Download Cardiovascular system

Diseases of the Heart
Condition
Congestive Heart
Failure
Left-sided Heart
failure
Pathology
 Impaired cardiac function that
render the heart unable to
maintain an sufficient cardiac
output.
 Progressive deterioration of
myocardial contractile
function due to ischemic
injury, pressure or volume
overload or dilated
cardiomyopathy.
 Failures can result from an
inability of the heart chambers
to relax sufficiently during
diastole.
 Can occur with left
ventricular hypertrophy,
myocardial fibrosis,
deposition of amyloid or
constrictive pericarditis.
Causes:
 Ischemic heart disease
 Hypertension
 Aortic & mitral valve disease
 Myocardial disease
Clinical features
 Characterized by diminished
cardiac output or damming back
of blood in the venous system.
 Compensatory changes
ultimately constitute further
burdens on cardiac function.
Morphology

Compensatory changes:
 Hypertrophy makes myocytes
vulnerable to injury.
 Ventricular dilation (FrankStarling law).
 Blood volume expansion by salt
& water retention.
 Tachycardia.



Manifested by pulmonary

congestion & edema secondary
to impairment of lung vascular
outflow.
Reduced cardiac output results in
reduced renal perfusion.
CNS perfusion is reduced,
leading to hypoxic
encephalopathy.
1
Diseases of the Heart
Right-sided Heart
failure

Typically a consequence of
left-sided failure.
Caused by:
 Intrinsic disease of the lungs.
 Pulmonary vasculature
causing functional right
ventricular outflow
obstruction.
 Tricuspid or pulmonary
vulvar disease.
Ischemic heart
disease
Results of reduced renal perfusion:
 Further salt & water retention.
 Ischemic acute tubular necrosis.
 Impairment of waste excretion,
causing prerenal azotemia.
 Port, systemic & dependent

peripheral congestion & edema
& effusions.
 Congestive splenomegaly with
sinusoidal dilation, focal
hemorrhages, hemosiderin
deposits & fibrosis.
 Renal congestion, hypoxic injury
& acute tubular necrosis.
Hepatomegaly:
 Centrilobular congestion.
 Atrophy of central hepatocytes,
producing a nutmeg appearance.
 Severe hypoxia leads to
centrilobular necrosis.
 High right-sided pressure:
sinusoidal rupture causes central
hemorrhagic necrosis.
 Subsequent central fibrosis
creates cardiac sclerosis.
Caused by:
 Angina pectoris: paroxysmal
substernal or precordial pain or
 Reduced coronary blood flow;
often a combination of
discomfort.
coronary atherosclerosis with  Myocardial infarction is marked


Myocardium has variable
myocyte atrophy.
Perinuclear deposition of
lipofuscin, myocytolysis of
2
Diseases of the Heart

vasospasm, thrombosis, or
both.
Increased myocardial demand
exceeding vascular supply.


Myocardial
infarction
Types of MI:
 Transmural infarct: infarction
of full thickness of ventricular
wall, caused by severe
coronary atherosclerosis
worsened by plaque
disruption & superimposed
occlusive thrombosis.
 Subendocardial infarct:
by death of cardiac muscle.
Chronic ischemic heart disease is 
seen typically in elderly patients;
may result from postinfarction

cardiac decompensation or slow
ischemic myocyte degeneration.
Sudden cardiac death:
unexpected death within 1 hour
of onset of symptoms.
Causes of sudden cardiac death:
 Aortic valvular stenosis.
 Hereditary or acquired
conduction system
abnormalities.
 Electrolyte derangements.
 Mitral valve prolapse.
 Dilated or hypertropic
cardiomyopathy.
 Ultimate mechanism of death is
a fatal arrhythmia.
 Chest pain
 Nausea
 Diaphoresis
 Dyspnea
 ECG changes
 Serum elevation of myocardial
enzymes, e.g. creatine kinaseMB isozyme.
 25% of patients experience
single cells or clusters.
Diffuse perivascular &
interstitial fibrosis.
Patchy to confluent replacement
fibrosis.
Gross:
 6-12 hours: lesions is usually
inapparent.
 18-24 hours: infarcted tissue is
readily apparent – pale to
cyanotic.
 First week: lesions becomes
progressively more sharply
defined, yellow, & softened.
3
Diseases of the Heart
limited to inner one third to
one half of ventricular wall.

Typical sites of plaques:
 Proximal 2cm of the left
anterior descending & left
circumflex coronary arteries.
 Proximal & distal thirds of the
right coronary artery.
Pathogenesis:
 Nearly all transmural MIs
affect left ventricle; 15%
simultaneously involve right
ventricle; isolated right
ventricle infarction occurs in
1-3% of cases.
 Initial event in transmural MI:
erosion, ulceration, fissuring,
rupture or hemorrhagic
expansion.
 Thrombosis follows acute
plaque change.
 Time interval between onset
of complete myocardial
ischemia & initiation of
irreversible injury: 20-40
minutes.
 Thrombi may lyse
spontaneously, reestablishing
sudden death after infarction,
secondary to a fatal arrhythmia.
80-90% of survivors develop
complications.


Complications:
 Arrhythmias
 Congestive heart failure
 Cardiogenic shock
 Ventricular rupture within first
10 days – rupture of free wall
causing pericardial hemorrhage
& tamponade & rupture of
septum producing a left-to-right
shunt with right-sided heart
volume overload.
 Papillary muscle infarction with
or without rupture.
 Fibrinous-to-hemorrhagic
pericarditis, common 2-3 days
postinfarction.
 Mural thrombosis with risk of
peripheral embolization.
7-10 days: a circumferential rim
of hyperemic granulation tissue
appears & progressively
expands.
6 weeks: white fibrous scar is
established.
Histology:
 1 hour: intercellular edema, &
myocytes at edge of infarct
become wavy & buckled.
 12-72 hours: neutrophilic
infiltration into necrotic tissue,
with myocyte coagulative
necrosis; dead myocytes
become hypereosinophilic with
loss of nuclei.
 7-10 days: granulation tissue
progressively replaces necrotic
tissue, generating a dense
fibrous scar.
4
Diseases of the Heart
flow.
Causes of Subendocardial
infarcts:
 Diffuse coronary
atherosclerosis.
 Global borderline perfusion
made critical by increased
demand, vasospasm, or
hypotension.
 Disrupted plaque with
overlying thrombus.
Hypertensive Heart Disease
Systemic (left Myocyte hypertrophic
sided) hypertensive
enlargement as a response to
heart disease
increased work.
 Thickened myocardium
reduces left ventricle
compliance, impairing
diastolic filling while
increasing oxygen demand.
 Individual myocyte
hypertrophy increases
distance for oxygen &
nutrient diffusion from
adjacent capillaries.
Pulmonary (right Right ventricle hypertrophy is
sided) heart disease
secondary to pulmonary
(Cor Pulmonale)
hypertension caused by
disorders affecting lung


Increases risk of sudden cardiac
death.
Remainder die of renal disease,
stroke, or unrelated causes.






Thickened left ventricle wall
with increased heart weight
(>2cm wall thickness, heart
weight > 500gm).
Myocytes & nuclei are
enlarged.
Diffuse interstitial fibrosis &
focal myocyte atrophy &
degeneration may develop, with
left ventricle chamber dilation
& wall thinning.
Right ventricle hypertrophy, to
1cm or more in thickness;
dilation, or both.
Right ventricle dilation may
5
Diseases of the Heart



Valvular Heart Disease
Degenerative

calcific aortic valve
stenosis

Mitral Annular
Calcification


structure or function.
Acute cor pulmonale: right
ventricle dilation after
massive pulmonary
embolization.
Chronic cor pulmonale: result
of chronic right ventricle
pressure overload.
Vasoconstriction in
pulmonary vasculature
incident to hypoxemia &
acidosis exacerbates
pulmonary hypertension.


Age-related lesions clinically
important in patients in their
70s & 80s.
Remainder are congenital
bicuspid valves.



Degenerataive,
noninflammatory calcific
deposits within mitral
annulus, usually in the
elderly.
Regurgitation may occur
owing to inadequate sytolic
contraction of the mitral valve

Angina
Syncope
Congestive heart failure


lead to tricuspid regurgitation.
Pulmonary arteriolar wall
thickening.
Left side of heart is normal.
Heaped-up subendothelial rigid
calcific masses within sinuses
of Valsalva cause thickening &
immobility of the valve cusps
with narrowing of orifice.
There is usually concentric left
ventricle hypertrophy from
chronic pressure overload.

6
Diseases of the Heart


Mitral valve
prolapse


Rheumatic Fever &
Rheumatic heart
disease


ring.
Leaflets may be unable to
open over bulky deposits,
causing stenosis.
Nodular calcific deposits may
cause arrhythmias by
impinging on the conduction
pathways.
One or both mitral valve
leaflets are enlarged,
myxomatours & floppy, &
they balloon back into left
atrium during systole, causing
midsystolic click & mitral
valve insufficiency.
Common in Marfan
syndrome.
An acute, recurrent
inflammatory disease that
occurs 1-5 weeks after group
A streptococcal infection.
Occurs mainly in children

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



Generally asymptomatic.
Discovered only as a midsystolic
click on auscultation.
Atypical chest pain.
Dyspnea
Fatigue
Psychiatric manifestations:
depression, anxiety.
Gross:
 Interchordal ballooning (>4cm)
of mitral valve leaflets.
 Elongated, attenuated, or
ruptured chordae tendineae.
 Fibrous thickening of valve
leaflets.
 Thickened left ventricular
endocardium.
 Atrial thrombosis
 Calcification of mitral annulus.
Patients have increased risk of:
 Infective endocarditis
 Slow, progressive mitral valvular
Histology:
insufficiency that may produce
 Thinning & degeneration of
congestive heart failure.
fibrosa layer.
 Atrial & ventricular arrhythmias

Myoxomatous thickening of
 Sudden death
spongiosa.
Changes secondary to tight mitral
Histology:
stenois:
 Aschoff bodies are foci of
fibrinoid necrosis surrounded by
 Left atrial hypertrophy &
enlargement, occasionally with
lymphocytes, macrophages &
mural thrombi.
slowly replaced by fibrous scar.
7
Diseases of the Heart

between 5-15 years of age.
Secondary to host
antistreptococcal antibodies
that are cross reactive to
cardiac antigens.
Chronic rheumatic heart disease
is more likely to occur:
 when first attack is in early
childhood.
 when first bout of rheumatic
fever is severe.
 with recurrent attacks.
Vegetative Endocarditis
Infective
 Colonization of heart valves
Endocarditis
with microbiologic organisms
leads to formation of friable,
infected vegetations & valve
injury.



Chronic congestive changes in
the lungs.
Right ventricle hypertrophy
Congestive heart failure
Complications:
 Increased risk of developing
infective endocarditis.
 Atrial fibrillation secondary to
atrial dilation.
Diagnosis requires presence of 2 of
5 major Jones criteria:
 Erythema marginatum: macular
skin lesions with erythematous
rims & central clearing.
 Sydenham chorea: neurologic
disorder with rapid, involuntary,
purposeless movements.
 Carditis
 Subcutaneous nodules
 MIgratory large joint
polyarthritis: 90% of adults, less
common in children.
Acute infective endocarditis:
 Rapidly developing fever with
rigors, malaise, & weakness.
 Larger vegetations often cause
embolic complications.


Inflammatory valvulitis induces
formation of beady fibrinous
vegetations; aschoff bodies may
be present in inflamed valves.
Subendocardial collections of
Aschoff nodules in left atrium
usually induced thickenings
called MacCallum plaques.
Chronic valve shows:
 Fibrous thickening of leaflets.
 Bridging fibrosis across
commissures.
 Thickened, fused, & shortened
mitral valve chordae.
 Calcification deep in fibrous
leaflets.


Friable, 0.5-2.0cm, microbeladen vegetations are found on
one or more valves.
Acute infective endocarditis is
associated with bulky
8
Diseases of the Heart
Acute infective endocarditis:
 Caused by highly virulent
organisms, e.g. S. aureus.
 Seeding a previously normal
valve & producing a
necrotizing, ulcerative, &
invasive infection.
Subacute infective endocarditis:
 Caused by an organism of
moderate to low virulence,
e.g. Streptococcus viridans.
 Seeding an abnormal or
previously injured valve,
causing less valvular
destruction than acute
infective endocarditis.
Predisposing factors:
 Cardiac congenital
abnormalities: tight shunts or
stenoses with jet stream.
 Mitral valve prolapse
 Degenerative calcific stenosis
 BIcuspid aortic valve
 Prosthetic valves
 Indwelling catheters
 Neutropenia
 Immunosuppressed states
 Intravenous drug abuse


Splenomegaly is frequent.
Even with treatment, death
occurs in days to weeks in 5060% of patients.
Subacute infective endocarditis:
 Insidious onset with malaise,
low-grade fever, weight loss &
flulike syndrome.
 Embolic complications are less
frequent due to smaller
vegetations.
 Tends to have a protracted
course & is less fatal than acute
form.




vegetations that cause erosions
or perforations of leaflets,
invading adjacent myocardium
to produce abscesses.
Subacute infective endocarditis
has smaller vegetations that
rarely erode or penetrate
leaflets.
Nonvalvular vegetations are
found on downstream margin of
a jet lesion.
Ring abscess is present with
prosthetic valves.
With intravenous drug abuse,
vegetations are often acute & or
on right-sided valves.
Clinical consequences:
 Direct injury to valves.
 Emboli to spleen, kidneys, heart
& brain with infarction or
metastatic infection.
 Renal injury: embolic infarction
or glomerulonephritis.
Diagnosis is confirmed by blood
cultures.
9
Diseases of the Heart
Nonbacterial
Thrombotic
Endocarditis
Occurs in settings of disseminated
intravascular coagulation or other
hypercoagulable state:
 Cancer: visceral
adenocarcinomas
 Renal failure
 Chronic sepsis
Endocarditis
 Valvulitis may appear in
associated with SLE
systemic lupus erythematous
& antiphospholipid syndrome.
 Mitral & tricuspid valves are
most often affected with
fibrinoid necrosis, mucoid
degeneration & subsequent
development of small,
fibrinous, sterile vegetations
on either side of valve
leaflets.
Carcinoid heart
 Elaboration of
disease
argentaffinomas of bioactive
products – serotonin,
kallikrein, histamine &
prostaglandins.
 Predominantly right-sided
heart lesions.

Small (1-5mm), sterile, bland
fibrin & platelet thrombi loosely
adherent to valve leaflets.




Plaquelike intimal thickenings
of endocardium of tricuspid
valve, right ventricular flow
tract & pulmonic valve.
Left side of heart is usually
unaffected.
Use of fenfluramine &
phentermine, appetite
suppressants used to treat
obesity associated with similar
left-sided valve lesions.
10
Diseases of the Heart
Complications of
artificial valves
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Cardiomyopathy
Dilated
cardiomyopathy


Hypertrophic
cardiomyopathy

Paravalvular leak: separation
of sewing ring from valve
annulus.
Thrombosis,
thromboembolism, or both.
Infective endocarditis.
Structural deterioration.
Occlusion as a result of tissue
overgrowth.
Hemolysis from mechanical
trauma to erythrocytes.
Gradual four-chamber
hypertrophy & dilation.
May occur at any age as slow,
progressive congestive heart
failure.
Causes:
 Genetic defect
 Alcohol toxicity
 Peripartum cardiomyopathy
 Postviral myocarditis
 Heavy, muscular,
hypercontractile, poorly
compliant heart with poor
diastolic relaxation.
 Autosomal dominant
inheritance: mutations of gene
for myosin heavy chain &
Arrhythmogenic right ventricular
cardiomyopathy:
 Heart failure & various rhythm
disturbances.
 Ventricular tachycardia &
sudden death.
 Death occurs secondary to
progressive congestive heart
failure, embolism of mural
thrombi, or fatal arrhythmias.

Clinical symptoms:
 Dyspnea
 Angina
 Near-syncope
 Congestive heart failure





Cardiomegaly (up to 900gm) &
flabby heart.
Poor contractile function &
stasis lead to mural thrombi.
Milde to moderate focal
endocardial thickening in
ventricles.
Right ventricular wall is
severely thinned, with excessive
fatty infiltration, loss of
myocytes & interstitial fibrosis.
Cardiomegaly, owing to
hypertrophy, often with atrial
dilation.
Disproportionate thickening of
the septum versus left ventricle
free wall (asymmetrical septal
hypertrophy)
11
Diseases of the Heart

Restrictive
cardiomyopathy




other contractile proteins.
Increased risk of sudden
death.
Restriction of ventricular
filling & reduced cardiac
output.
Interstitial myocardial fibrosis
is usually present.
Endomyocardial fibrosis:
found typically in young
children & adults in Africa.
Endocardial fibroelastosis:
common in patients younger
than 2 years old, one-third
with congenital abnormalities.
Complications:
 Atrial fibrillation with mural
thrombus
 Embolization
 Infective endocarditis
 Congestive heart failure
 Sudden death

Left ventricle cavity
compressed into a banana-like
configuration.
 Septum shows helter-skelter
myocyte disarray, accompanied
by myofilament disorganization
within muscle cells.
 Patchy replacement fibrosis as a
result of focal ischemic injury &
abnormal thick-walled arteries
of unknown origin.
Endomyocardial fibrosis:
 Ventricular subendocardial
fibrosis.
 Mural thrombus formation.
Loeffler endocarditis:
 Endomyocardial fibrosis with
large mural thrombi.
 Peripheral eosinophilia.
 Eosinophilic infiltration of
multiple organs, including heart
(rapid fatal course).
Endocardial fibroelastosis:
 Focal-to-diffuse, cartilage-like
fibroelastic thickening of
endocardium.
 Affects left ventricle more.
12
Diseases of the Heart
Myocarditis
Infections:
 Viruses: coxsackievirus,
ECHO, influenza, HIV,
CMV.
 Chlamydia: C. psittaci
 Rickettsia
 Bacteria: Corynebacterium,
meningococcus, Borrelia.
 Fungi: Candida
 Protozoa: Trypanosoma cruzi,
toxoplasmosis
 Helminths: trichinosis
Immune-mediated reactions:
 Postviral
 Poststreptococcal (rheumatic
fever)
 Systemic lupus erythematous
 Drug hypersensitivity:
methyldopa, sulfonamides
 Transplant rejection
Unknown:
 Sarcoidosis
 Giant cell myocarditis





Asymptomatic
Abrupt onset of arrhythmia
Congestive heart failure
Sudden death
Most patients recover quickly
without sequelae.
Gross:
 Flabby ventricular myocardium
 Four-chamber dilation
 Patchy, diffuse hemorrhagic
mottling.
 Mural thrombi arise in dilated
chambers.
Histology:
 Myocardial inflammatory
infiltrate with associated
myocyte necrosis or
degeneration.
 Lesions are typically focal.
 Myocarditis associated with
viral infections: isolated
myofiber necrosis with
interstitial edema &
mononuclear cell infiltrate.
 Chagas disease: trypanosomes
parasitize myocytes & produce
acute & chronic inflammation,
including eosinophils.
 Idiopathic giant cell
myocarditis: focal myocyte
necrosis associated with
granulomatous inflammation,
including multinucleated giant
cells.

13
Diseases of the Heart
Other myocardium
diseases

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
Pericardial Disease
Pericardial effusion 


Hemopericardium


Doxorubicin & Daunorubicin
induce a dose-dependent
cardiotoxicity due to lipid
peroxidation of myofiber
membranes.
Iron overload with
hemosiderin deposits in
myofibers occur in hereditary
hemochromatosis &
hemosiderosis from multiple
blood transfusions.
Amyloidosis: patchy &
perivascular hyaline deposits.
Catecholamines induce
tachycardia & vasomotor
constriction resulting in
diffuse patchy ischemic
necrosis.



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

Serous form is most common.
Fluid accumulates slowly till
a large volume compromises
diastolic filling.
Most common causes are
congestive heart failure &
hypoproteinemia.
Accumulation of pure, clotted
blood in pericardium without
an inflammatory component.
200-300ml may cause






Myofiber swelling
Fatty change
Individual cell lysis
Mitochondrial abnormalities
Smooth endoplasmic reticulum
swelling & fragmentation
Myofibril lysis
Delicate interstitial fibrosis &
focal replacement scarring
occur with time.
14
Diseases of the Heart
tamponade.
Acute Pericarditis
Causes:
 Traumatic perforation.
 Myocardial rupture after a
transmural MI.
 Rupture of intrapericardial
aorta.
 Hemorrhage from an abscess
or tumor metastasis.
Serous:
 Consists of 50-200ml of
slowly accumulating exudate.
 Produced by rheumatic fever,
SLE, tumors, uremia &
primary viral infection.
 Scant epicardial & pericardial
acute & chronic inflammatory
infiltrate.


Fibrinous:
 Most common clinical form.
 Seen with MI
 Associated with a pericardial
rub.
 Exudate may be completely
resolved or organized leaving
delicate, stringy adhesions.
15
Diseases of the Heart
Purulent:
 Bacterial, fungal or parasitic
infection which has reached
pericardium by direct seeding,
hematogenous or lymphatic
spread.
 Common causes: grampositive staphylococci,
streptococci & pneumococci.
 400-500ml of thin-to-creamy
pus with erythematous,
granular serosal surfaces.
 Presents with fever, rigors & a
friction rub.
Hemorrhagic:
 Exduate of blood mixed with
fibrinous-to-suppurative
effusion.
 Follows cardiac surgery.
 Associated with tuberculosis
or malignancy.
 Usually organizes without
calcification.
Chronic Pericarditis
Caseous: due to tuberculosis or
mycotic infection.
Healing of acute lesions lead to:
 Resolution
 Pericardial fibrosis ranging


16
Diseases of the Heart
from a thick, nonadherent
epicardial plaque to thin,
delicate adhesions.
Adhesive mediastinopericarditis:
 Pericardial sac is obliterated.
 Parietal layer is tethered to
mediastinal tissue.
 Heart contract against
surrounding attached
structures, with subsequent
hypertrophy & dilation.
Rheumatoid heart
disease
Constrictive pericarditis:
 Thick, dense fibrous
obliteration.
 Calcification of pericardial
sac.
 Limit diastolic expansion &
restricting cardiac output.
 Common cause: tuberculosis.
 Rheumatoid arthritis in 2040% of severe chronic cases.
 Pericarditis, marked by a
mixture of fibrin & necrotic
debris derived from
pericardial rheumatoid
granulomas.
 Progress to form dense,
fibrous, & restrictive


17
Diseases of the Heart
adhesions.
Tumors
Myxomas



Lipomas
Papillary
fibroelastomas
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
Rhabdomyomas

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
Most common primary
cardiac tumors in adults.
90% arise in atria in region of
fossa ovale.
Cause symptoms by physical
obstruction or trauma to
atrioventricular valves.
Probably hamartomas.
Circumscribed but poorly
encapsulated large polypoid
accumulations of adipose
tissue.
Probably hamartomas.
Commonly found on rightsided valves in children &
left-sided valves in adults.
Composed of 2-55mm
hairlike projections.
Probably derived from
organized thrombi.
Most common primary heart
tumor in children.
May cause valvular or
outflow tract obstruction.
Probably hamartomas.



Composed of stellate or
globular multipotential
mesenchymal myxoma cells.
Admixed with endothelia,
smooth muscle & inflammatory
cells.




Filaments have a core of
myxoid connective tissue with
smooth muscle cells &
fibroblasts, covered by
endothelium.


Composed of large, rounded or
polygonal cells rich in glycogen
& containing myofibrils.
Cytoplasmic strands radiating
from central nucleus to plasma
membrane create spider cells.

18
Diseases of the Heart
Congenital heart disease:
 Most critical juncture is embryologic cardiac development in gestational weeks 3 through 8.
 Complications: failure to thrive, retarded development, cyanosis, increased risk of chronic illness & of infective endocarditis.
Shunts
Secondary findings:
 Abnormal communication

between heart chambers,
 Clubbing of fingers & toes
vessels, or between chambers  Hypertrophic osteoarthropathy
& vessels.
 Polycythemia
Left-to-Right Shunts: Late Cyanosis
Atrial septal defect  Abnormal opening in the
 Usually asymptomatic until

atrial septum that allows free
adulthood.
communication of blood.
 Right-sided heart failure.
 Most common congenital
 Right-sided hypertrophy.
cardiac anomaly in adults.
 Surgical correction early in life
 Primum type: 5%; common in
prevents pulmonary vascular
Down syndrome.
changes & paradoxic embolism.
 Secundum type: 90%, occurs
at foramen ovale.
 Sinus venosus type: 5%;
occurs high in septum & near
superior vena cava entrance.
Ventricular septal
 Abnormal opening in
 Fulminant congestive heart

defect
ventricular septum that allows
failure.
free communication between
 Late cyanosis.
left & right ventricles.
 Asymptomatic holosystolic
 Most common congenital
murmurs.
cardiac anomaly.
 Spontaneous closure.
 Associated with other
 Increased risk of infective
structural anomalies such as
endocarditis.
tetralogy of Fallot; 30% are
 Surgical correction needed
isolated.
before right-sided heart overload
19
Diseases of the Heart
Patent ductus
arteriosus

In fetus, ductus arteriosus
permits blood flow between
aorta & pulmonary artery.
 85-90% isolated defects.
 Associated left ventricle
hypertrophy & pulmonary
artery dilation.
Right-to-Left Shunts: Early Cyanosis
Tetralogy of Fallot
 Due to embryologic
anterosuperior displacement
of infundibular septum.
Four cardinal features:
 Ventricular septal defect
 Dextroposed aorta overriding
the ventricular septal defect
 Pulmonary stenosis with right
ventricle outflow obstruction
 Right ventricle hypertrophy
Transposition of
 The aorta arises from right
great arteries
ventricle & pulmonary artery
from the left.
 Common in children of
diabetic mothers.
Truncus arteriosus
 Associated with numerous
cardiac defects.
 A developmental failure of
the aorta & pulmonary artery
to separate.



& pulmonary vascular disease
develop.
Initially asymptomatic with
prominent heart murmur.
Pulmonary hypertension with
right ventricle hyperthropy.
Early closure with prostaglandin
or surgery.


Cyanosis is present from birth or
soon after.


Prognosis depends on severity of
tissue hypoxia & ability of right
ventricle to maintain aortic flow.
Untreated, most children die
within a few months.




20
Diseases of the Heart

Results in an infundibular
ventricular septal defect with
a single vessel receiving
blood from both right & left
ventricles.
Obstructive Congenital Anomalies
Coarctation of aorta  Constriction of aorta with
cardiomegaly.
Preductal coarctation:
 Manifests early in life & may
be rapidly fatal.
 Lower body cyanosis
 Involves a 1-5cm segment of
aortic root.
 Associated with fetal right
ventricle hypertrophy & early
right-sided heart failure.

Untreated, mean life span is 40
years.

Death secondary to:
 Congestive heart failure.
 Aortic dissection proximal to
coarctation.
 Intracranial hemorrhage.
 Infective endocarditis at site of
narrowing.
Postductal coarctation:
 Generally asymptomatic
unless severe.
 Leads to upper extremity
hypertension.
 Low flow & hypotension in
lower extremities.
 Arterial insufficiency:
claudication & cold
sensitivity.
 Collateral flow: internal
21
Diseases of the Heart
Pulmonary valve
stenosis


Aortic valve
stenosis & atresia

mammary & axillary artery
dilation.
Occurs in isolation or in
association with other
anomalies.
Complete pulmonic atresia:
hypoplastic right ventricle &
an atrial septal defect with
blood entering lungs via a
patent ductus arteriosus.
Congenital complete aortic
atresia is rare & incompatible
with neonatal survival.

Mild stenosis is generally
asymptomatic.




Infective endocarditis.
Left ventricle hypertrophy.
Poststenotic dilation of aortic
root.
Sudden death (rare).


22