5: Rheumatic valvular heart disease Flashcards
(49 cards)
1
Q
purpose of valves, and how damage results
A
- 4 cardiac valves:
- Tricuspid
- Mitral
- Pulmonic
- Aortic
- Maintain unidirectional blood flow
- Suffer from high levels of repetitive mechanical stress
2
Q
which valve is described as following?
- 3 thin, delicate cusps
- Coronary artery orifices above it
- Smooth, shiny
A
AORTIC VALVE
3
Q
which valve is described as following?
- 3 thin, delicate leaflets
- Thin chordae tendineae attaching leaflet to papillary muscles of ventricular wall
A
TRICUSPID VALVE
4
Q
2 types of valvular disease?
A
STENOSIS or INSUFFICIENCY
5
Q
Type of valvular disease associated w/ the following?
- Failure to open completely
- Obstructs forward flow
- Due to primary cuspal abnormality from a chronic process
- Leads to pressure overload cardiac hypertrophy
A
STENOSIS
6
Q
Type of valvular disease associated w/ the following?
- Failure to close completely
- Regurgitation of blood
- Due to intrinsic disease of cusps (endocarditis) or secondary (disruption of supporting structures)
- Leads to volume overload
A
INSUFFICIENCY
7
Q
pathophys of mitral stenosis?
A
postinflammatory scarring (rheumatic heart disease)
8
Q
pathophys of mitral regurgitation?
A
-
abnormalities of leaflets and commissures
- postinflammatory scarring
- ineffective endocarditis
- mitral valve prolapse
- “Fen-phen”- induced valvular fibrosis
-
abnormalities of tensor apparatus
- rupture of papillary muscle
- papillary muscle dysfunction (fibrosis)
- rupture of chordae tendineae
-
abnormalities of left ventricular cavity and/or annulus
- left ventricular enlargement
- myocarditis, dilated cardiomyopathy
- calcification of mitral ring
9
Q
pathophys of aortic stenosis?
A
- postinflammatory scarring (rheumatic heart disease)
- senile calcific aortic stenosis
- calcification of congenitally deformed valve
10
Q
pathophys of aortic regurgitation?
A
-
intrinsic valvular disease
- postinflammatory scarring (rheumatic heart disease)
- infective endocarditis
-
aortic disease
- degenerative aortic dilation
- syphilitic aortitis
- anklylosing spondylitis
- rheumatoid arthritis
- marfan syndrome
11
Q
what accounts for 2/3 of all valvular disease?
A
acquired stenosis of Aortic valve and Mitral valve
12
Q
what infection causes rheumatic fever?
A
- acute, immunologically mediated multisystem inflammatory disease occurs after group A β-hemolytic streptococcal infection (usually pharyngitis)
- Incidence declined in the Western world
13
Q
what is rheumatic heart disease (RHD)?
what is the characteristic lesion associated?
A
cardiac manifestation of rheumatic fever
- Acute & chronic
- Characteristic lesion – fibrotic valvular disease (MV)
14
Q
what is the pathogenesis of rheumatic fever and heart disease?
A
- results from a hypersensitivity reaction –> antibodies directed against M proteins of certain Strep strains cross-react w/ host myocardial antigens
- Antibody binding –> activates complement, recruits macrophages, & neutrophils, cytokine production by T-cells leads to macrophage activation
Genetic susceptibility (~3% will develop RF)
15
Q
the hypersensitivity reaction of Rheumatic fever/ heart disease causes pancarditis of which valves?
A
- Mitral valve alone - 70% of cases
- Mitral valve + aortic valve - 25% of cases
16
Q
what are the key morphological features of acute rheumatic fever?
A
- Anitschkow cells - (pathognomonic for RF); plump, elongated macrophage with slender wavy central, condensed chromatin (caterpillar cells)
-
Aschoff bodies -
- collections of primarily T lymphocytes, plasma cells, and plump activated macrophages
- aka mononuclear cells, histiocytes w/ abundant cytoplasm, central nucleoli, can be binucleated (image)
17
Q
what are the features of pancarditis associated w/ Acute Rheumatic Fever?
A
- Pericarditis – fibrinous exudate–> friction rub
- Myocarditis – scattered Aschoff bodies –> arrhythmias, heart failure
- Valvular disease – verrucous vegetations (1-2 mm) along the lines of closure
18
Q
what are caterpillar cells?
A
Anitschkow cells: plump, elongated macrophage with slender wavy central, condensed chromatin (caterpillar cells)
19
Q
what are the morphological changes of chronic rheumatic fever?
A
- Replace acute lesions with scarring
- leaflet thickening
- commissural fusion and shortening
- thickening and fusion of chordae tendineae
- MV virtually always involved –> mitral stenosis –> “fish mouth” appearance
20
Q
what is this gross anatomical finding associated with?
A
fibrous thickening, commissural fusion (fishmouth);
associated w/ CHRONIC Rheumatic Fever
21
Q
what is this gross anatomical finding associated with?
A
Neovascularization of valve, thickened, fused chordae;
associated w/ Chronic Rheumatic Fever
22
Q
clinical features of acute rheumatic fever
A
- Timing: appears 10 days to 6 weeks after infxn in 3% of patients
- Clinical sxs:
- Pharyngeal cultures are usually negative
- Antibodies against strep are elevated (streptolysin O or DNAase)
- After 1st attack, patient has increased vulnerability to reactivation of disease with subsequent pharyngeal infection
23
Q
what is the following auscultation finding? what condition is it associated with?
“opening snap followed by diastolic rumble”
A
- mitral stenosis
- associated w/ acute rheumatic fever
24
Q
To diagnose: serologic evidence of a previous Strep infection + 2/- Jones Criteria
(Jones Criteria includes what?)
A
- Carditis
- Migratory polyarthritis of large joints
- Subcutaneous nodules
- Erythema marginatum
- Sydenham chorea
25
what are the minor criteria associated with Rheumatic Fever?
* fever,
* arthralgias,
* EKG changes,
* elevated acute phase reactants
26
what is the most common cause of **aortic stenosis**?
what causes this?
* **Calcific Aortic Stenosis;**
* Result of recurrent chronic injury (hyperlipidemia, hypertension, inflammation) , due to age-related “wear and tear”
27
**Calcific Aortic Stenosis:**
epidemiology
* Incidence increases with age (70s-80s, but 40s-50s in those with bicuspid AV)
* **Bicuspid aortic valve** – 1-2% of all live births, 2 cusps of unequal size **(NOTCH1 mutations)**
28
what are the **complications of aortic stenosis?**
* **Concentric LV hypertrophy** - may progress to HF
* **Angina and syncope with exercise** - limited ability to increase blood flow across stenotic valve
* **Microangiopathic hemolytic anemia** - RBCs damaged while crossing the calcified valve
29
describe the pathology of **mitral valve prolapse** (MVP)?
* **Myxomatous Degeneration** --\> One/both leaflets are “floppy” and prolapse
* Etiology is unclear (likely disorders of connective tissue - Marfan syndrome)
* Primary MVP: F \>\>\> M
* Secondary MVP: M=F
30
**mitral valve prolapse (MVP)** - morphology
**Ballooning of the leaflets**
* **Chordae** can be elongated, thinned, and may rupture
* **Valve leaflets** undergo fibrotic thickening (\<--rubbing against each other)
* **LV endocardial surface** undergoes linear fibrous thickening (\<--long cords rub against surface)
* **Mural endocardium** of LV/LA thickens
* **Atrial surfaces** of the leaflets/ atrial walls develop thrombi
31
which histo slide is normal?
what is the characteristic sign of a **myxomatous mitral valve?**
* Left side is normal
* Right side is **myxomatous mitral valve:**
* **collagen** in the fibrosa is **loose & disorganized**
* **\*\*proteoglycan deposition (mucoid/myxoid material) in the spongiosa is
markedly expanded**
* **elastin** in the atrialis is **disorganized**
32
what are the clinical features of **mitral valve prolapse** associated w/ Myxomatous degeneration?
* Most are asymptomatic
* Palpitations, dyspnea, chest pain
* **\*Midsystolic click\*** on ausculation
* 3% of patients will develop complications
* Infective endocarditis
* Mitral insufficiency with chordal rupture
* Stroke
33
what is: **Microbial infection of the heart valves or endocardium** that leads to formation of vegetations often assoc. with destruction of underlying cardiac tissue
Infective endocarditis
34
which bacteria is associated w/ **Acute Infective Endocarditis**?
* **(Staph aureus)**
* destructive infections, highly virulent organism attacking a previously normal valve
* **substantial morbidity and mortality,** even with appropriate antibiotic therapy and/or surgery.
35
which bacteria is associated w/ **Subacute Infective Endocarditis?**
* **(Strep viridans)**
* infections by organisms of low virulence affecting a previously abnormal valves (scarred/deformed)
* follows a protracted course of weeks to months; most patients recover
after appropriate antibiotic therapy.
36
pathogenesis of **infective endocarditis**?
* Starts with seeding of the blood with microbes
* Develops on normal, damaged, or prosthetic heart valves
* RHD, MVP, bicuspid AV, calcific valvular stenosis
10% culture negative endocarditis
37
most of the **damaged/defomed valves** are affected by which bacteria?
* **50-60%** of cases affecting damaged/deformed values
* **Streptococcus viridans** (part of normal oral flora)
38
most of the **normal/damaged** valves are affected by which bacteria?
* 10-20% normal/damaged valves
* **Staph. aureus**
* Major cause in IV drug users
39
which causative organism causes infective endocarditis in **prosthetic valve?**
**Staphylococcus epidermidis**
40
what are the **HACEK** group of organisms associated w/ infective endocarditis?
* Haemophilus
* Actinobacillus,
* Cardiobacterium
* Eikenella
* Kingella
41
what is the key morphology of Infective Endocarditis?
* Friable, bulky, **destructive** vegetations that contain fibrin, inflammatory cells, microorganisms
* **Ring abscess** – vegetations erode into underlying myocardium and form an abscess cavity
* Aortic and mitral valves are most commonly infected
* Tricuspid valve frequent target in IV drug users
42
symptoms associated with Infective Endocarditis?
* Fever, fatigue, weight loss, flu-like symptoms
* Murmurs in 90% with left-sided lesions
43
What are the microscopic pathological features in infective endocarditis?
what clinical presentation does this cause?
* **Microemboli** --\> petechiae, splinter hemorrhages, retinal hemorrhages (**Roth spots**), painless palm or sole erythematous lesions (**Janeway lesions**), painful fingertip nodules (**Osler nodes**)
* Glomerulonephritis
* Fatal if untreated
44
two families of noninfected vegetations?
1. Nonbacterial thrombotic endocarditis
2. Endocarditis of systemic lupus erythematosus (SLE)
45
**Nonbacterial Thrombotic Endocarditis:**
*pathology*
* Deposition of **sterile thrombi** on valves (underlying hypercoagulable state)
* Mucinous adenocarcinoma
* Also by indwelling catheters (endocardial trauma)
46
**Nonbacterial Thrombotic Endocarditis**:
## Footnote
*describe the vegetations; location, etc*
* Vegetations are **non-destructive and small (1-5 mm)**
* Located along the line of closure of leaflets/cusps
* Usually occurs on previously normal valves
* Vegetations can also be a nidus for bacterial colonization --\> infective endocarditis
47
**Endocarditis of Systemic Lupus Erythematosus (SLE) aka. Libman-Sacks Endocarditis:**
*describe the pathology and vegetations,*
* Path: **Immune complex deposition** --\> inflammation --\> can lead to fibrosis and scarring, similar to chronic RHD
* **Sterile, small (1-4 mm) vegetations** on valves of patients with SLE
* Mitral and tricuspid valves
* Located on valve undersurface, cords, endocardial surfaces
48
**Endocarditis of Systemic Lupus Erythematosus (SLE) aka. Libman-Sacks Endocarditis:**
*histo, and epidemiology*
* Histology – fibrinous, pink material with cellular debris, valvulitis (fibrinoid necrosis of valve substance)
* Epi: 10% of SLE patients
49
what % of pts will develop serious prosthesis-related problems w/ **prosthetic valves?**
60% will develop serious prothesis-related problems within 10 years of surgery (thromboembolism, infective endocarditis, etc)
