MR + MS + Murmurs Flashcards
What is mitral regurgitation?
Mitral regurgitation (MR) occurs when blood leaks back through the mitral valve on systole
It is the second most common valve disease after aortic stenosis
How can MR lead to HF?
- Degree of regurgitation becomes more severe :. oxygen demands exceed what the heart can supply :. the myocardium can thicken over time.
- Benign initially ==> increasingly fatigued as a thicker myometrium becomes less efficient :. irreversible heart failure.
What are the risk factors for MR?
- Female sex
- Lower body mass
- Age
- Renal dysfunction
- Prior myocardial infarction
- Prior mitral stenosis or valve prolapse
- Collagen disorders e.g. Marfan’s Syndrome and Ehlers-Danlos syndrome
What are causes of MR?
- Following coronary artery disease or post-MI: if the papillary muscles or chordae tendinae are affected by a cardiac insult
- Mitral valve prolapse: Leaflets of the mitral valve is deformed :. backflow. Most patients with this have a trivial degree of mitral regurgitation.
- Infective endocarditis: Vegetations colonising on mitral valve
- Rheumatic fever: Uncommon in developed countries, rheumatic fever can cause inflammation of the valves
- Congenital
What are symptoms of MR?
- Most patients with MR are asymptomatic, and patients suffering from mild to moderate MR may stay largely asymptomatic indefinitely.
- Symptoms tend to be due to failure of the left ventricle, arrhythmias or pulmonary hypertension.
- This may present as fatigue, shortness of breath and oedema
What are signs of MR?
- Pansystolic murmur described as “blowing”
- Heard best at the apex and radiating into the axilla
- S1 may be quiet as a result of incomplete closure of the valve
- Severe MR may cause a widely split S2
What investigations are needed for MR?
- ECG: broad P wave, indicative of atrial enlargement
- CXR: Cardiomegaly with an enlarged left atrium and ventricle
- ECHO: crucial to diagnosis and assess severity
What is the management for MR?
-
Acute cases:
- nitrates
- diuretics
- positive inotropes
- an intra-aortic balloon pump to increase cardiac output
- Heart failure: ACE inhibitors may be considered along with beta-blockers and spironolactone
- Acute, severe regurgitation = surgery
- The evidence for repair over replacement is strong in degenerative regurgitation, and is demonstrated through lower mortality and higher survival rates
- When not possible, valve replacement with either an artificial valve or a pig valve is considered
What is the cause of mitral stenosis?
- Rheumatic fever!!!!
- Mucopolysaccharidoses
- Carcinoid
- Endocardial fibroelastosis
What are the features of mitral stenosis?
- Mid-late diastolic murmur (best heard in expiration)
- Loud S1, opening snap
- Low volume pulse
- Malar flush
- Atrial fibrillation
What are the features of severe MS?
- Length of murmur increases
- Opening snap becomes closer to S2
What do investigations of MS show?
Chest x-ray: left atrial enlargement
ECHO: the normal cross sectional area of the mitral valve is 4-6 sq cm. A ‘tight’ mitral stenosis implies a cross sectional area of < 1 sq cm
What are associations of mitral valve prolapse?
Associations:
- Congenital heart disease: PDA, ASD
- Cardiomyopathy
- Turner’s syndrome
- Marfan’s syndrome, Fragile X
- Osteogenesis imperfecta
- Pseudoxanthoma elasticum
- Wolff-Parkinson White syndrome
- Long-QT syndrome
- Ehlers-Danlos Syndrome
- Polycystic kidney disease
What are the features of mitral valve prolapse?
- Atypical chest pain or palpitations
- Mid-systolic click (occurs later if patient squatting)
- Late systolic murmur (longer if patient standing)
- Complications: mitral regurgitation, arrhythmias (including long QT), emboli, sudden death
When do you hear an ejection systolic murmur?
- Aortic stenosis
- Pulmonary stenosis, hypertrophic obstructive cardiomyopathy
- Atrial septal defect, tetralogy of Fallot
Give a summary of all murmurs
