Cv Module - Pathology Valvular Heart Disease

Front 1

What is the most important cause of Aortic Stenosis?

Back 1

MCC = Calcification

(1) MC - Acquired (>70yo): Degenerative valvular disease - Senile Calcific Aortic Stenosis

(2) Congenital (<70yo): Calcified bicuspid aortic valve

(3) Chronic Rheumatic HD, AS accompanied by AI



**2/3 of valvular HD is acquired (MC = AS, MS)

Front 2

What is the most important cause of Mitral Stenosis?

Back 2

MCC = Chronic Rheumatic heart disease: (mitral annular calcification)

Front 3

What is the most important cause of Aortic Regurgitation?

Back 3

MCC = Ascending Aortic Dilation

(1) Long-standing essential HTN
(2) Medial disease in the aortic root (dissection)
(3) Chronic rheumatic HD
(4) Infective endocarditis (MC LEFT-sided valve involved in IV drug abuse (S. aureus)
(5) Dilation of aortic valve ring:
--> syphilitic aortic aneurysm
--> Giant cell aortitis
--> dissecting aortic aneurysm (Marfan syndrome)
--> coarction of th aorta
(6) Ankylosing spondylitis: aortitis

Front 4

What is the most important cause of Mitral Regurgitation?

Back 4

MCC = Mitral Valve Prolapse d/t myxomatous degeneration

(2) Left HF d/t stretching of MV ring
Ex: ischemia (papillary muscle dysfunction OR Cardiomyopathy (all 3) OR Myocarditis

(4) Chronic Rheumatic HD

(5) Infective endocarditis

(6) Rupture of the chordae or papilary muslce (usually d/t Right CA Thrombosis)
(4) Infective endocarditis

Front 5

Describe the pathophysiology of Calcific Aortic Stenosis (acquired)

Back 5

**MC valvular abnormality

--calcification begins within the valvular fibrosa to form masses within and at the base of the aortic cusps

--functional valve area decrease so that comissural fusion is not produced
-Progressive degeneration with dystrophic calcification related to mechanical stress

Location:
Early lesion - cusp attachments and coaptation
Late lesion - valve leaflet (partial or complete)

**Tx surgically
**Mitral Valve is normal, except in RHD

Front 6

Describe the pathophysiology - Calcific stenosis of congenitaly bicuspid aortic valve

Back 6

Frequency - 1% live births
Gross: two functional cusps of unequal size

--functionally sufficient early in life
--Calcification occurs initially on the raphe present on the larger cusp
--remains relatively asymptomatic until middle age when stenosis reaches critical pt. and CHF rapidly ensues (pulmonary congestion and edema)
--Becomes incompetant d/t
(1) aortic dilation
(2) cusp prolapse
(3) infective endocarditis

**stenosis develops earlier than in acquired
**Mitral valve is normal

Front 7

Describe the clinical findings in Calcific Aortic Stenosis

Back 7

Clinical features:
-causes LVH (angina, syncope, decompensation with development of CHF)
-Myocardia ischemia and fibrosis
-pulmonary vascular disease (P-HTN)
-Endocarditis and emboli

Front 8

Howe does Mitral Annular Calcification affect valve function

Back 8

Calcification of the fibrous ring (annulus) of the mitral valve

DOES NOT USUALLY AFFECT VALVULAR FUNCTION!!

Front 9

What are some complications of Mitral Annular Calcification?

Back 9

Complications of doughnut shaped ring of calcification around mitral valve annulus:
-interferes with systolic contraction
-stenosis
-arrythmias
-sudden death
-strokes d/t emboli
-nidus for infectious endocarditis
-severe cases can lead to reguargitation

Front 10

Who does Mitral Annular Calcification usually affect?

Back 10

Women >60yo

Pts with myxomatous mitral valve

Pts with elevated left ventricular pressure

Front 11

Who does myxomatous degeneration of the mitral valve (Mitral Valve prolapse) usually affect?

Back 11

3% of US adults (mostly young women)

MC form of valvular heart disease in the INDUSTRIALIZED world

Front 12

What is the etiology of Mitral Valve Prolapse?

Back 12

Unknown

Theories:
(1) CT defect - assoc. with Marfan syndrome, others
(2) Systemic structural abnormalities of CT tissue - scoliosis, straight back, high arched palate
(3) Defects in structural proteins (elastin, microfibrils) and hemodynamics

Front 13

What is the etiology of Calcific Aortic Stenosis

Back 13

Etiology undetermined

Theories:
(1) relates to lipid uptake in atherosclerosis
(2) impaired nionic calcium regulation
(3) impaired regulation of noncollagenous ECM proteins (osteopontin)

Front 14

Morphology of MVP

Back 14

1. Intercordal ballooning of the mitral leaflets or portions of the leaflet
2. Leaflets are enlarged and thickened
3. Annular dilation is present (absent in insufficiency d/t other causes) --> MI
4. myxomatous changes may occur seconary to other conditions

**Tricuspid valve is affected in 20-40% of cases

Front 15

Anatomic complications of MVP

Back 15

1. linear fibrous thickening of the left ventricular endocardium
2. fibrous thickening of the valve leaflets
3. thrombosis on the atrial surfaces of the leaflets
4. thickening of the mural endocardium of the left ventricle or atrium
5. focal calcifications at the base of posterior mitral leaflet

Front 16

Clinical features of MVP

Back 16

1. most pts are asymptomatic
2. 3% pts develop complications

Complications include:
-infective endocarditis
-mitral insufficiency (leaflet deformity or rupture of chordae)
-strok or other systemic infarct d/t embolic complications
-arrhythmias
**Risk for complication >er in older men, pts with arrhythmias or MR

Front 17

Define rheumatic fever and rheumatic heart disease

Back 17

Multisystem inflammatory disease

- an acute, hypersensitivity related, immunologically mediated disease
-follows group A streptococcal pharyngitis
-has chronic valvular implications

Front 18

Morphology of Rheumatic Heart Disease

Back 18

can involve all layers of the heart

ACUTE Rheumatic Fever:
Aschoff bodies (area of fibrinoid nerosis and reactive histiocytes)
pancarditis, valvular vegetations
Anitschkow cells or caterpillar cells (MACs)
Aschoff giant cells (multinucleated giant cells)

CHRONIC:
Valvular thickening, shortening and thickening of chordae tendinae, commissural fusion
--> Left atrial enlargement and mural thrombosis
--> pulmonary vascular and parenchymal changes

Front 19

Valves most often affect in RHD

Back 19

1. MC Mitral (MS)
2. Aortic - stenosis, insufficiency

Mitral valve alone 65-70%
Mitral and aortic valve 25%

Front 20

Pathogenesis of RHD

Back 20

Cross-reactivity (mimicry) of antigens in M proteins of group A streptococcus and heart proteins

(Type II hypersensitivity reaction)

Front 21

Major manifestations of RHD

Back 21

FEVERSS:
Fever
*Erythema marginatum of the skin
Valvular damage
ESR inc.
*Red-hot large joints (migratory polyarthritis)
*Subcutaneous nodules
*Sydneham chorea

*Carditis

Front 22

Diagnosis and Jones criteria of RHD

Back 22

(1) Known group A, B-hemolytic streptococcal infection and two of the major manifestations
OR
(2) One major and two minor manifestations (fever,arthralgia, elevated acute phase reactants)

ARF is a consequence of pharyngeal infection with group A, B-hemolytic Strep while RHD is a late sequele

Front 23

Who gets Acute Rheumatic fever and when?

Back 23

--is a Usually 10 days->6weeks after infection

--3% of pts with Group A Strep pharyngitis

--Most often in children betwen ages 5 and 15 (20% of cases in middle to late life)

Front 24

How do you detect Acute Rheumatic fever?

Back 24

Detection of antibodies to strep enzymes
a. Streptolysin O
b. DNAse B

Front 25

Clinical Manifestations of Acute Rheumatic Fever

Back 25

(1) Carditis and migratory polyarthritis (adults)
(2) Fever
(3) Pericarditis - Pericardial friction rub, weak heart sounds
(4) tachycardia
(5) arrhythmias
(6) Cardiac enlargement with mitral valve insufficiency

**Susceptible to reactivation and worsening of the disease following subsequent pharyngal infection

Front 26

Clinical Manifestations of the organization phase of ARF (chronic)

Back 26

May manifest years following initial attack

(1) Fibrous pericarditis
(2) Thromboembolisms
(3) Arrhythmias
(4) Infective endocarditis

Front 27

Define Infective Endocarditis

Define Acute IE

Back 27

Infection of endothelium of heart (including, but not limited to the valves)

Acute BE - infection of NORMAL valves with a virulent organism (S. aureus)- 10-20% of cases

Front 28

Define Subacute Infective Endocarditis

Back 28

Infection of native, previously DAMAGED or congenitally abnl valve with a less virulent organism streptococcus viridans (50-60% of cases)
--Sequele of dental procedures
--Smaller vegetations
--Less valvular destruction than acute form

Microscopic:
Granulation tissue at base
Fibrosis
Calcification
Chronic inflammatory infiltrate

Front 29

Other organisms that can cause Infective Endocarditis

Back 29

(1) Enterococci
(2) HACEK group of bacteria (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella)
(3) Gram Negative bacteria
(4) Fungi
(5) other sourcs - from gut, oral cavity, trivial injury

**Blood cultures may be sterile in 10% of cases

Front 30

Predisposing factors to Infective Endocarditis

Back 30

(1) Abnormal valve:
high risk: prior endocarditis, rheumatic valvular disease, aortic or mitral valve disease, prosthesis

(2) Abnormal risk of systemic infection, bacteremia: IVDA, indwelling venous catheters, poor dentition, hemodialysis, diabetes mellitis

Front 31

Morphology of Infective Endocarditis

Back 31

(1) Both acute and subacute form s have bulky, friable destructive valvular vegetations
(2) Vegetations contain: fibrin, inflammatory cells, bacteria, other organisms
(3) Aortic and Mitral valves (are most often affected (IV drug abuse also associated with right-sided lesions)
(4) Ring abscesses
(5) Fungal endocarditis vegetations are usually large

Front 32

Complications of Infective Endocarditis

Back 32

(1) Systemic emboli
(2) Emboli produce septic infarts in kidney, brain, myocardium
(2) glomerulonephritis
(3) Microemboli produced features:
-petechiae (conjuntiva, palate), splinter hemorrhages, Janeway lesions, Osler nodes, Roth spots
(4) Cardiac: valvular regurgitation +/- thrill (fenestrated valve or ruptured chordae), pericardial friction rub)
(5) Abdomen: tender splenomegaly
(6) Glomerulonephritis

Front 33

Clinical features of Infective Endocarditis

Back 33

Symptoms may be general
(1) fever
(2) nonspecific fatigue
(3) weight loss

Acute endocarditis
(1) rapidly developing fever, chills, weakness, lassitude
(2) Immunologically-mediated Renal disease: d/t entrapped antigen-antibody complexes -->
-hematuria
-albuminuria
-renal failure
(3) Murmurs in 90% of cases, left-sided lesions

Front 34

Duke criteria - pathological findings of IE

Back 34

Major:
(1) Sustained bacteremia by an organism known to cause IE--> Demonstrate with (+)BC, histologic finding in: -active lesion,-intracardiac abscess, -embolus from vegetation
(2) Endocardial involvement - document by: (+) Echocardiog: valve or implant vegetation
(3) New valvular regurgitation

Minor:
(1) Predisposing condition: heart lesion, IV drug abuse
(2) Fever
(3) Vascular phenomena (emboli, mycotic aneurysms, Janeway lesions)
(4) Immune phenomena ((+) RF, GN, Osler's nodes, Roth spots)

**Multiple blood cultures necessary for diagnosis

Front 35

Clinical features of Infective Endocarditis using the Duke criteria (clinical findings)

Back 35

(1) Persistent bacteremia: fever, anorexia, weight loss, night sweats, fatigue
(2) Valvular or perivalvular infection: new murmur, CHF, conduction abnormalities
(3) Septic emboli - systemic or pulmonary emboilism, mycotic aneurysm, MI (CA embolism)
(4) Immune complex phenomena: arthritis, GN, (+) RF, Inc. ESR

Bacteria FROM JANE:
Fever
Roth's Spots (retinal hemorrhage + pale center)
Osler's nodes (tender digital nodules)
Murmur
Janeway lesions (septic emboli---> nontender, hemorrhagic macules on palms or soles)
Anemia
Nail-bed hemorrhage (splinter hemorrhages on nail bed)
Emboli

Front 36

Define Nonbacterial Thrombotic Endocarditis (NTBE)

Back 36

Small, sterile vegetations on valve leaflets

Front 37

Who gets NTBE?

Back 37

debilitated patients (cancer, sepsis)

Front 38

Complications of NTBE

Back 38

Embolization and infarction in multiple organs

Front 39

Morphology of NTBE

Back 39

1. sterile, single or multiple nondestructive vegetations

2. occurs along lines of closure of the leaflets or cusps

3. thrombus w/out accompanying inflammation or induced valvular damage

4. with time, organization with strands of fibrous tissue

Front 40

Pathogenesis of NTBE

Back 40

1. Related to HYPERCOAGULABLE STATE with systemic activation of coagulation cascade

2. Fequently accompanies pulmonary emboli and venous thrombosis (migratory thrombophlebitis or Trousseau syndrome)

3. Endocardial trauma due to indwelling catheters - usually right sided valvular lesions

Front 41

Associations of NTBE

Back 41

Associated with malignancies
-mucinous adenocarcinoma
-Acute promyelocytic leukemia

Other relationships
-hyperestrogenic states
-extensive burns
-sepsis

Front 42

Define NBTE Type II - Endocarditis of systemic lupus erythematosis
Libman-Sacks Disease

Back 42

Mitral and aortic vavlvulitis

Small, sterile vegetations that rarely embolize, rarely cause problems
-undersurface of valve
valvular endocardium
-chordae tendinae
-mural endocardium of atria or ventricles

Valves show fibrinouid necrosis that become fibrotic and deformed

Development of hematoxylin bodies

Accelerated coronary atherosclerosis

Front 43

Complications of artificial valves

Back 43

1. Periprosthetic hemorrhage
2. Thromboembolism
3. Infective endocarditis
4. Structural deterioration (calcification and tering of valve leaflets)
5. Dehiscence of suture lines
6. damage to blood cells with hemolysis
7. mechanical obstruction to blood flow

Front 44

Describe the thromboembolic complications of artificial valves

Back 44

Obstruction of vavle function

Distant thromboemboli

Front 45

Describe how IE d/t artificial valves causes complications

Back 45

IE on artificial heart valves are located at prosthetic-tissue interface to cause a RING ABSCESS

Direct involvement of prosthetic valve cusps with PARAVALVULAR LEAK

Front 46

What is the bacteria involved in IE d/t artificial heart valves?

Back 46

Staph aureus

Staph epidermidis

Streptococcus

Fungi