditis
- mitral valve prolapse (young females)
What are some causes of secondary mitral regurgitation? (2)
- coronary artery disease (common post-MI due to papillary wall rupture)
- dilated cardiomyopathy
What is the most common cause of mitral regurgitation?
Rheumatic heart disease
(Others: infective endocarditis, mitral valve prolapse, papillary muscle rupture, annular calcification)
What can mitral regurgitation lead to?
- increased backflow of blood from LV–>LA increases pressure and results in pulmonary hypertension
- consequent atrial dilation increases risk of atrial fibrillation
What are some risk factors for secondary mitral valve disease? (2)
- collagen disorders - Marfan syndrome (fibrillin-1 mutation), Ehlers-Danlos syndrome
- collagen disorders characterised by widespread joint hypermobility along with skin changes indicated by striae
- polycystic kidney disease (associated with mitral valve prolapse and mitral regurgitation)
What are some clinical features of mitral stenosis? (10)
- dyspnoea
- orthopnoea
- paroxysmal nocturnal dyspnoea
- fatigue
- hoarseness - compression of recurrent laryngeal nerve by enlarged LA
- dysphagia - compression of oesophagus by enlarged LA
- haemoptysis
- malar flush
- palpitations (AF)
- symptoms of right HF in later stages
What may you hear on auscultation in mitral stenosis? (3)
- mid-diastolic murmur - best heard on expiration on left lateral side (left lateral decubitus)
- loud S1, opening snap –> pre-systolic accentuation
- severe MS - length of murmur increases + opening snap becomes closer to S2
What do you hear in severe mitral stenosis?
Length of murmur increases + opening snap becomes closer to S2
What might you see on examination in mitral stenosis? (10)
- malar flush
- neck vein distension
- peripheral cyanosis
- AF = irregularly irregular pulse
- parasternal heave (RVH secondary to pulmonary hypertension)
- mid-diastolic murmur (loudest in left lateral decubitus on expiration)
- loud S1 + opening snap
- Graham Steell murmur may occur
- evidence of pulmonary oedema on auscultation (if decompensated)
- ascites and peripheral oedema
