PATHOLOGY OF THE HEART: ISCHEMIC HEART DISEASE, CONGENITAL
HEART DISEASE. ENDOCARDIAL AND VALVULAR DISEASES.
MYOCARDITIS AND CARDIOMYOPATHY. TUMORS.

MANIFESTATIONS OF CARDIAC DISEASES.
1. PAIN
-ischemic pain- the most common, caused by stimulation of nerve endings by
lactic acid produced by anaerobic glycolysis
-retrosternal-may radiate to back and upper extremity
-angina pectoris- is ischaemic pain induced by exercise
-pericardial pain- inflammation of pericardial cavity- causes pain that tend to
vary with respiration
2. CARDIAC ENLARGMENT
-results from dilatation of cardiac chambers or from hypertrophy of the heart
walls
-diagnosis-electrocardiography and radiography
-documentation at autopsy-done by measuring the thickness of myocardium
-right ventricle thickness exceeding 5 mm
-and left ventricle thickness exceeding 15 mm- constitutes hypertrophy
3. ARRHYTHMIA-abnormal cardiac rhytm
-normal cardiac contraction is initiated in sino-atrial node and conducted to
atrioventricular node in HIS-PURKINJE system
-the patients are aware of arrhytmias- complain of palpitations and ”missed beats”
-cause is ischemia, less commonly drugs, inflammation of myocardium, etc.
4. CARDIAC FAILURE- inability to maintain a cardiac output needed despite
normal venous return
-clinical changes depend on-whether the left side or right side is predominantly
affected
-whether the failure is acute or chronic
 left-sided heart failure
1-acute cardiac arrest-leads to sudden death
-the causes include ventricular fibrillation or no contraction- results in cerebral
ischemia- death within few minutes
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2-acute severe decrease in output-leads to cardiogenic shock- decreased output
causes tachycardia and vasoconstriction- tissue hypoxia, hypoxia of kidney results
in decreased urine output
-backward component of acute failure- causes acute pulmonary edema- because of
increased hydrostatic pressure in pulmonary capillaries- transudation of fluid into
alveolar space
3-chronic heart failure-backward component is dominated by the changes within
lungs- chronic pulmonary venous congestion-fibrous thickening of interalveolar
septa-dyspnoea
-entry of RBCs into alveoli-accumulation of hemosiderin in alveolar macrophages
-brown induration of lung
 right-sided heart failure
1-acute severe decrease in output- occurs most commonly when massive pulmonary
embolus becomes impacted in and obstructs the outflow tract of right ventriclesudden death
2-cardiac tamponade- form of acute heart failure because of sudden increase in
pericardial pressure due to fluid accumulation (blood)
3-chronic heart failure-manifested clinically by systemic venous congestion
-liver is enlarged-congestion around central veins produces an appearance
resembling nutmeg, associated with fatty change due to anoxia
-peripheral edema, cyanotic induration of visceral organs, such as kidney, spleen
 ISCHEMIC HEART DISEASE (= CORONARY HEART DISEASE )
=group of closely related clinical syndromes that result from myocardial ischemia
-ischemic heart disease is a common cause of death up to about 1/3 (one
third) of all deaths in U.S.- 80% of all cardiac deaths are attributable to IHD
-Basically, an imbalance between myocardial oxygen demand and supply
could be caused by three possible mechanisms:
 1)- reduced coronary blood flow- the most common cause
severe coronary atherosclerosis superimposed by thrombosis on ruptered or
ulcerated atherosclerotic plaques- vasospasm and aggregation of platelets can
contribute to the ischemia
 2)- increased myocardial demand-due to tachycardia, myocardial hypertrophy,
etc.
 3)- diminished oxygen transport
-due to severe anaemia, - advanced lung disease
-congenital cyanotic HD
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-carbon monoxide poisoning
-cigarette smoking
 ISCHEMIC HEART DISEASE
There are four different syndromes of ischemic heart disease:
1) angina pectoris
2) myocardial infarction
3) chronic ischemic heart disease
4) sudden death
1) ANGINA PECTORIS
- characterized by attacks of chest pain or discomfort due to myocardial ischemia
- angina pectoris is caused by severe atherosclerosis, narrowing of the coronary
arteries, that can provide adequate blood supply to the myocardium at rest, but
not enough in exercise -thus an increased effort, stress, increased demand
provoke pain (administration of nitroglycerin causes a relief)
morphology:- only minor morphologic changes, such as foci of myofibrosis in the
myocardium, and focal atrophy of the myocardium, but no complete infarction
2) ACUTE MYOCARDIAL INFARCTION
“big four“ risk factors of atherosclerosis are: cigarette smoking, hypertension,
diabetes mellitus, hypercholesterolemia- the same risk factors such as those for
IM
-Myocardial infarction could be subdivided into two types with different
morphology, pathogenesis and clinical significance :
1-subendocardial- is limited to the inner one third or one half of ventricular wall
2-transmural- involving the full thickness of the heart wall
pathogenesis:
 subendocardial infarction -the subendocardium is most vulnerable to any
reduction of blood flow
-often occurs in the setting of global ischemia based on diffuse severe coronary
AS but without superimposed thrombosis- transient global borderline perfusion
made critical by an increased demand, vasospasm or hypotension
-differs clinically from the transmural one (different ECG picture, different level
of risk of complications
 transmural infarction- vast majority of transmural IMs are caused by
1- marked stenosis of coronary artery
2- regressive changes in atherosclerotic plaques, including fissure, rupture,
haemorrhage, oedema within the plaque
3- platelet activation and aggregation- thrombosis of coronary vessel
4- vasospasm of coronary artery
all these events contribute, any of them may prevail in an individual case
usually in IM- more branches of coronary artery are involved, but a single one may
be only affected - significant AS plaques usually occur in the proximal 2 cm of the
descending left anterior- the most common single site of occlusion
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in majority of cases of transmural infarctions- atherothrombotic occlusion
sequence of events in developing the infarction:
- intraplaque haemorrhage or rupture of atheroma initiates superimposed
occlusive thrombosis
- platelet activation contributes to build up the thrombus- fibrinolytic drugs are
administrated in order to re-perfuse the ischemic area
- phenomenon of the so-called “reflow injury“- caused by release of free toxic
radicals from leukocytes attracted to necrotic area
the ultimate size of infarction depends on
-extent, severity and duration of ischemia
- the magnitude of collateral flow
- influence of “reperfusion injury“
 MORPHOLOGY OF ACUTE MYOCARDIAL INFARCTION
-virtually all IMs involve left ventricle (including the interventricular septum)- in
rare occassions IM of left ventricle may extend to right side
grossly: occlusive thrombus can usually, but not always be identified in the
coronary artery
microscopically: the appearance of IM changes with the time of anoxia2h- no changes
3-6h- changes may be visualized by the use of histochemical techniques, such as
staining for dehydrogenases
more than 3h- early electron microscopic changes
6-8h- early light microscopic changes and after 24h- first macroscopic changes
 morphologic complications associated with IM:
- papillary muscle infarction may cause a rupture and acute insufficiency of mitral
valve
- fibrinous and fibrinohemorrhagic pericarditis
- mural thrombosis ( risk of peripheral embolism)
- rupture of the heart in the area of IM- causes massive cardiac tamponade
- chronic ventricular aneurysm may develop
3) CHRONIC ISCHEMIC HEART DISEASE
-chronic progressive coronary atherosclerosis and progressive ischemic
myocardial damage
morphology:- normal weight - may be brown atrophy
modest left ventricular dilatation
atherosclerosis of coronary arteries, and myofibrosis- patchy foci of gray-white
scars
clinical course: slowly progressive disease- serious cardiac arrhythmia or IM may
develop
4) SUDDEN CARDIAC DEATH
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= unexpected death from cardiac causes within 1-24h after the onset of acute
symptoms
-mechanism-almost always malignant arrhytmia caused by ischemia
 CONGENITAL HEART DISEASES (CHD)
Etiology:
-in most cases of CHD-no identifiable cause- they are very likely
multifactorial with genetic and environmental inputs
-in few patients, a specific cause can be identified, such as transplacental
infection of the fetus by rubeola virus (1st trimester)
or chromosomal abnormalities may be associated with CHD- high incidence of
defects of the atrioventricular valves in Down syndrome
some drugs, such as thalidomide were shown to cause severe defects in the fetus
including cardiac anomalies
fetal alcohol syndrom- due to high amounts of alcohol used during early pregnancy
 CLASSIFICATION OF CHD:
-congenital heart anomalies are of two major types- shunts and obstructions
shunts= abnormal communications between heart chambers, between large vessels
or between chambers and vessels
 Common defects are classified according to:
1- which side of the heart is involved
2- whether there is a communication (shunt) between both sides
3- in the defect with shunt, if there is a cyanosis (= a bluish colour of the
skin and mucous membranes caused by increased amount of reduced haemoglobin
in arterial blood
obstruction= typical examples include coarctation (stenosis of aorta), valvular
stenoses (partial occlusion) and atresias (complete occlusion). These do not cause
cyanosis
-according to the major functional disorders, the CHD may be classified to
three categories:
 1 ) CHD with left-to-right shunts (=CHD with late cyanosis )
- these include interventricular and septal defects and patent ductus
arteriosus
-at early stage - these anomalies are without cyanosis, but the increased
blood pressure in right side induces chronic right heart overload with pulmonary
hypertension and right ventricle hypertrophy - results in reversal of the direction
of blood flow-leads to a development of right-to-left shunt- means that
nonoxygenated blood is then shunted to the left heart-which causes “ late
cyanosis“
1. ATRIAL SEPTAL DEFECTS
-is characterized by an abnormal opening in the atrial septum that allows free communication of
blood
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- when less than 1 cm, it is well tolerated, even larger ASDs are usually not
detected until adult life, the problems appear with the reversal of the blood flow
and cyanosis and right-sided heart failure
2. VENTRICULAR SEPTAL DEFECTS
-is an abnormal opening in the ventricular septum that allows free communication between left and
right ventricles
- are among the most common CHD
 - clinical significance of ventricular septal defects (VSD) depends on the size of
defect
-large VSD are much serious with clinical manifestation in early life- strong
left-to-right shunt causes an increased blood flow- pulmonary
hypertension-small VSDs - mild left-to-right shunt does not cause changes in blood flow,
but the patients are in increased risk of infective endocarditis
- surgical correction is advocated before right heart overload and vascular pulmonary disease
develop
3. PATENT DUCTUS ARTERIOSUS
- in the fetus, the ductus arteriosus is a normal fetal vascular channel that connects the
pulmonary artery and the aorta - permitting to by-pass the inactive fetal lungs
- after the birth, the ductus closes spontaneously by muscle spasm within 1 to 2 days of
life
clinical significance:
-even large PDA are initially asymptomatic, but later they cause a
left-to-right shunt, pulmonary hypertension- reversal of blood flow, right-sided
hypertrophy and right-sided heart failure
- early surgical closure of a PDA is advocated
 2 ) CHD with right-to-left shunts (=CHD with early cyanosis)
- these include tetralogy of Fallot, truncus arteriosus and transpositions of large
heart arteries
- secondary finding in long-standing cyanotic HD induce clubbing of the fingers
and toes, hypertrophic osteopathy and polycytemia
1. TETRALOGY OF FALLOT
-is the most common cyanotic CHD
 -it is characterized by four cardinal features
-large ventricular septal defects
-dextroposed aorta overriding the ventricular septal defect
-stenosis of the pulmonary tract with RV outflow obstruction
-hypertrophy of the right ventricle
Cyanosis is present from birth-because the stenosis of pulmonary artery causes
right-to-left shunt from the very beginning (early cyanosis) -“blue babies“
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severity of clinical symptoms is directly related to the extent of RV outflow
obstruction
- mild pulmonic stenosis and large VSD produces only mild left-to-right
shunt without cyanosis
- more severe pulmonary stenosis produces a cyanotic right-to-left shunt, right-sided
hypertension appears-causing right-toleft shunt with hypoxemia, dyspnea, and cyanotic or hypoxic
symptoms- finely pulmonary hypertension appears
-with complete pulmonic obstruction, survival is permitted only by
blood flow through a patent ductus arteriosus
 prognosis is very poor without treatment-surgical repair or at least partial
correction is now possible in all cases
 treatment depends on performing the arteficial shunt in order to by-pass
pulmonary tract stenosis
2. TRANSPOSITION OF GREAT ARTERIES
-means origin of the aorta from the right ventricle and the pulmonary artery from
the right
-prognosis depends on the severity of tissue hypoxia and the ability of the RV to
maintain aortic flow, untreated-most children die within the first few months
3. TRUNCUS ARTERIOSUS
-is a developmental failure of the aorta and the pulmonary artery to separatemeans that there is a single blood vessel receiving blood from both RV and LV
-patients present with early cyanosis due to right-to-left shunting
-this anomaly has a poor prognosis
 3 ) CHD with obstruction of blood flow without cyanosis
these include coarctation of the aorta, aortic valvular stenosis and pulmonary
valvular stenosis
1. COARCTATION OF THE AORTA
=represents narrowing or stenosis of the aorta
 clinical manifestation depends on location and severity of obstructiontwo types of the coarctation of the aorta
 preductal type of coarctation - manifests early in life and may cause rapid
death
-survival depends on the ability of the ductus arteriosus to sustain blood flow to
the distal aorta and to the lower body adequately- even then- severe lower body
cyanosis- often associated with fetal RV hypertrophy and early right heart failure
 postductal type -the “adult type“ because this type of anomaly is generally
asymptomatic unless very severe untill adult life -it usually leads to hypertension in the upper extremity, but weak pulses and low
blood pressure in the lower extremities- causes arterial insufficiency
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-often claudications and coldness of the lower extremity
-collateral flow around stenosis of the aorta develops- with mammary and axillary
arteries dilatation
surgery: if untreated- life span is 40 years- death is due to aortic
dissection -proximal to coarctation, intracranial haemorrhage, or infective
endocarditis at the site of narrowing surgical resection of the affected portion of
the aorta and replacement by a prosthetic graft - prevents these complications
ACQUIRED HEART DISEASES.
ENDOCARDIAL AND VALVULAR DISEASES
among acquired valvular diseases, the most important are
1) CALCIFIC AORTIC VALVE STENOSIS
=represents 90% of acquired aortic stenoses, these are degenerative,
age-related lesions etiologically associated with AS, morphology:
grossly- calcified masses within the sinuses of Valsalvae, that cause thickening
and fibrosis of the aortic valve with narrowing of the orifice
-there may be LV hypertrophy from chronic pressure overload
clinically: CHF due to LV hypertrophy and ischemia- because the process may
cause a narrowing of proximal parts of coronary arteries
2) POSTRHEUMATIC HEART DISEASE ( RHD)
-is acquired fibrotic disorder of the heart valve associated with severe change of
function
-results from consequencies of acute rheumatic fever= is an acute nonsuppurative
inflammatory immune-mediated disease that follows 2-3 weeks after acute
streptoccocal pharyngitis
-acute bacterial infection initiates a production of antibodies that cross
react with myocardial and endocardial cells and with other cells of the bodyresulting in a process of autoimmune tissue destruction
-in acute rheumatic fever - many organs may be affected, including
 the heart- all layers may be involved
in myocardium- acute myocarditis- characterized by presence of Aschoff bodiescomposed of focal fibrinoid necrosis of collagen, scattered lymphocytes and
plasma cells and Aschoff giant epithelioid histiocytes
in the endocardium- the disease affects particularly the valves- in acute
inflammation- the involved valves show edema, endocardial damage and rheumatic
vegetations (composed of fibrin and platelets, and debris), in chronic phaserheumatic endocarditis heals by fibrosis- Mc Callum patch= focal fibrotic scar of
the free endocardium in the posterior wall of the left atrium
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-fibrosis of the affected valve- causes a narrowing of the orifice= valve
stenosis
or severe destruction of the valve-may cause rigid dilatation=valve incompetence
-the mitral valve is most commonly affected (aortic valve, less often the
valves of right heart)
 the joints - infection affects mostly large joints, tend to migrate from joint to
joint
 basal ganglia of the brain- causes so called chorea- involuntary movements
 skin lesions subcutaneous rheumatic nodules- consist of fibrinoid necrosis
surrounded by a rim of granulation inflammatory reaction
3) INFECTIVE ENDOCARDITIS
-is a disease associated with colonization of heart valves with microbes in
severe bacteriemia leads to formation of friable infected thrombi (vegetations)
and to destruction of the valve
-the incidence of IE has decreased with the availability of antibiotics
IE has traditionally been classified to two categories
acute and subacute - but these patterns now overlap due to treatment
 ACUTE INFECTIVE ENDOCARDITIS
caused by highly virulent agents that can even attack previously normal valves
-severe bacteriemia
morphology:
- heart valves are involved by large vegetations
-
cause embolic complications with metastatic abscesses in many organs
The disease typically presents as a rapidly developing fever with rigor and severe weakness
 SUBACUTE INFECTIVE ENDOCARDITIS
more common, caused by organisms with lower virulence, infection usually affects
previously damaged valves (chronic RHD, CHD, prosthetic valves, degenerative
valve diseases)
clinically low grade bacteriemia, fever. This disease tends to have a protracted
course.
morphology:
damaged valves are covered by infected thrombi (=vegetation)- consist of
collections of leukocytes, bacterial colonies, fibrin, cellular debris
- vegetations- are large, soft, friable, possible subject of embolismsystemic embolism- infarction in the brain, kidney, spleen
mycotic aneurysm= infected embolus causes weakening of the affected artery
wall- formation of the aneurysm= miliary microabscesses
clinically:
-bacteriemia- blood culture positive for bacteria
-fever-most common feature
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-splenomegaly-due to activation in chronic bacteriemia (phagocytic and
endothelial cell hyperplasia in the spleen)
-valvular dysfunction- cardiac murmurs or injury to myocardium (abscess,
perforation)
-various effects of systemic embolism -spleen, kidney, brain- including the
metastatic infections
4) NONBACTERIAL THROMBOTIC ENDOCARDITIS
-is characterized by small, bland fibrin and platelet thrombi (vegetations) loosely adherent
to valve leaflets and the line of closure of the valve, without a significant inflammation
also called “ marantic“- this characteristically occurs in the settings of prolonged
debilitating illness - chronic renal failure, cachexia, chronic sepsis
clinical significance is derived from emboli and associated with infarctions
5) MITRAL ANNULUS CALCIFICATION
=degenerative noninflammatory lesion with calcific deposits within the mitral
annulus in elderly- often associated with IHD
calcium deposits may cause arrhythmia- due to disorder of conducting pathways
MAJOR FUNCTIONAL DISORDERS OF CARDIAC VALVES
most common
(1) MITRAL STENOSIS
cause resistence of blood flow through the open mitral valve during diastole- murmur
left atrial dilatation and hypertrophy- blood tends to stay in left atrium -thrombus formation (
atrial fibrillation predispose - left atrial thrombi may cause systemic emboli- sudden death of “ball
valve thrombus“
increased pulmonary pressure
signs of chronic left heart failure ( pulmonary edema, hemorrhages, congestion)
right ventricel hypertrophy
(2) MITRAL INCOMPETENCE
in most cases due to rheumatic heart disease, usually associted with mitral stenosis- rigid valve
other causes:
in chronic ventricle failure- dilatation of mitral valve ring- results in functional mitral incompetence
rupture of papillary muscle due to acute infarction
calcification of the mitral valve ring in elderly- rare
mitral valve incompetence causes regurgitation of blood from the left ventricle to left atrium
through systole- pansystolic murmur
left ventricle volume is increased- left ventricle dilatation and hypertrophy
left atrium dilated ( accepts both pulmonary venous return and regurgitant flow )
left atrium pressure is increased
pulmonary hypertension- right ventricle hypertrophy- failure
acute mitral incompetence may develop- causes acute left ventricle heart failure ( acute pulmonary
edema)
(3) AORTIC STENOSIS
in most cases - in rheumatic heart disease ( often mitral valve involvement )
congenital defects, ascending sclerosis) due to calcification ib atheroscl. process)
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the flow through stenotic aortic opening- turbulent-systolic murmur
decreased cardiac output- hypotension, myocardial ischemia (low pressure in coronary arteries )low peripheral pulse
left ventricle hypertrophy and dilatation-left ventricle heart failure
(4) AORTIC INCOMPETENCE
most often due to rheumatic heart disease ( very often with valve disorder )
other causes-in syphilis-due to dilataion of the aorta in syphilitic aortitis
rupture of the aortic valve in infective endocariditis- most common cause of acute aortic
incompetence
regurgitation of blood from the aorta in distole- decreased diastolid blood pressure
at the same time- systolic pressure is elevated ( normal volume- regurgitant from the aorta)massive left ventricle dilatation and hypertrophy- left ventricle failure
PULMONARY AND TRICUSPIDAL VALVES- much less commonly affected
only carcinoid syndrome- has clinical significance
carcinoid tumors ( endocrine active tumors)- may produce serotonin- which promotes fibrosis of
endocardium in right-side of heart
attacks of skin flushing, nausea, vomiting, bronchospasms
MYOCARDIAL DISEASES.
-diffuse heart disease can be separated to two major groups
1) myocarditis - diffuse diseases of the heart characterized by inflammatory
reaction
2) cardiomyopathy -diffuse non-inflammatory myocardial diseases
MYOCARDITIS
=inflammatory disease of the myocardium characterized by rapid onset of
clinical symptoms, such as arrhythmias or various ECG changes
in severe cases- signs of chronic heart failure
-usually most patients recover quickly but in some of them years later,
chronic heart failure (due to dilated cardiomyopathy)
-giant cell myocarditis may have rapid progression- even cause death
Causes of myocarditis:
-most cases are of viral origin - particularly coxsackie viruses, influenza,
cytomegalovirus- cardiac involvement occurs several days to a few weeks after a
primary virus infection at another site
-noninfectious myocarditis- may be immune mediated, for example
myocarditis associated with rhematic fever, SLE, drug allergies, sarcoidosis
-idiopathic myocarditis- no infectious agent is found
typical example of idiopathic myocarditis is giant cell myocarditis and Fiedler
myocarditis (both are closely related)
-rarely of bacterial origin- often secondary in patients with bacteriemia
(staphylococcal)
morphology of myocarditis:
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-grossly- in acute phase of myocarditis the heart appears normal, or is
dilated, on cross section- the myocardium is of mottled appearance (patchy pale
foci and hemorrhagic lesions) - there are often mural thrombi in dilated
chambers, endocardium and valves are unaffected
-microscopically:
-in viral myocarditis- often multiple isolated myofiber necroses, interstitial
edema, inflammatory infiltration composed of lymphocytes, macrophages, rare
plasma cells
-in bacterial infections (pyogenes staphyloccoci)- microabscesses, patchy focal
suppurative reaction or more difuse infiltration in streptoccocal infections
-Fiedler myocarditis and giant cell myocarditis- both are characterized by focal
areas of myocardial necroses surrounded by granulomatous reaction often
including giant cells
both entities are probably the single disease of unknown, most likely immunologic
origin
after acute stage, there may be residual dilatation and hypertrophy of the heart
with multiple foci of interstitial fibrosis, less often no apparent changes, because
the inflammatory lesions may resolve completely
in severer cases- chronic heart failure due to dilated cardiomyopathy
CARDIOMYOPATHY
=the term implies a noniflammatory diffuse myocardial disease that is not related
to pressure or blood volume overload, not included rheumatic heart disease,
ischemic heart disease, congenital diseases etc.
primary CMP- is defined as myocardial disease of unknown etiology,
secondary CMP - refers to myocardial disorders of known causes
present use of the term “cardiomyopathy” includes cases with known cause, such
as cardiomyopathy due to amyloidosis and idiopathic with no apparent cause
cardiomyopathy can be divided into three clinicopathologic categories:
1) dilated ( congestive ) CMP
2) hypertrophic CMP
3) restrictive ( obliterative ) CMP
 1) DILATED CMP
-is characterized by marked gradual all four heart chamber dilatation with
an disorder in contractile function that lack any signs of myocarditis
-may occur at any age, its course is slow and progressive to CHF
- dilated CMP represents the end stage of a variety of myocardial
disorders- such as -the heart damaged by viral infection- end stage of viral injury
to myocardium
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CMP due to chronic alcohol abuse- alcohol has been shown to induce regression
changes within the myocardium of experimental animals- attributed to direct
toxicity of alcohol or to chronic thiamine deficiency ( similar to beri-beri)
pregnancy associated CMP-term applied to chronic heart failure that occurs in 3rd
trimester of pregnancy and first 6 months of puerperium-attributed to
nutritional defeciencies, hypertension or volume overload or may be vaguely
ascribed to clinically latent viral infection, but the basis of CMP is unclear
-the patient recover spontaneously, but is in greater risk in a subsequent
pregnancy
CMP due to cardiotoxic drugs, including adriamycin, daunorubicin, heavy metal,
such as cobalt and lithium)
idiopathic cases- vague histologic traces of previous myocarditis but not in all
cases morphology:
grossly- more distinctive changes than microscopically
-the heart has always an increased weight (up to 900g)
-significant dilatation of the chambers
severe functional disorder - poor cardiac contraction causes stasis of bloodintracardial mural thrombi (more often in atria)- valves and coronary arteries are
unaffected.
histologically:
-usually subtle and nonspecific changes
-25% patients have no significant alterations, the remainder show some
irregularities in the size and distribution of myofibers, atrophy and hypertrophy,
increase in interstitial tissue, sparse focal infiltration
- mild to moderate endocardial thickening is sometimes seen, especially in the
ventricles
clinical course:
-diagnosis is done by exclusion of other cause
-if established, the prognosis is very poor, because dilated CMP represents
a progressive chronic heart disease with poor contraction ability and markedly
reduced cardiac output
-death due to fatal arrhythmia or of systemic embolism from mural
thrombi, or of progressive CHF
 2) HYPERTROPHIC CMP ( asymmetric septal hypertrophy, or hypertrophic
obstructive CMP )
-is characterized by heavy hypercontractibility of the heart with poor
relaxation and filling and consequent rapid emtying
-the disease may be familial and is transmitted by autosomal dominant
inheritence ( in over half the patients)
pathogenesis:
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obscure- possible etiologies include:
-excessive myofibers response to catecholamines
-myocardial ischemia due to abnormal intramyocardial arteries
-primary collagen disorder with diffuse interstitial fibrosis resulting in
impairment of myofiber contraction and hypertrophy
morphology:- cardiac enlargment (great increase in weight)
disproportionate myocardial hypertrophy -most evident in the left ventricle and
interventricular septum
-on cross section- the left ventricular cavity may be compressed by hypertrophic
septum into the banana-like shape, bulging septum into the left ventricle cavity
-subaortic septal thickening may cause narrowing of the aortic outflow
histologically: disorganization of the hypertrophic myofibers that are arranged
haphazardly, and not in parallel bundles (more evident in the septum)
-the myofiber disarray is not always present and is most likely a secondary
phenomen attributable to abnormal wall and cellular stresses
-there is usually a diffuse delicate interstitial fibrosis
clinically: hypertrophic CMP occurs most often in young adults- there is an
increased risk of sudden death
-systematic disease presents with dyspnea, angina and CHF, but the
condition may be also asymptomatic
-the course of hypertrophic CMP is highly veriable
most patients with mild CMP improve or remain unchanged for years, only in
minority of patients the course is rapid
-major complications are atrial fibrillation with mural thrombi and embolism
outflow obstruction is seldom a major problem
 3) RESTRICTIVE ( OBLITERATIVE ) CMP
-is the least common type of CMP
is heterogenous group of diseases, such as cardiac amyloidosis, sarcoidosis,
endocardial fibroelastosis, endomyocardial fibrosis and Loeffler endocarditis
common to all: -reduced ventricular elasticity and reduced diastolic filling of the
heart chambers and thus reduced cardiac output
possible causes include
1) CARDIAC AMYLOIDOSIS- may occur as a part of systemic amyloidosis ( AA)
or may be due to isolated senile cardiac amyloidosis. Cardiac involvement may
induce arrhythmias or restrictive physiology.
2) ENDOMYOCARDIAL FIBROSIS
-is found typically in children and young adults in Africa
is characterized by ventricular subendocardial fibrosis extending from the apex
to outflow tract
there is variable amount of inflammatory infiltrate
complications include mural thrombi formation
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the cause is unknown- but theories include latent viral infection, malnutrition,
autoimmune reaction and even diet rich in serotonin ( bananas) resulting in
carcinoid-like effect on cardiac wall
3) LOEFFLER ENDOCARDITIS
-is characterized by endomyocardial fibrosis- large mural thrombi
frequently associated
with peripheral eosinophilia
eosinophilic infiltration in multiple organs, including heart
rapid fatal course
4) ENDOCARDIAL FIBROELASTOSIS:
-is uncommon heart disease charaterized by focal or diffuse cartilage-like
fibroelastic endocardial thickening
most often- only left heart is affected
the nature of the lesion is mysterious
-it has been related to past attacts of myocardial eosinophilia- maybe the lesion is
caused by released eosinophilic activated leukocytes
theories as to etiology: include hypoxia, chronic pressure overload, primary
myocardial enzymatic defect, etc.
clinical significance: depends on the extent of involvement - death due to emboli
or long term CHF
 PERICARDIAL DISEASES
-
almost always associated with disease in the heart, rarely pericardial
involvement may occur as a primary process
- most pericardial diseases are associated with...
Accumulation of fluid in pericardial sac may include
1.) pericardial effusion
2.) hemopericardium
3.) pericardial exudate
 1.) pericardial effusion-the normal pericardial sac contains 30 to 50 ml of
serous fluid
the term refers to non-inflammatory fluids in pericardial sac- distinguish against
exudate and hemopericardium
most effusions accumulate slowly-enlargement of the heart on X-ray
-pleural effusions may have various composition
serous-most common form
-serosa is smooth and glistening,
-fluid accumulates slowly and therefore it is well tolerated until very large
amount about 500 ml is formed
most common causes are congestive heart failure or in hypoproteinaemia
chylous- lymphatic obstruction
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idiopathic (cholesterol) in myxedema
 2.) hemopericardium- accumulation of blood in the pericardial sac without
inflammatory component
most common causes are
- rupture of myocardium in IM
- trauma
- rupture of the intrapericardial part of the aorta (Erdheim disease,
dissecting aneurysm)
- or due to hemorrhage from the cancer metastases
200-300 ml may cause death- because the blood escapes rapidly and produces
cardiac tamponade
 3.) pericardial exudate- accumulation of fluid due to inflammation
-usually secondary to disorders involving the heart (IM, trauma, tumors) or
due to systemic diseases (uremia, autoimmune diseases)
 acute pericarditis
serous- characterized by accumulation of serous fluidy exudate, in rheumatic
fever, uremia, tumors, SLE, primary viral origin
-the fluid resorbs completely without any residues
fibrinous or sero-fibrinous- the most common form, typically occurs in IM
-exudate may be completely resolved or be organized leaving typically delicate,
stringy adhesions= adhesive pericarditis
purulent- in fungal, bacterial or parasitic infections
-presents with prominent fever, rigors, fraction rub usually organizes and may
produce constrictive pericarditis
hemorrhagic-denotes an exudate admixed with blood
-most commonly associated with TBC or cancer
-may organize by collagen formation with secondary hyalinization and dystrophic
calcification
caseous pericarditis- due to TBC usually by direct extension from infected lymph
nodes
 chronic pericarditis
adhesive- fibrous plaques (“milk spots”) on the visceral pericardium or adhesions
between both two layers of the pericardium
-pericardial sac may be obliterated, the heart contracts with difficulties- results
in heart hypertrophy and dilatation
constrictive- uncommon chronic pericarditis, that is finally characterized by
encasement of the heart in a greatly thickened fibrotic pericardium
-the pericardial sac is obliterated and the fibrous pericardium constricts the
cardiac chambers
-particularly reduced is right atrial filling- elevation of blood pressure in large
veins -results in enlargment of the liver and ascites
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-marked thick, dense, fibrohyaline pericardial sac limiting the diastolic expansion
and restricting cardiac output
 TUMORS OF THE HEART AND PERICARDIUM
primary tumors are very rare
1) Cardiac myxoma - is a benign tumor of the endocardium- very rare, occurs
almost entirely in the atria
-is composed of small stellate cells embedded in an abundant myxoid extracellular
matrix
clinical features: -include fever, weight loss, anemia (unexplained)
-systemic embolism
-heart murmur
-possible cause of sudden unexpected death due to an acute prolapse of the tumor
mass into atrioventricular orifice which causes acute obstruction of circulation
2) Cardiac papillary fibroelastoma -very rare,
- tiny fine papillary protrusions on the valves
- they probably represent organized thrombi
3) Lipoma
circumscribed polypoid lesion, more often in LV, right atrium
4) Rhabdomyoma - the most common primary heart tumor in children (very rare)
grossly- gray-whitish ventricular mass
microscopically- composed of large polygonal eosinophilic cells of stellate shape“spider cells“
secondary tumors of the heart- more common (site of primary tumor- ca of lungs,
breast, malignant melanoma, lymphoma, leukemia)
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