Valvular Heart Disease Flashcards
Which valves are the semilunar valves? How many cusps do they each have? What does their function/integrity depend on?
Aortic and Pulmonary Valves
3 cusps each
Function depends on integrity and coordinated movements of cusps and attachments
Which valves are the atrioventricular valves? How many cusps do they each have? What does their function/integrity depend on?
Tricuspid and Mitral
3 (tricuspid) and 2 (mitral)
Competency depends on leaflets + annulus, chordae tendinae, papillary muscles, ventricular wall
What is the valve leaflet core made of?
Collagen, elastin, ECM
What is the valve lined by on both the inflow and outflow tracts?
Endocardium
Bicuspid Aortic Valve
Describe what the problem is and what pathology it can lead to
Congenital disorder in which two cusps of the aortic valve have a midline raphe uniting them where they should normally be separated
Higher risk of developing aortic stenosis (in 50s or 60s) and infective endocarditis
May develops aortic dissections and aneurysms at higher rate
Valvular Degeneration due to Calcification
What causes it?
Normal “wear and tear” on the heart valves (there is some injury to the valves and they heal with fibrosis)
Atherosclerotic risk factors may also contribute to the development of this disease
Describe the problems caused by Calcific Aortic Stenosis
Calcified masses form on the aortic cusps, which prevent their opening, There is outflow obstruction and therefore an increased pressure gradient across the valve. Leads to concentric LV hypertrophy
Mitral Valve Prolapse is AKA…
Myxomatous Degeneration of Mitral Valves
Mitral Valve Prolapse
Describe the basic problem
Floppy, enlarged mitral valves leaflets balloon into the LA during systole
Can cause injury to the LA endothelium
What would you see on histology of mitral valve prolapse?
Deposition of extracellular mucus (myxomatous deposition within the valve tissue core)
What genetic disorder could lead to a greater risk of mitral valve prolapse?
Marfan’s Syndrome (fibrillin defect)
What would you hear on auscultation in mitral valve prolapse?
Midsystolic click from the valves ballooning into the atria during systole
Who most commonly is diagnosed with mitral valve prolapse? What do they normally present with?
Young women, commonly asymptomatic with no long term complications
Some have nonspecific symptoms (chest pain, dyspnea, fatigue)
What are some serious complications of mitral valve prolapse?
Infective endocarditis Mitral insufficiency Stroke/systemic infarct Embolism of a valve leaflet Arrhythmias
What is infective endocarditis? What is the characteristic finding?
Destructive inflammation of cardiac valves and endocardium, commonly due to bacterial infection
Vegetations growing on valve leaflets are common
What is a vegetation? What is it composed of?
Abnormal outgrowth of a body part, commonly made of fibrin and collagen with inflammatory cells and thrombotic debris
What is a common complication of a vegetation formed on a valve?
Embolization (the thrombi formed on the vegetations are not strong)
Acute IE
Most common cause?
Prior condition of valve?
Outcomes?
Usually Staph aureus infection.
Rapid and severe destruction of a previously normal valve
High mortality
Subacute IE
Most common cause?
Prior condition of valve?
Outcomes?
Usually a low virulence organism (like Strep. viridans)
May affect a previously deformed valve
Does not destroy valve quickly and responds well to antibiotics
Who are patients at greater risk for infective endocarditis?
Valve disease Prosthetic valves Immune deficiency Diabetes IVDAs Alcoholics
How does the infectious organism in infective endocarditis enter the body?
May come from an infection elsewhere.
Dental or surgical procedures with bacteremia.
Injection of contaminated materials into blood.
Symptoms of Endocarditis
Chest pain SOB New Murmur See vegetations on echo Blood cultures show bacteremia Splinter hemorrhages in the nailbeds Conjunctival petechiae Janeway lesions (nontender darkened areas on palms and soles) Osler Nodes (immune deposition in hands and feet)
What are the 3 situations where a vegetation could occur outside of an infection?
Nonbacterial Thrombotic Endocarditis
Endocarditis of SLE
Acute Rheumatic Fever
Nonbacterial Thrombotic Endocarditis
What is the clinical problem?
Sterile thrombi (vegetations) forming on valve leaflets Small, nondestructive, loosely attached
In what patients does Nonbacterial Thrombotic Endocarditis most commonly occur?
Patients in a hypercoagulable state
sepsis, cancer, burns, indwelling catheters
Nonbacterial Thrombotic Endocarditis
What complication are you worried about?
Embolization of the thrombus leading to infarcts or stroke
Endocarditis of Systemic Lupus Erythematosus (SLE)
What is the clinical problem?
Immune complex deposition and inflammation on valve leaflets (vegetations)
Causes “Valvulitis” to harm/destroy valve
Rheumatic Fever
What infection can cause this? How are these vegetations formed?
Group A Strep (S. pyogenes) infection that is untreated can lead to rheumatic fever
Antibodies are generated against strep M proteins, which have some cross reactivity to self antigens in the heart, leading to inflammation of the heart
Major Manifestations of Rheumatic Fever
JONES Migratory polyarthritis Carditis/Pancarditis Subcutaneous nodules Erythema marginatum Sydenham's Chorea
Minor Manifestations of Rheumatic Fever
Fever
Arthralgia
Elevated acute phase reactants
How do you confirm rheumatic fever diagnosis?
2 major manifestations
OR
1 major + 2 minor manifestations
What is pancarditis?
Inflammatory involvement of the pericardium, myocardium, and endocardium
What is seen histologically in the acute phase of rheumatic fever?
Aschoff Bodies
composed of T cells, plasma cells, macrophages (caterpillar cells = Anitschkow cells)
Which valve does chronic rheumatic heart disease typically involve? What happens?
Mostly on the L heart, mostly mitral.
Valve leaflet fibrosis and fusion.
Chordae tendinae become short, thick, and fused.
