2. Hypertensive Heart Disease
SYSTEMIC (LEFT-SIDED) HYPERTENSIVE HEART
DISEASE:
Criteria for diagnosis :
(1) left ventricular hypertrophy ( concentric)
(2) history or pathologic evidence of hypertension.
Asymptomatic and suspected only by ECG or
Echocardiographic indications of left ventricular
enlargement.
3. Atrial fibrillation (owing to left atrial enlargement),
or C.H.F with cardiac dilation, or both.
Effective control of hypertension can prevent or
lead to regression of cardiac hypertrophy and
its associated risks.
Morphology:
Left ventricular hypertrophy .
Left ventricular wall thickness may exceed 2 cm
and heart weight may exceed 500 gm.
4. Microscopically:
o The earliest change is increase in transverse
diameter of myocytes.
o At more advanced stage cellular and nuclear
enlargement becomes more irregular with
variation in cell size , and interstitial fibrosis.
5. PULMONARY (RIGHT-SIDED) HYPERTENSIVE HEART
DISEASE (COR PULMONALE):
Right ventricular ( hypertrophy, dilation, and failure )
secondary to pulmonary hypertension caused by
disorders of lungs or pulmonary vasculature .
Those caused by diseases of left side of heart, or
congenital heart diseases are excluded.
7. Cor pulmonale may be acute or chronic,
depending on suddenness of development
of pulmonary hypertension:-
Acute cor pulmonale: can follow massive
pulmonary embolism.
Chronic cor pulmonale: usually secondary to
prolonged pressure overload caused by
obstruction of pulmonary arteries or arterioles.
8. Morphology:
Acute cor pulmonale: marked dilation of right
ventricle without hypertrophy.
Chronic cor pulmonale: right ventricular wall
thickens up to 1.0 cm or more, and may even
approximate that of left ventricle.
9. Cardiomyopathies:
Heart disease resulting from a primary
abnormality in myocardium.
Three patterns:
o Dilated cardiomyopathy.
o Hypertrophic cardiomyopathy.
o Restrictive cardiomyopathy.
The dilated form is most common (90% of cases),
and the restrictive is least prevalent.
10. DILATED CARDIOMYOPATHY:
Also called congestive cardiomyopathy.
Causes:
Familial (genetic) : autosomal dominant.
Toxicities: chronic alcoholism.
Myocarditis.
pregnancy-associated nutritional deficiency.
Immunologic reaction.
In some patients: unknown ( idiopathic ).
11. Morphology:
Heart is large and flabby, with dilation of all
chambers.
Mural thrombi are common and may be a source
of thromboemboli.
Mitral or tricuspid regurgitation results from
ventricular chambers dilation (functional
regurgitation).
Muscle cells are attenuated, stretched, and irregular.
Interstitial and endocardial fibrosis of variable
degree is present
12. Clinical Features:
Occur at any age, but usually between 20 and 50 y’s.
Slowly progressive signs and symptoms of CHF
such as shortness of breath, and easy fatigability.
Secondary mitral regurgitation and abnormal
cardiac rhythms are common.
Death is due to progressive cardiac failure or
arrhythmia and can occur suddenly.
Embolism from dislodgment of an intracardiac
thrombus may occur.
Cardiac transplantation is only hope.
13. HYPERTROPHIC CARDIOMYOPATHY :
characterized by: myocardial hypertrophy,
abnormal diastolic filling, and in one third of cases
intermittent ventricular outflow obstruction.
Morphology:
Massive myocardial hypertrophy without
ventricular dilation.
disproportionate thickening of ventricular septum
as compared with free wall of left ventricle (ratio
greater than 3:1) termed asymmetrical septal
hypertrophy.
14. On cross-section: ventricular cavity has
"banana-like" configuration by bulging of
ventricular septum into lumen.
Microscopically:
(1) Extensive myocyte hypertrophy with
transverse myocyte diameters greater than 40 µm
(normal 15 µm).
(2) Haphazard disarray of myocytes.
(3) Interstitial and replacement fibrosis.
16. Pathogenesis:
H.C.M caused by a mutation in any one of
several genes that encode proteins that are
part of sarcomere.
Sarcomere is the contractile unit of cardiac and
skeletal muscle.
Most cases are familial and pattern of transmission
is autosomal dominant with variable expression.
Remaining cases appear to be sporadic.
17. Mutations are found in at least 12 sarcomeric genes.
Including: β-myosin heavy chain (β-MHC),
cardiac troponinT, α-tropomyosin, and
myosin-binding protein C (MYBP-C).
Of these, mutation in β-MHC gene is most common .
18. Clinical Features:
Impaired diastolic filling of massively
hypertrophied left ventricle.
25% of patients have dynamic obstruction to
left ventricular outflow.
Limitation of cardiac output and secondary
increase in pulmonary venous pressure cause
exertional dyspnea.
Harsh systolic ejection murmur, caused by
ventricular outflow obstruction .
19. Owing to massive hypertrophy: myocardial ischemia
commonly results, even in absence of concomitant
CAD, and thus anginal pain is frequent.
The major clinical problems in H.C.M are:
o atrial fibrillation with mural thrombus formation ,
and possibly embolization.
20. o infective endocarditis of mitral valve.
o intractable cardiac failure.
o ventricular arrhythmias , and sudden death.
Hypertrophic cardiomyopathy is one of the most
common causes of sudden, otherwise unexplained,
death in young athletes.
21. RESTRICTIVE CARDIOMYOPATHY :
Decrease in ventricular compliance, resulting in
impaired ventricular filling during diastole.
The contractile (systolic) function of left ventricle
is usually unaffected.
Idiopathic ; or associated with distinct diseases
that affect myocardium: radiation fibrosis,
amyloidosis, sarcoidosis, or metastatic tumor.
22. Morphology:
Ventricles are of normal size or slightly enlarged.
Cavities are not dilated, and myocardium is firm.
Microscopically: patchy or diffuse interstitial fibrosis,
which can vary from minimal to extensive.
amorphous deposits of pale pink material between myocardial fibers.
This is characteristic for amyloid. Amyloidosis is a cause for restrictive cardiomyopathy.
23. Valvular Heart Disease:
Valvular involvement by disease causes 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 a variety of acquired diseases.
The most important causes of acquired heart valve
diseases are:
24. VALVULAR DEGENERATION CAUSED BY CALCIFICATION :
due to calcific deposits (composed of calcium phosphate
mineral).
The most frequent calcific valvular diseases are:-
Calcific Aortic Stenosis:
It is the consequence of calcification owing to progressive
and advanced age-associated "wear and tear“ injury
Morphology:
The morphologic hallmark of calcific aortic stenosis is
heaped-up calcified masses within the aortic cusps.
( a heavily calcified aortic valve removed at the time of surgical valve replacement )
25. Clinical Features:
obstruction to left ventricular outflow leads to
gradually increasing pressure gradient across the
calcified valve.
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.
such patients require prompt relief of obstruction by
surgical valve replacement.
26. Mitral Annular Calcification:
Degenerative calcific deposits can develop in fibrous
ring (annulus) of mitral valve.
The process generally does not affect valvular function.
however, it may lead either 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 sufficiently deeply to impinge on
atrioventricular conduction system.
27. 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
28. MYXOMATOUS DEGENERATION OF MITRAL VALVE
(MITRAL VALVE PROLAPSE):
one or both mitral leaflets are "floppy" and prolapse, or
balloon back into left atrium during systole.
most often in young women.
Usually an incidental finding on physical examination.
may lead to serious complications in minority of cases.
Morphology:
ballooning (hooding) of mitral leaflets.
leaflets are often enlarged, redundant, thick, and
rubbery.
Chordae tendineae are elongated, thinned, and
occasionally ruptured.
29. Slide Description: This is floppy mitral valve seen from above (left).
Note also the thickened, distorted tricuspid valve, probably
rheumatic in origin.
30. Pathogenesis:
there is developmental defect of connective tissue,
possibly systemic.
So it is a common feature of Marfan syndrome (caused
by mutations in gene encoding fibrillin-1 )
Clinical Features:
Most patients are asymptomatic, discovered on routine
examination by presence of a midsystolic click .
when mitral regurgitation occurs, there is a late systolic
or sometimes holosystolic murmur.
A minority of patients have chest pain mimicking
angina, dyspnea, and fatigue.
31. RHEUMATIC FEVER AND RHEUMATIC HEART DISEASE :
Rheumatic fever ( 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 (RHD).
The most important consequence of RV is chronic
valvular deformities, characterized principally by
deforming fibrotic valvular disease (particularly mitral
stenosis)
32. Morphology:
During acute RF, focal inflammatory lesions are found
within heart called Aschoff bodies ( rheumatic
granuloma ).
Aschoff bodies consist of foci of degenerated collagen
surrounded by lymphocytes (primarily T cells),
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 the chromatin is
disposed as a central, slender, wavy ribbon (hence the
designation "caterpillar cells").
Some of larger macrophages become multinucleated to
form Aschoff giant cells.
35. 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 irregular, warty projections (verrucae ) arise from
precipitation of fibrin at sites of erosion, related to
underlying inflammation and collagen degeneration.
37. Chronic RHD is characterized by organization of acute
inflammation and subsequent fibrosis.
valvular leaflets become thickened and retracted,
causing permanent deformity.
Microscopically there is diffuse fibrosis and often
neovascularization that obliterate the originally
avascular leaflet architecture.
In chronic rheumatic mitral valvulitis the valve leaflets and chordae tendineae are
thick, rigid, and interadherent.
38. 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.
39. 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:
the presence of two of major manifestations, or one
major and two minor manifestations ( fever, arthralgia,
or elevated blood levels of acute phase reactants-CRP).
40. Acute RF appears most often in children between
ages 5 and 15, but about 20% of first attacks occur
in middle to 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.
41. INFECTIVE ENDOCARDITIS (IE ):
is 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
have been responsible for these infections, most cases
are bacterial (bacterial endocarditis).
42. Etiology and Pathogenesis:
classified on clinical grounds into acute and subacute
forms.
Acute endocarditis: destructive infection of a previously
normal heart valve with a highly virulent organism
(S. aureus ) as in intravenous drug abusers.
Subacute endocarditis: organisms of low virulence
(Streptococcus viridans )can cause infection in
a previously deformed valves.
Prosthetic valve endocarditis is caused most commonly
by coagulase-negative staphylococci ( S. epidermidis).
43. Morphology:
In both subacute and acute forms friable, bulky, and
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).
Fungal endocarditis tends to cause large vegetations
than does bacterial infection.
44. Systemic emboli may occur because of friable nature of
vegetations, and may cause infarcts in brain, kidneys,
myocardium, and other tissues.
Because the embolic fragments contain large numbers of
virulent organisms, abscesses often develop at sites of
such infarcts (septic infarcts).
With passage of time, fibrosis, calcification, and chronic
inflammatory infiltrate may develop.
45. Mitral vegetation in a 78-year-old man with infective endocarditis.
Intraoperative photograph shows a large vegetation (arrow) adhering to posterior
mitral leaflet (arrowhead).
46. 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.
47. Diagnosis by Duke Criteria, requires either pathologic or
clinical criteria; if clinical criteria are used, 2 major, or 1
major + 3 minor, or 5 minor criteria are required for
diagnosis.
Janeway lesions are small erythematous lesions on
palms and soles.
Osler nodes are small subcutaneous nodules in pulp of
digits.
Roth spots are oval retinal hemorrhages with pale
centers.
Prevention of IE is done by prophylactic use of
antibiotics in patient with cardiac anomaly or artificial
valve who is about to have a dental, surgical, or other
invasive procedure.
50. Nonbacterial Thrombotic Endocarditis (NBTE):
NBTE is 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, the valvular lesions of
NBTE are nondestructive , sterile and 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.