Valvular Disease Flashcards
Stenosis (valve)
Narrowing of a valve
Regurgitation (valve)
Insufficiency of a valve causes back flow of blood
Chorea
Chorea is characterized by involuntary brief, semi-directed, irregular movements that are not repetitive or rhythmic, but appear to flow from one muscle to the next.
What is the cell origin of angiosarcoma?
Arise from endothelial cells
What is the general structure of a valve?
Valves are lined by endothelium on both in-flow and out-flow surfaces and there is a collagenous core (3 parts – spongiosa, fibrosa, elastosa) of connective tissue
What are the semilunar valves?
Aortic and Pulmonic
What are the atrioventricular valves?
Tricuspid and Mitral
What is bicuspid aortic valve?
Congenital malformation where the aortic valve has 2 cusps instead of 3 and the cusps are usually of unequal size.
What may develop later on as a complication of bicuspid aortic valve?
Aortic stenosis may develop at age 50’s and 60’s
What are people with bicuspid aortic valves predisposed to?
There is a predisposition to infective endocarditis
Valvular Degeneration Caused by Calcification
Valves are subject to high repetitive mechanical stresses which leads to cumulative damage to the delicate valves and deposition of calcium phosphate minerals
What patients are at increased risk of valve degeneration via calcification?
Chronic injury due to hyperlipidemia,
hypertension, inflammation may have a role in and may precede the characteristic calcification - similar to atherosclerosis but is a distinct process
What is calcific aortic stenosis?
Heaped up calcified masses within the aortic cusps protrude through outflow surfaces and prevent the opening of cusps leading to stenosis.
When does calcific aortic stenosis manifest in patients with bicuspid aortic valves? And when does it occur for those with normal valves?
Stenosis manifests clinically in 50’s and 60’s (stenosis may manifest at an earlier age since bicuspid valves incur greater mechanical stress than normal tricuspid valves)
If calcification affects structurally normal valves -stenosis usually manifests clinically in age 70’s and 80’s
What is Myxomatous Degeneration of the Mitral Valve also known as?
Mitral Valve Prolapse
Who is most commonly affected with mitral valve prolapse?
Young women
What is the pathology of mitral valve prolapse?
One or both mitral valve leaflets are enlarged, redundant, rubbery - Floppy valves balloon back (prolapse) into left atrium during systole
What happens to the mitral valve histologically in mitral valve prolapse?
Histologically the valve leaflets have deposition of mucoid/myxomatous material
What is the presentation of mitral valve prolapse?
Majority of patients are asymptomatic. There are rare serious complications – development of infective
endocarditis, development of mitral valve insufficiency
What is infective endocarditis?
Destructive inflammation of cardiac valves and endocardium - vegetations can often be seen
What is the most common cause of infective endocarditis?
Bacterial infection of a valve is the most common cause
Acute Infective Endocarditis
Caused by highly virulent organisms
-Staphylococcus aureus
Results in a rapid clinical course with severe destruction of valves - Affected valves are often previously normal
Subacute Infective Endocarditis
Caused by low virulence organisms - alpha-hemolytic (viridans) Streptococci
Affects previously deformed valves with less valvular destruction
What are vegetations?
Composed of thrombotic debris, fibrin, inflammatory cells,
microorganisms - friable which leads to embolisms
What are some risk factors for the development of infective endocarditis?
i. Preexisting valvular disease
ii. Prosthetic valves
iii. Immune deficiency
iv. Diabetes mellitus
v. Intravenous drug abuse
vi. Alcoholism
What are some major complications of infective endocarditis?
i. Cardiac
- Valvular insufficiency (or stenosis)
- Abscess formation
- Prosthetic valve dehiscence or paravalvular leak
ii. Embolic complications
What is Nonbacterial Thrombotic Endocarditis also known as?
Marantic Endocarditis
What are the characteristics of Marantic Endocarditis?
Characterized by small (1-5mm), sterile vegetations on cardiac valves.
- Vegetations are composed of fibrin, platelets
- Vegetations are non-destructive but loosely attached to valves
What is Endocarditis of Systemic Lupus Erythematosus also known as?
Liebman-Sacks Endocarditis
What are the characteristics of Liebman-Sacks Endocarditis?
Small (1-4mm) sterile vegetations in patients with Systemic Lupus Erythematosus
- Consequence of immune complex deposition leading to valvulitis
- Most commonly seen on mitral and tricuspid valve undersurfaces
- May be associated with marked inflammation and necrosis of valve
What is the pathogenesis of acute rheumatic fever?
Acute, immunologically mediated, multisystem inflammatory disease and occurs 6-10 days after Group A (B-hemolytic) streptococcal pharyngitis due to cross reaction of antibodies.
- Antibodies directed against M proteins of strep cross-react with self-antigens in the heart
Who is most commonly affected by acute rheumatic fever?
Most commonly seen in children 5-15 years old
What is CHRONIC rheumatic fever?
Clinical manifestations develop years to decades after episode of acute rheumatic fever
-Manifests as valvular disease – most commonly mitral stenosis
What are the major criteria for acute rheumatic fever?
- Joints with migratory polyarthritis of large joints
- ❤Carditis
- Subcutaneous nodules
- Erythema marginatum of skin
- Sydenham chorea
What are the minor criteria for acute rheumatic fever?
- Fever
- Arthralgias
- Elevated acute-phase reactants
What is a common finding with chronic rheumatic fever?
-Valve leaflets become thickened, fused and the leaflet thickening and fusion can results in a classic “fish
mouth” or “ buttonhole” stenosis
What are Aschoff bodies comprised of?
– T lymphocytes – plasma cells – macrophages • Anitschkowcells (caterpillar cells) – multinucleated cells
What is pancarditis comprised of?
- Pericarditis
- Myocarditis
- Endocarditis
What is carcinoid heart disease?
Endocrine tumors most commonly involving the gastrointestinal tract and lung which secrete bioactive products – serotonin (5-hydroxytryptamine),
kallikrein, bradykinin, histamine, prostaglandins, tachykinins that affect the heart
How is the heart affected by carcinoid tumors and what is the most commonly affected part of the heart?
Affects the right side of the heart.
The endocardium and valves develop a plaque-like thickening and the pathogenesis is not entirely understood but there is a correlation of serotonin levels with the development of right sided heart disease
