Cardiac Surgery Flashcards
What is the target INR for these type of valves?
-bileaflet mitral valve
-bileaflet aortic valve
-caged ball valve (aortic or mitral)
-bileaflet mitral valve 3.0
-bileaflet aortic valve 2.5
-caged ball valve (aortic or mitral) 3.5
For patients with bioprosthetic valves, what is the indication for long term anticoag and target INR?
For bioprosthetic valves, short term anticoag for 3 months but there is no indication for long term anticoagulation unless there is systemic embolism/intracranial thrombus. INR will be 2.5 in this case
When is bridging therapy indicated? What is it?
How do you start bridging therapy?
How much enoxaparin should patient have on day before high risk procedure/surgery
Bridging therapy is replacing long acting anticoagulant warfarin with a long t1/2 with LMWH that has short t1/2 life.
It is started for patients of high VTE risk that are undergoing procedures of bleeding risk and cannot come off anticoagulation completely due to risk. For example, those with mechanical valves or previous VTE.
Starting bridging therapy:
Make sure last dose of warfarin is 36-48h before starting therapeutic dose LMWH
Start therapeutic dose LMWH enoxaparin 1mg/kg BD
Day before procedure or surgery:
Half dose LMWH 1mg/kg OD
What type of valve is resilia heart valve?
What is it made from and its advantages over mechanical valve?
Resilia heart valve is a bioprosthetic valve that is made from the cow’s heart. It is v resistant to calcification.
Because it is bioprosthetic, patients do not need to be on long term anticoag unless they have high VTE risk
It is dry and does not need to be submerged in sterile water before insertion
What type of valve is the Medtronic open pivot valve?
What’s an advantage of this valve over bioprosthetic valve? How long does a mechanical valve last for c/f to bioprosthetic?
What size is an open pivot mitral valve vs aortic valve?
What is AP 360?
Medtronic open pivot valve is a mechanical bileaflet valve. It has advantages due to low risk of VTE because:
-no recesses or cavities; no blood stasis to form clots
-minimal turbulence
-continuous washing of open/closed valves
It is more durable than a bioprosthetic valve due to the material-titanium and carbon. It can last for 30+ years unlike bioprosthetic 10-15 years
Open pivot mitral valve
-25-33mm
Open pivot aortic valve
-19-31mm
AV stenosis
What is the normal size for AV valve
What is considered mild AS
Moderate AS
Severe AS
AV valve normal 2.5-4.5cm 2
Mild AS 1.0-2.5
Moderate AS 0.75-1cm 2
Severe AS< 1cm2
