mechanical valves
caged-ball and tilting disk (single and bileaflet)
what is a homograft?
valve transplanted from another human
what is leakage? what does it provide?
occurs AFTER valve is closed; found between & around occluder mechanism
provides washing mechanism to prevent thrombus formation
a ring abscess from endocarditis in mechanical valves can cause?
Dehiscence, perivalvular regurgitation, abscess may extent into myocardium & even further into conduction system
what is an annuloplasty ring and what is it good for?
flexible but inelastic material which allows ring to conform to normal physiologic function of annulus
Good for MVP (specifically posterior prolapse) which the ring improves leaflet coaptation & mobility
what do caged ball valves completely block? how does that affect the heart
completely block central flow, more energy required, so heart has to work harder
what are advantage of bioprosthetic valves over mechanical valves?
Closer to design of native valves, do not require long-term anticoagulants due to better hemodynamics
how are prosthetic valves essentially stenotic?
from sewing ring being too small relative to flow & EOA significantly smaller than sewing ring area
what are false positives of obstructions caused by vegetations?
pannus or loose suture material
what is an alfieri or edge to edge repair? potential cause/outcome?
free edges of the MV leaflets are sutured together at the site of MR
potentially create a degree of MS
what does the bileaflet tilting disk consist of?
3 orifices; two larger openings on either side & smaller central rectangular orifice in the middle
what is a TAVR?
transcatheter aortic valve replacement - tissue valve mounted in balloon-expandable or self-expandable stent
what are other structural abnormalities that can be seen on echo?
dehiscence, vegetation, thrombus
what is prosthetic patient mismatch? how does it affect the patient?
when the EOA too small to accommodate needed flow causing a marked transvalvular gradient
Function is well at rest but cant handle hemodynamic demand with exercise
what is a mitral clip?
same process as edge to edge repair but with a clip instead of suture
what valve closest models central flow like found in native valves?
bileaflet tilting disk
what is the Ross procedure?
2D imaging is hampered with when imaging prosthetic valves causing reflectance of valve material due to what?
the speed of sound changes as it passes through prosthetic material which distorts size & appearance
This leads to shadowing & reverberation
what is ball variance?
when the ball gets stuck in the cage due to change in shape of occluder
what is a bilateral repair?
minimally invasive procedure that restored valve function using annuloplasty ring, leaflet resection, chordal reconstruction for the TV and MV
what prosthetic valve is two welded struts that hold disk in place to control motion
single tilting disk
what are re-operation reasons for porcine stentless valves?
degeneration with regurgitation, stenosis, endocarditis, sinus of valsalva aneurysm
how can you prevent/improve artifact on 2D imaging with prosthetic valves?
decrease gain, use multiple windows, angulations, and off-axis images to fully interrogate valve and area around
thrombus causes 90% of obstructions and is more common where? higher where?
more common in mechanical valves; higher in MV than AV
flow through a TVR is at a lower or higher velocity? what risks come with that?
lower; risk of thrombus formation is higher