Cardiology: Valvular Heart Disease: MS & MR Flashcards
What rhythm is shown in this CXR? [1]
Afib
What does this mitral valve ECHO show? [1]
Mitral regurg.
Why is the posterior mitral valve leaflet vulnerable to posterior MIs? [1]
posterior mitral valve leaflet is supplied by a branch of the RCA
Describe different causes of mitral regurgitation [++]
Mitral valve leaflet disease
- Mitral valve prolapse (leaflets prolapse during systole:
- Rheumatic disease
- Infective endocarditis: due to perforated leaflet; valve destruction
Subvalvar disease
- Chordal rupture (chordae tendinae)
- Papillary muscle dysfunction (usually ischaemic)
- Papillary muscle rupture
Functional MR
- Dilated Cardiomyopathy & LV dilatation
- Post MI: LV impairment & dilatation
- HOCM
Chronic atrial fibrillation leading to dilated left atrium & dilated annulus
Which chambers does the mitral valve sit between? [2]
What does each leaflet of mitral valve attach to? [1]
What do each of ^ attach to? [1]
Left atrium and ventricle
Leaflets attach to chordae tendinae
Chordae tendinae attach to papillary muscles, which attach to the ventricular wall
Describe the pathophysiology of acute MR [5]
Acute MR: fast and significant changes to flow without time for any adaptation or remodelling to occur:
- new regurgitation causes increased pressure within a non-compliant left atrium
- As result of the lack of compliance this is reflected in rises in pressure in the pulmonary circulation
- Ejection fraction falls as blood is ejected back across the regurgitant valve instead of forward though the aortic valve
- Tachycardia may occur to try and compensate
- Often fails and leads to cardiogenic shock
Describe the pathophysiology of chronic MR [2]
Chronic MR: Gradual worsening of regurgitation fraction that initally allows for compensation
- Compenstated state: left atria and ventricle dilate: LV undergoes eccentric hypertrophy and maintain a larger SV and therefore EF. The compliant and dilated left atrium prevents rises in pulmonary pressures
- Decompanstated state: eventually such changes cannot maintain normal cardiac function and the remodelling becomes increasingly pathological. The heart fails, ejection fraction falls and a backlog of blood waiting to be pumped through the left side of the heart occurs; pulmonary pressures rises and get congestive heart failure
What are the symptoms of MR? [4]
SOB & dysopnoea (to increase in left atrial pressure)
Fatigue
Signs of RHF (ankle swelling; distended abdomen)
Palpitations due to afib
Describe the signs of MR [6]
- Pan systolic, high pitched whistling murmur (due to high velocity of blood flow through the leaky valve)
- Murmur radiates to left axilla
- Soft S1: due to incomplete closure.
- 3rd heart sound may be present due to rapid filling of a dilated ventricle.
- Thrill on palpitation
- Signs of HF
- Signs of pulmonary oedema
- Afib
Which CT disorders can lead to MR? [2]
Ehlers-Danlos syndrome
Marfan syndrome
Which is the most associated with rheumatic fever?
Mitral regurgitation
Mitral stenosis
Atrial regurgitation
Atrial stenosis
Which is the most associated with rheumatic fever?
Mitral regurgitation
Mitral stenosis
Atrial regurgitation
Atrial stenosis
What is the investigation of choice for MR? [1]
ECHO
Allows visualisation of the incompetent valve and can confirm the underlying aetiology. Left atrial and ventricular enlargement may be seen in chronic MR.
What CXR findings would indicate MR? [2]
Left atrial and ventricular enlargement
Acute MR: pulmonary oedema (due to increased back pressure)
Dilated left atrium and left ventricle in a patient with chronic MR
What is a tell tale sign of left atrial enlargement on CXR? [1]
double-density sign, also known as the double right heart border
Normally the left atrium is located posteriorly and only the atrial appendage component is visible. But left atria becomes englarged enlarged, the right aspect may become visible as an extra shadow next to the right atria
If the double density sign is present on a CXR, what measurement can be taken to confirm left atrial enlargement? [1]
Olbique left atrial measurement: outer edge of atrium to midpoint of left main bronchus: > 7 cm = LA enlargement
Acute MR is characterised by which two features? [2]
Patients with acute MR are normally profoundly unwell. Condition characterised by shock and flash pulmonary oedema
Which drug can be used to reduce afterload before acute MR surgery? [3]
- diuretics
- sodium nitroprusside
- positive inotropes: dobutamine
- intra-aortic balloon counterpulsation (helpes the by heart indirectly by decreasing the afterload but increases cardiac output)
Which drugs would you give for MR patients in HF? [3]
- ACE inhibitors
- beta-blockers
- spironolactone
When is surgery indicated for chronic MR patients?
Chronic MR:
-
asymptomatic & LVEF < 60%
OR - asymptomatic & LV end systolic diameter >40mm
- All symptomatic if fit for surgery
BMJ BP
What surgical treatment is used to treat MR? [2]
Surgical valve repair
Valve replacement (artificial / pigs valve)
Explain why MR can occur after CAD or post-MI? [1
Following coronary artery disease or post-MI: if the papillary muscles or chordae tendinae are affected by a cardiac insult, mitral valve disease may ensue as a result of damage to its supporting structures.