Prosthetic valves Flashcards
What is the most common indication for valve replacement surgery?
Aortic stenosis is the most common indication for valve replacement surgery.
What is the second most common indication for valve replacement surgery?
Mitral regurgitation is the second most common indication for valve replacement surgery.
What is the most common surgical approach for valve replacement?
The most common surgical approach is a midline sternotomy (a vertical incision down the middle of the chest).
What is the alternative surgical approach for minimally invasive mitral valve surgery?
A right-sided mini-thoracotomy incision may be used for minimally invasive mitral valve surgery.
What is the lifespan of a bioprosthetic valve?
A bioprosthetic valve has a limited lifespan of around 10 years.
What is the primary difference between bioprosthetic and mechanical valves?
Bioprosthetic valves last about 10 years, while mechanical valves last over 20 years but require lifelong anticoagulation therapy.
What type of anticoagulation is required for patients with mechanical valves?
Patients with mechanical valves require lifelong anticoagulation with warfarin, aiming for an INR target range of 2.5 – 3.5.
What is the risk for thrombus formation in mechanical heart valves?
Mechanical heart valves carry a risk of thrombus formation due to blood stagnation and clotting.
Which valve is commonly used and has the smallest risk of thrombus formation?
The St. Jude bileaflet valve, which features two tilting metal discs, has the smallest risk of thrombus formation.
What sound can be heard during auscultation of a mechanical heart valve?
A click sound may replace S1 or S2: Mitral valve: Click replaces S1. Aortic valve: Click replaces S2.
What are the major complications of mechanical heart valves?
The three major complications are:
* Thrombus formation (blood clots).
* Infective endocarditis (infection in the valve).
* Hemolysis (anemia caused by blood damage in the valve).
What is TAVI and when is it used?
TAVI (Transcatheter Aortic Valve Implantation) is used for patients with severe aortic stenosis who are high-risk for open surgery. It involves inserting a catheter through the femoral artery to implant a bioprosthetic valve.
Do patients who undergo TAVI require anticoagulation therapy?
No, patients with a TAVI do not typically require warfarin because the valve is bioprosthetic.
What is the rate of infective endocarditis in patients undergoing valve replacement surgery?
Infective endocarditis occurs in about 2.5% of patients undergoing surgical valve replacement, and slightly lower in TAVI patients (1.5%).
What are the common causes of infective endocarditis in prosthetic valves?
It is usually caused by gram-positive cocci organisms:
* Staphylococcus
* Streptococcus
* Enterococcus
