This document discusses various types of valvular heart diseases including stenosis, insufficiency, and combinations of the two. Specific conditions covered include calcific aortic stenosis caused by age-related degeneration, myxomatous mitral valve prolapse, rheumatic fever and rheumatic heart disease, infective endocarditis, and nonbacterial thrombotic endocarditis. The morphology, pathogenesis, clinical features, and diagnostic criteria for each condition are described in detail.

1. Valvular Heart Diseases
By
Dr.jawhar
Lecture 4

2. Valvular Heart Diseases
 Include: stenosis, insufficiency (regurgitation or
incompetence), or both.
 Stenosis is failure of a valve to open
completely, thereby impeding forward flow.
 Insufficiency, in contrast, results from failure
of a valve to close completely, thereby allowing
reversed flow.
 Valvular abnormalities may be caused by
congenital disorders , or by acquired diseases.

3. Valvular degeneration caused by calcification:
Calcific Aortic Stenosis:
It is the consequence of calcification owing to
progressive and advanced age-associated
"wear and tear“ injury
Morphology:
The morphologic hallmark is heaped-up calcified masses
within the aortic cusps.
( a heavily calcified aortic valve removed at the time of surgical valve replacement )

4. Clinical Features:
 Cardiac output is maintained by development of
concentric left ventricular (pressure overload)
hypertrophy.
 The hypertrophied myocardium tends to be
ischemic and angina pectoris may appear.
 There may be impairment of both systolic and
diastolic myocardial function, with symptoms of CHF.

5. Mitral Annular Calcification:
 Degenerative calcific deposits in fibrous ring
(annulus) of mitral valve.
 Generally does not affect valvular function.
 However, it may lead to:
o regurgitation by interfering with systolic contraction
of mitral valve ring.
o stenosis by impairing opening of mitral leaflets.
o arrhythmias and occasionally sudden death by
calcium deposits penetrating deeply and impinge on
atrioventricular conduction system.

6. Mitral annulus calcification: pathology specimen
This autopsy specimen demonstrates thickened mitral valve leafelts, with marked stenosis.
The mitral annulus calcification is seen as pale white 'lumps' under the endothelium around
the margins of the valve

7. Myxomatous degeneration of mitral valve
(mitral valve prolapse ):
 One or both mitral leaflets are "floppy" and
prolapse, and balloon back into left atrium during
systole.
 Most often in young women.
Morphology:
 Ballooning of mitral leaflets.
 Leaflets are often
enlarged, redundant, thick, and rubbery.
 Chordae tendineae are elongated, thinned, and
occasionally ruptured.

8. This is floppy mitral valve seen from above (left).

9. Pathogenesis:
 There is developmental defect of connective tissue
proteins ( structural proteins).
 So it is a common feature of Marfan syndrome
(caused by mutation in gene encoding fibrillin-1 )
Clinical Features:
 Most patients are asymptomatic, discovered on
routine examination by presence of midsystolic click .
 When mitral regurgitation occurs, there is late
systolic or holosystolic murmur.
 A minority of patients have chest pain .

10. Rheumatic fever and Rheumatic heart diseases: :
 RF is an acute, immunologically
mediated, multisystem inflammatory disease that
occurs a few weeks following an episode of group A
streptococcal pharyngitis.
 Acute rheumatic carditis during active phase of RF
may progress to chronic rheumatic heart disease.
 Chronic valvular deformities characterized by
deforming fibrotic valvular disease (particularly
mitral stenosis)

11. Morphology:
 Acute RHD:
 Focal inflammatory lesions called Aschoff bodies
( rheumatic granuloma ).
 Aschoff bodies consist of foci of degenerated collagen
surrounded by lymphocytes , occasional plasma
cells, and plump macrophages called Anitschkow cells
(pathognomonic for RF).
 Anitschkow cells have abundant cytoplasm and
central round-to-ovoid nuclei in which chromatin is
disposed as a central slender wavy ribbon (hence
designation "caterpillar cells").
 Some of larger macrophages become multinucleated
to form Aschoff giant cells.

14.  Aschoff bodies may be found in any of three layers of
heart ( pericardium, myocardium, or endocardium )
hence the lesion is called pancarditis.
 Involvement of endocardium and left-sided valves
results in fibrinoid necrosis within cusps or along
chordae tendineae.
 On which sit small (1 to 2 mm) vegetations (verrucae)
along lines of closure.
 These warty projections (verrucae) arise from
precipitation of fibrin at sites of erosion, related to
underlying inflammation and collagen degeneration.

16.  Chronic RHD:
 Characterized by organization of acute inflammation
and subsequent fibrosis.
 Valvular leaflets become thickened and retracted.
 Microscopically: diffuse fibrosis and
neovascularization that obliterate the originally
avascular leaflet architecture.
In chronic rheumatic mitral valvulitis the valve leaflets and chordae tendineae
are thick, rigid, and interadherent.

17. Pathogenesis:
 Acute rheumatic fever is a hypersensitivity reaction
induced by group A streptococci.
 Antibodies directed against M proteins of certain
strains of streptococci, cross-react with glycoprotein
antigens in heart, joints, and other tissues.
 The onset of symptoms 2 to 3 weeks after infection
and the absence of streptococci from the lesions
support the concept that RF results from an immune
response against the offending bacteria.

18. Clinical Features:
 RF is characterized by major manifestations:
(1) Migratory polyarthritis of large joints.
(2) Carditis.
(3) Subcutaneous nodules.
(4) Erythema marginatum of skin.
(5) Sydenham chorea ( neurologic disorder with
involuntary purposeless, rapid movements ).
 The diagnosis is established by so-called Jones
criteria: presence of two major manifestations, or
one major and two minor manifestations (
fever, arthralgia, or elevated blood levels of acute
phase reactants-CRP).

19.  Acute RF appears most often in children between
ages 5 and 15 years.
 20% of first attacks occur in middle or later life.
 Although pharyngeal cultures for streptococci
are negative by the time the illness begins.
 Antibodies to one or more streptococcal enzymes
such as (streptolysin O and DNAse B) are present
and can be detected in sera of most patients.

20. INFECTIVE ENDOCARDITIS (IE ):
 Characterized by colonization or invasion of
heart valves or endocardium by a microbe.
 Leading to formation of bulky friable vegetations
composed of thrombotic debris and organisms.
 Often associated with destruction of underlying
cardiac tissues.
 Although fungi, rickettsiae (Q fever), and chlamydiae
may be responsible for these infections, most cases
are bacterial (bacterial endocarditis).

21. Etiology and Pathogenesis:
 Classified into acute and subacute forms:
o Acute endocarditis: destructive infection of
previously normal heart valve with a highly virulent
organism (S. aureus ) as in intravenous drug abusers.
o Subacute endocarditis: organisms of low virulence
(Streptococcus viridans ) cause infection in
previously deformed valves.
 Prosthetic valve endocarditis is caused by
coagulase-negative staphylococci ( S. epidermidis).

22. Morphology:
 In both subacute and acute forms:
friable, bulky, destructive vegetations containing
fibrin, inflammatory cells, and bacteria or other
organisms are present on heart valves .
 The aortic and mitral valves are most common sites
of infection
 The vegetations may be single or multiple and
may involve more than one valve.
 Vegetations sometimes erode into underlying
myocardium to produce an abscess cavity (ring
abscess).

23.  Fungal endocarditis cause large vegetations than
does bacterial infection.
 Systemic emboli may occur because of friable nature
of vegetations, and may cause infarcts in
brain, kidneys, myocardium, and other tissues.
 Because embolic fragments contain large numbers
of virulent organisms, abscesses often develop
at sites of such infarcts (septic infarcts).
 With time: fibrosis, calcification, and chronic
inflammatory infiltrate may develop.

24. Mitral vegetation in a 78-year-old man with infective endocarditis.
Intraoperative photograph shows a large vegetation (arrow) adhering to
posterior mitral leaflet (arrowhead).

25. Diagnostic Criteria for Infective Endocarditis
Pathologic Criteria:
Microorganisms, demonstrated by culture or histologic examination, in a vegetation, embolus from a
vegetation, or intracardiac abscess.
Clinical Criteria:
Major:-
Positive blood culture(s) indicating characteristic organism.
Echocardiographic findings ; including valve-related or implant-related mass or abscess, or
partial separation of artificial valve.
New valvular regurgitation.
Minor:-
Predisposing heart lesion or intravenous drug use.
Fever.
Vascular lesions ; including arterial petechiae, subungual/splinter hemorrhages , emboli, septic infarcts,
mycotic aneurysm, intracranial hemorrhage, Janeway lesions.
Immunologic phenomena ; including glomerulonephritis, Osler nodes, Roth spots, rheumatoid factor.
Microbiologic evidence ; including single culture showing uncharacteristic organism.
Echocardiographic findings consistent with but not diagnostic of endocarditis ; including new valvular
regurgitation, pericarditis.

26.  Diagnosis by Duke Criteria requires pathologic
or clinical criteria.
 If clinical criteria are used: 2 major, or
1 major + 3 minor, or 5 minor criteria .
 Janeway lesions: small erythematous lesions on
palms and soles.
 Osler nodes: small subcutaneous nodules in pulp
of digits.
 Roth spots: oval retinal hemorrhages with pale
centers.
 Prevention of IE : by prophylactic antibiotics in
patient with cardiac anomaly or artificial valve who
have a dental, surgical, or other invasive procedure.

28. The Roth Spot Subungual/splinter hemorrhages

29. Nonbacterial Thrombotic Endocarditis (NBTE):
 characterized by deposition of small masses
(1 to 5 mm) of fibrin, platelets, and other blood
components on leaflets of cardiac valves.
 In contrast to vegetations of IE, valvular lesions of
NBTE are nondestructive, sterile (do not contain
microorganisms).
 NBTE is often encountered in debilitated
patients, such as those with cancer or sepsis (hence
previously termed marantic endocarditis).
 NBTE may producing emboli and resultant infarcts
in brain, heart, or elsewhere.