Prosthetic valves: aortic and mitral

Question 1

Prosthetic valves: aortic and mitral

Answer 1

This patient has recently been treated for dyspnoea/chest pain/syncope. Please examine his cardiovascular system.

Question 2

Clinical signs in prosthetic valves

Answer 2

a. Audible prosthetic clicks (metal) on approach
b. Scars on inspection
1- Midline sternotomy (CABG, AVR, MVR)
2- Lateral thoracotomy (MVR, mitral valvotomy, coarctation repair, BT shunt)
3- Subclavicular (Pacemaker, AICD)
4- Anticubital fossa (angiography)
–> Also look in the wrist and groins for angiography scars/bruising and legs for saphenous vein harvest used in bypass grafts.

C. Anticoagulation: bruises (metal valve) and anaemia

Question 3

Aortic valve replacement Auscultation

Answer 3

• A metal prosthetic closing click (CC) is heard instead of A2.
• There may be an opening click (OC) and ejection systolic flow murmur.
• A bioprosthesetic valve often has normal heart sounds.
• Abnormal findings:
  => AR
  => Decreased intensity of the closing click (clot or vegetation)

Question 4

Mitral valve replacement Auscultation

Answer 4

• A metal prosthetic closing click is heard instead of S1.
• An opening click may be heard in early diastole followed by a low-frequency diastolic rumble.
• Abnormal findings:
  => MR
  => Decreased intensity of the closing click.

Question 5

Operative mortality in valve replacement

Answer 5

3–5%

Question 6

Late complications of Prosthetic Valves

Answer 6

1. Thromboembolus: 1–2% per annum despite warfarin
2. Bleeding: fatal 0.6%, major 3%, minor 7% per annum on warfarin
3. Bioprosthetic dysfunction and LVF: usually within 10 years, can be treated percutaneously (valve‐in‐valve)
4. Haemolysis: mechanical red blood cell destruction against the metal valve
5. Infective endocarditis:
⚬⚬ Early infective endocarditis (<2/12 post‐op) can be due to Staphylococcus epidermidis from skin
⚬⚬ Late infective endocarditis is often due to Strep. viridans by haematogenous spread
⚬⚬> A second valve replacement is usually required to treat this complication
⚬⚬> Mortality of prosthetic valve endocarditis approaches 60%
6. Atrial fibrillation: particularly if MVR

Question 7

Choice of valve replacement (Metal Vs Procaine)

Answer 7

Metal:
- For: Durable
- Against: needs warfarin
- Indicated for: Young Pt/on warfarin, e.g. for AF
Procaine:
- For: No warfarin
- Against: Less durable
- Indicated for:
- Elderly >65 for MVR and 70 for AVR
- at risk of haemorrhage
- poor complaince to meds
- young women of childbearing age

Question 8

scars on the Chest for Heart conditions

Answer 8

1. Midline sternotomy (CABG, AVR, MVR)
2. Lateral thoracotomy (MVR, mitral valvotomy, coarctation repair, BT shunt)
3. Subclavicular (Pacemaker, AICD)
4. Anticubital fossa (angiography)

Also look in the wrist and groins for angiography scars/bruising and legs for saphenous vein harvest used in bypass grafts.