What kind of valves are Hancock and Carpentier-Edwards?

Porcine valves

Which brand name of porcine valves is the most common?

Carpentier-Edwards

In what valve positions are Hancock and Carpentier-Edwards’ valves used?

Mitral, aortic and tricuspid valve positions

How long will a Carpentier-Edwards or a Hancock valve last?

10 – 15 yrs

How are Carpentier-Edwards or Hancock valves made?

They are constructive of aortic porcine valves sewn to a metal wire stent, often made from a cobalt-nickel alloy.  The wire is bent to form three U-shaped prongs.  A Dacron cloth sewing skirt is attached to the base of the wire stent, and the stents themselves are also covered with cloth.

True/False- Carpentier-Edwards or Hancock valves are treated with gluteraldehyde to make them stiffer?

TRUE

What is a disadvantage of Carpentier-Edwards or Hancock valves?

Limited sizes are available & Small valve sizes will sometimes have “incomplete openings” due to small orifice, and with lower flow rates, creates a favorable environment for failure (size mismatch).

What kind of valve is an Ionescu-Shiley valve?

Bovine tissue valve

What material is used to make Ionescu-Shiley valves?

Fashioned from cow pericardium

How will an Ionescu-Shiley valve fail?

Valvular regurgitation or stenosis are the common methods of failure.

What is the advantage of Ionescu-Shiley valves?

Unlimited range of sizes can be custom designed.

What are the brand names of Ball-In-Cage valves?

Starr Edwards silastic ball, Starr Edwards satellite ball, & Smeloff Cutter

What was the brand name of the first mechanical valve in 1952 and what type of mechanical valve was it?

Starr Edwards silastic ball & Ball-In-Cage  

How are Smeloff Cutter or Starr Edwards valves constructed?

Two U-shaped struts form a cage that houses a silastic ball occluder.

What is the mechanism of failure for a Smeloff Cutter or Starr Edwards valve?

The ball would swell and freeze in the open or closed position

What type of medication will a patient have to take with a Smeloff Cutter or Starr Edwards valve?

Anticoagulants- mechanical valves have increased thrombogenicity.

What is the disadvantage of Smeloff Cutter or Starr Edwards valves?

The ball was notorious for causing damage to blood cells due to collisions.

Are Smeloff Cutter or Starr Edwards valves still being used today?

No, they were eventually taken off the market.

What kind of valves are Medtronic-Hall or Bjork-Shiley valves?

Single Disc Tilting Disc valves

Which brand name of Single Disc Tilting Disc valves is the most common?

Bjork-Shiley valves & Single Disc Tilting Disc valves

How was the Bjork-Shiley or Medtronic-Hall valves supposed to be an improvement over Starr Edwards or Smeloff Cutter valves?

Bjork-Shiley or Medtronic-Hall valves were designed to mimic the natural patterns of blood flow.  This reduced damage to blood cells, improved flow patterns, reduced blood clotting and infections.

What is the mechanism of failure for a Bjork-Shiley or Medtronic-Hall valve?

The struts tend to fracture due to fatigue from repeated ramming of the struts by the disc.

How are Bjork-Shiley or Medtronic-Hall valves constructed?

A polymer disc held in place by 2 welded struts.  The disc floats between the two struts in such a way, as to close when the blood begins to travel backward and then reopens when blood begins to travel forward again.

How are St. Jude’s or CarboMedics valves constructed?

Consisted of 2 semi-circular leaflets that pivot on hinges.  The carbon leaflets were strong and had excellent biocompatibility.

When was the first St. Jude’s or CarboMedics valves introduced?

1979

When performing Doppler on a St. Jude’s or CarboMedics valve where should the cursor be placed to get an accurate velocity? Why?

Move the cursor to the side a little because the unusual profile causes the flow velocities to be higher when obtained from the central, slit like orifice.

True/False- St. Jude’s or CarboMedics valves provide the closest approximation to central flow achieved in a natural heart valve.

TRUE- The leaflets swing open completely, parallel to the direction of blood flow. 

True/False- St. Jude’s or CarboMedics valves are considered an ideal valve.

FALSE- The leaflets don’t close completely, which allows some backflow. Since this is a property of a defective valve, the bi-leaflet valve is still not an ideal valve. 

What are the brand names of Bi-Leaflet Tilting Disc valves?

St. Jude’s & CarboMedics

Which brand name of Bi-leaflet Tilting Disc valves is the most common?

St. Jude’s valves

True/False- Regurgitation of prosthetic valves appears the same severity on both TTE and TEE?

FALSE- The regurgitation always appears worse on TEE than on TTE.

List 4 things in which serial exams of prosthetic valves will include.

1-      CW velocities (antegrade) through the valve,

2-      Look for any change in the amount of “normal” prosthetic valvular regurgitation

3-      Appearance of perivalvular leaks d/t dehiscence or abscess

4-      Heart changes such as LVH, chamber dilatation, or ventricular dysfunction d/t wrong size valve used.

Is a baseline echo needed for a prosthetic valve once the valve has been implanted?

YES- a baseline echo will establish what is normal for the prosthetic valve and can be used to compare later echo studies to see if anything has changed with the prosthetic valve.

True/False- Wedge pressures are not affected by implantation of prosthetic valves.

FALSE- Once a prosthetic valve is in place, invasive information of valvular malfunction in the mitral or aortic position requires transthoracic or transeptal puncture cardiac catherization to assess the hemodynamics.  Wedge pressures can no longer be performed.

What kind of information does a “medical device card (MDC)” provide?

Manufacturer of prosthetic valve, model number of prosthetic valve and size of prosthetic valve

How will velocities change with prosthetic valve in comparison to a native valve?

Peak velocities will be increased with a prosthetic valve from those obtained in native valves.

List the Doppler tools which are used for assessment of all prosthetic valves.

1- CW

2- Color Doppler

True/False- The continuity equation can be used for all prosthetic valves to calculate the AVA.

FALSE- The continuity equation can be used to tissue valves, but not mechanical valves.

What is the name of the index which is used for assessment of the aortic valve prosthetics and what kind of prosthetic valve uses it?

Dimensionless Index & Mechanical Valves

What is the ratio used for calculation of the dimensionless index for mechanical valves?

LVOT VTI ÷ AOV VTI

Using a VTI of 15 for LVOT and a VTI of 51 for the AOV, calculate the ratio and is it stenotic?

15÷51 = .29

Yes- <0.3 is stenotic

What are the units of the dimensionless index?

There are no units for the dimensionless index.

What’s the normal range for the dimensionless index and when is it considered to be stenotic?

Normally between 0.35 - 0.5

<0.3 is stenotic

What valve positions can be assessed with the P1/2T & VTI tracing methods?

Mitral and Tricuspid valve areas

Which method is more accurate for calculating prosthetic valve velocities in the mitral and tricuspid valve positions?

VTI calculation to get the mean gradient is more accurate.  Normal values must be looked up in a table for each valve.

When should a baseline ratio be performed?

6 months after surgery

List everything that can assess regurgitation in a prosthetic valve.

1-      Color to determine jet width, origin, and jet area

2-      PW to look for S wave reversal in the pulmonary or hepatic veins with severe MR or TR

3-      PW to assess severity of AI in descending aorta

4-      CW to assess flow shape for acute or chronic MR and severity

True/ False- It can be very difficult to discern perivalvular leakage d/t the fact that many mechanical valves normally have unusual color patterns that make it difficult to tell.

TRUE

How will a ring abscess appear on 2D echo?

An anechoic area surrounding the annulus

What is the brand name of the prosthetic valves which are in clinical trials and are not yet approved by the FDA?

3F Therapeutics

True/False- Anechoic areas in the annulus suggest perivalvular abscess, color Doppler is necessary to determine the presence of perivalvular leakage in patients with no dehiscence.

TRUE