The cardiovascular system

1. The Cardiovascular System
Part 2
By
Dr. Varughese George
Department of Pathology

2. Topics
Rheumatic Heart Disease
Infective Endocarditis

3. RHEUMATIC HEART DISEASE
• Post-streptococcal immune-mediated
inflammatory disease affecting heart and
extra-cardiac sites e.g. joints, skin, brain.
• Acute rheumatic Pancarditis - manifestation
during the active phase of RF.
• Leads to chronic rheumatic heart disease
(RHD)
of which valvular abnormalities are key
manifestations

4. ACUTE RHEUMATIC FEVER
Redness & swelling
of throat & tonsils;
Beefy, swollen, red
uvula; Soft palate
petechiae
(“doughnut
lesions”)
Tonsillopharyngeal
erythema &
exudatesPrevious H/O sore
throat: fever, white
draining patches on
the throat & swollen
or tender lymph
glands in the neck

6. vegetations Aschoff body pericarditis
Strep throat
Antibody
production
Antibody cross-reaction
with heart
PATHOGENESIS

7. RHEUMATIC HEART DISEASE
The disease passes into two phases
ACUTE PHASE:
o acute rheumatic pancarditis (inflammation of
endocardium, myocardium and pericardium)

8. FIBRINOUS PERICARDITIS –
BREAD & BUTTER APPEARANCE
 PERICARDITIS:
“bread and butter” appearance, due to
fibrinous inflammation

9.  MYOCARDITIS:
A characteristic lesion of acute
rheumatic fever/ RHD is Aschoff
body:
 Consists of a focus of fibrinoid necrosis
(representing the site of antigen –
antibody reaction) surrounded by
activated histiocytes and lymphocytes.
The histiocytes may be mononuclear or
multinuclear, and are referred to as
Anitschkow's or Aschoff cells
 These cells have abundant cytoplasm
and central round-to-ovoid nuclei in
which the chromatin is disposed in a
central, slender, wavy ribbon
("caterpillar cells").
 Larger macrophages become
multinucleated to form Aschoff giant
cells
An Aschoff body (granulomatous stage) in
the myocardium. Inbox shows Anitschkow
cell in longitudinal section (LS) with
caterpillar-like serrated nuclear chromatin,
while cross section (CS) shows owl-eye
appearance of central chromatin mass and
perinuclear halo.

10.  ENDOCARDITIS:
• Mostly involves mitral
and aortic valves.
• Edema, inflammation and
fibrin deposits on valve
leaflets (vegetations) along
lines of closure.
• MacCallum plaques : left
arterial endocardial
thickening.

11. RHEUMATIC HEART DISEASE
CHRONIC PHASE:
Acute changes may resolve completely or
progress to scarring and development of
chronic valvular deformities many years after
the acute disease.

12. CHRONIC VALVULAR HEART DISEASE
• Mitral and aortic valvular fibrosis –
– Valve thickening and calcification.
– Fusion of the valve commissures.
– Chordae tendinae are short, thickened,fused and
fibrosed.

13. CHRONIC VALVULAR HEART DISEASE
Aortic
valve
stenosis
Mitral stenosis with
diffuse fibrous
thickening and
distortion of the valve
leaflets – button hole
appearance
Distortion of the
cusps with
commissural fusion

14. Other cardiac complications
1. Subacute bacterial endocarditis
2. Arrhythmia
3. Chronic heart failure

15. Topics
Rheumatic Heart Disease
Infective Endocarditis

16. Infective Endocarditis
• Infection of the cardiac valves or mural
surface of the endocardium, resulting in the
formation septic vegetations (thrombi)

17. ETIOLOGICAL FACTORS
1. Turbulent blood flow by haemodynamic
stress causes damage to the endothelium
,favouring the formation of platelet
thrombi.
2. Bacteremia delivers the organisms to the
endocardial surface
3. Adherence of the organisms to the
endocardial surface
4. Eventual invasion of the valvular leaflets

18. CLASSIFICATION
• Acute
– Affects normal heart valves.
– Mural endocardium may be
also affected.
– Affected valve and mural
endocardium show acute
suppurative inflammation +
vegetations.
– Rapidly destructive
– Commonly Staphylococcal
infection (Staphylococcus
aureus)
– If not treated, usually fatal
within 6 weeks
• Subacute
– Often affects damaged heart
valves{Rheumatic valvulitis,
congenitally abnormal valves,
prosthetic valves}
– Indolent nature
– Commonly streptococcal
infection (Streptococcus
viridens)
– If not treated, usually fatal by
one year

19. Summary of salient features of vegetations in different endocarditis

20. GROSS EXAMINATION
The vegetations are
• variable in size – may be flat, filiform,
fungating or polypoid.
• grey to greenish
• irregular
• typically friable.
• The vegetations are mainly found on
the valves of left heart, most
frequently on
– the atrial surface of mitral valve
– ventricular surface of aortic valve
– combined mitral and aortic valvular
involvement.
Vegetations on valves in acute bacterial
endocarditis.
The chambers and valves of the left heart
are opened up. The mitral valve on its atrial
(superior) surface show irregular, soft,
elevated, greyish areas of varying size
(arrow).

21. MICROSCOPICAL EXAMINATION
The vegetations consist of 3
zones:
• Outer layer or cap composed
of eosinophilic material of
fibrin and platelets.
• Underneath is the basophilic
zone containing colonies of
bacteria in untreated cases.
• The deeper zone consists of
nonspecific inflammatory
reaction in the cusp

22. Endocarditis of the mitral valve
(subacute, caused by
Streptococcus viridens).
vegetations are denoted by
arrows.
SUB ACUTE ENDOCARDITIS

23. Complications
ACUTE IE
1. Embolic complications:
• Detached septic vegetations
leads to systemic pyemia.
2. Toxemic complications:
• Severe toxemia
SUB ACUTE IE
1. Embolic complications:
• Infarctions: in kidney, spleen and
brain, retina, heart.
• Mycotic aneurysms: mainly in cerebral
and mesenteric.
• Petechial hemorrhage: in skin, mucous
membranes and serous membranes.
• Osler’s nodules: small. tender,
intracutaneous nodules in pulps of
fingers & toes.
2. Toxemic complications:
• Moderate toxemia: fever, anemia,
clubbing of fingers, splenomegaly,
petechial hemorrhage and focal
glomerulonephritis (flea bitten kidney)