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The 2 types of prosthetic valves are:
- 1. Mechanical
- 2. Bioprosthetic
Why do patients have prosthetic valves?
- 1. When medication isn't an option
- 2. Stenosis
- 3. Incompetance
List the 3 main components of mechanical valve with a brief definition
- 1. Occluder - moving component (ball) - comparable to leaflets
- 2. Restraining System - restricts motion of occluder (cage) - comparable to chordae tendinae
- 3. Sewing Ring - attaches prosthesis to vessel - comparable to pap muscles
List the 3 main mechanical valves
- 1. Ball & Cage
- 2. Tilting Disc
- 3. Bi-Leaflet
The most commonly used mechanical valve is __________________ because it _______________ _________________ similar to native valve.
What profile is a bileaflet mechanical valve?
Low profile (not as much movement)
List 2 disadcvantages for the mechanical prosthetic valves:
- 1. Lifetime anticoagulation drugs
- 2. Increased thromboembolic events
2 types of bioprosthetic valves are:
The main disadvantage of bioprosthetic valve is ___________________________________.
Doesn't last as long as a mechanical valve
Other prosthetic devices are: (2)
- 1. Valved Conduits
- 2. Carpentier Ring
What's a valved conduit used to repair? What material may it be? (2)
- Some types of congenital heart disease
- Homograft or artificial such as Gore-Tex or Dacron
Carpentier Ring is used to repair_______________________. (Durand)
What is a carpentier ring and how is it used?
What does it resemble?
Flexible ring that's sewn into annulus to help support the native ring.
Define: Pannus Formation
Fibrous ingrowth of tissue
Sutures of sewing ring loosen
List complications of a mechanical & bioprosthetic valves seen on an echocardiogram: (8) PATTD CH
Which ones are specific to bio vs. mech?
- Turbulent Flow
- Abscess Formation
- Mechanical failure
- Calcification or degeneration of valve (bioprosthetic)
- Hemolysis - RBC damaged as passing through mechanical valve
Can you tell the difference of Pannus due to endocarditis vs thrombus formation?
All prosthetic valves have higher velocities. Why? T/F
What does high profile mean? Low profile?
- High = lots of movement Ie: ball & cage
- Low = little motion Ie: bileaflet
Explain the difference in flow pattern of a prosthetic mitral valve vs a normal MV. Think of the picture you drew.
- Normal flow moves from MV to apex, curves and heads to AO valve.
- Prosthetic is directed toward mid LV anterior wall and then heads out AO valve. Done to avoid thrombus formation
Doppler of mechanical valves demonstrates valve click. What is valve click, and how can one use this to help with Dx of stenosis?
- Valve click = opening + closing of valve
- Stenosis = higher velocities than expected
With prosthetic valves the smaller orifice the _________________________ the velocity.
What is the MC brand of mechanical valve?
What type of low profile mechanical valve is no longer used?
A problem with mechanical valves is ___________________ PG.
MC bileaflet mechanical valve is ________________________.
What is the MC mechanical valve used?
Bileaflet tilting disc; St. Jude
Define: Heterograft (Xenograft)
mace from porcine or bovine tissue (animal)
AO valves harvested @ autopsy or dura mater
Patients own tissue (fascia lata, fibrous mmb from thigh muscle)
What is the name of the procedure when using an autograft?
Name the 3 main components of Bioprosthetic valves:
- 1. Mobile part - constructed of tissue (semilunar valves from pigs, cows or humans)
- 2. Restraining system - stents or struts
- 3. Sewing Ring
What is a disadvantage of using bioprosthetic valves?
Not as long lasting
Why would a Dr. choose a mechanical or bioprosthetic valve?
- 1. Young
- 2. Renal failure, small valve annulus, high reop risk
- 3. AO root replacement - dissection with severe AI
- 1. Elderly
- 2. Chronic anticoag not advised
- 3. High risk of thromboembolism
All prosthetic valves are inherintly _______________________.
Larger valve areas have _________________ velocities and PG and _________________ EOA.
Why when you have a smaller EOA with a higher velocity would the mean PG be lower even though PG is higher?
Less area to trace. Sawtooth shape
Is prosthetic regurg normal?
Name some limitations of prosthetic valves: (4 multi points)
- 1. reverberation, artifact, acoustic shadowing
- 2. Overestimation of transvalvular PG with bileaflet mechanical valves
- 3. Differentiating normal from pathologic prosthetic valve regurgitation
- 4. Detection of valvular vegetations is difficult d/t reverberations
What always accompanies a vegetation?
Whenever you have open heart surgery, expect to see :
paradoxical septal motion
Why does PISA work well on prosthetic valves?
Because of the forward flow
What is the MC cardiac trauma?
Stented bioprosthetic valves have an appearance similar to ______________________________.
Native AO valve
Bioprosthetic valve longevity
Why is the apical view not useful when assessing MR or mechanical prosthetic valve?