Mitral valve regurgitation

Question 1

Anatomy of the mitral valve, what occurs during systole

Answer 1

• mitral valve has 2 leaflets: anterior and posterior leaflet
• during systole, high pressure is generated in the ventricles, and papillary muscles and CT chord tendinae (heart strings) keep the valve from prolapsing (falling back) in the atrium -> AV valves close (corresponding to S1)

Question 2

What is mitral valve regurgitation ?

Answer 2

• blood from the ventricle going back to the left atrium, because the mitral valve is not properly closed

Question 3

Mitral valve regurgitation: causes

Answer 3

• Mitral valve prolapse (most common)
• Heart attack: causing damage to papillary muscles
• LHF -> ventricular dilation -> mitral valve regurgitation.
• Rheumatic fever: inflammatory disease affecting the heart tissue -> leads to chronic rheumatic heart disease -> leads to leaflet fibrosis: make a hole letting blood coming in

Question 4

Mitral valve prolapse: C

Answer 4

• myxomatous degeneration: weakened CT of the leaflets, due to Marfan syndrome and Ehlers-Danlos syndrome

Question 5

Mitral valve prolapse: Signs and symptoms

Answer 5

• usually asymptomatic
• heart murmur: mid-systolic click, followed by systolic murmur (not always). Late systolic murmur
  Mid-systolic click results from the leaflet folding in the atrium and getting suddenly stopped by the chordae tendineae.
  Murmur results from the blood going in the left atrium.

Question 6

Mitral valve prolapse murmur characteristics

Answer 6

• when patient squats down -> click comes later (bigger volume in ventricle because in increased preload, so takes longer time) and the murmur is shorter
• when patient stands or do a Valsalva maneuver -> click come sooner and murmur last longer.

Question 7

Mitral valve regurgitation: Signs and symptoms

Answer 7

• holosystolic murmur: murmur lasting the whole systolic time
• pulmonary oedema
• fatigue
• dyspnea
• orthopnea

Question 8

Mitral valve regurgitation: complications

Answer 8

• can cause LHF (the other way around). Because, with mitral valve regurgitation, every time the left ventricle contracts, some blood goes to the left atrium -> which then goes back to the left ventricle (increased preload) -> both ventricle and atrium experiences volume overload -> left ventricle hypertrophy -> works for a while, then becomes LHF

Question 9

Mitral valve regurgitation: Diagnosis

Answer 9

• auscultation: Holosystolic (pansystolic) murmur, mid-systolic click + systolic murmur (for mitral valve prolapse)
• ECG
• CXR
• TTE: transthoracic echocardiogram

Question 10

Mitral valve regurgitation: Prognosis

Answer 10

• poor in symptomatic patients, 33% survival at 8 years without surgical intervention

Question 11

Mitral valve regurgitation: T

Answer 11

• Medical support: while waiting for surgery: ACEi, diuretics, digoxin/BB, anticoagulants
• Mitral valve repair/replacement