Myocarditis

Question 1

dilated cardiomyopathy: clinical associated

Answer 1

-gradual development of cardiac failure
-4-chamber hypertrophy and dilatation
-20% -50% genetic, familial
-myocardial degeneration - defect in force generation,
force transmission and/or signaling
-common end pathway for a variety of myocardial insults
-suspected etiologies:
-alcohol or other toxicities
-previous myocarditis
-pregnancy associated with nutritional deficiency or immunologic

Question 2

primary abnormality

Answer 2

impairment of left ventricular function; end

stage ejection fraction <25% (systolic failure)

Question 3

dilated cardiomyopathy characteristics

Answer 3

• may occur at any stage age, usually 20-60
• clinical picture: slowly developing CHF
• may have precipitous decomposition, 50% die in 2 years
• need transplant

Question 4

etiologist for dilated cardiomyopathy

Answer 4

• alcohol, chemotherapeutic agents (doxorubicin/Adriamycin)

- Familial (25-35%): muscular dystrophy, cytoskeletal

Question 5

morphology of dilated cardiomyopathy

Answer 5

large,”globular” dilated hearts 2-3X normal size
-all chambers involved; wall thickness may be = normal
-mural thrombi common, especially near apex of
ventricles, atria
-functional mitral or tricuspid regurgitation
-left ventricle - patchy subendocardial scars; ?ischemic
-histology - most myofibers hypertrophied, stretched,
vacuolization
-interstitial and endocardial fibrosis; REPLACEMENT
fibrosis

Question 6

alcohol

Answer 6

-most common cause of dilated cardiomyopathy
-ETOH or its metabolites (acetaldehyde) has direct toxic
effect
-may be complicated by thiamin deficiency (beriberi heart
disease)

Question 7

toxic, metabolic, and other

Answer 7

alcohol
hyperthyroidism, hypothyroidism
peripartum state (pregnancy) 
adriamycin and other drugs
catecholamines

Question 8

pregnancy

Answer 8

• globally dilated heart
• ?due to hypertension, volume overload
• nutritional deficiency

Question 9

adriamycin and other drugs

Answer 9

-anthracycline chemotherapeutic agents doxorubicin,
daunorubicin - dose dependent
-also lithium, phenothiazines, cocaine
-attributed to lipid peroxidation of myofiber membranes
-myofiber swelling and vacuolization
-usually resolves on discontinuation of drug

Question 10

catecholamines

Answer 10

• pheochromocytoma - contraction band necrosis

- also dopamine, cocaine

Question 11

where else are contraction bands necrosis

Answer 11

seen with reperfusion injury
cocaine
catecholamines

Question 12

hypertrophic cardiomyopathy

Answer 12

-Idiopathic hypertrophic subaortic stenosis -IHSS
-Hypertrophic obstructive cardiomyopathy
-non-hypertensive heaving muscular hyper-contracting
heart
-100% genetic – defects in sarcomeric proteins
-Autosomal dominant with variable penetrance
-Missense mutations
-sometimes try surgical reduction of septum

Question 13

problems hypertrophic cardiomyopathy

Answer 13

atrial fibrillation, endocarditis, sudden death

Question 14

what causes the heart failure seen with hypertrophic cardiomyopathy

Answer 14

-heart failure due to decrease in chamber size, poor

compliance with decreased stroke volume (diastolic failure)

Question 15

what is seen with hypertrophic cardiomyopathy

Answer 15

-massive myocardial hypertrophy
-IHSS: disproportionate thickening of ventricular septum;
asymmetric hypertrophy (10% symmetric)
-jet lesions
-endocardial thickening/mural plaque formation of left
ventricular outflow tract; thickening of anterior mitral
leaflet 2° to contact with septum during systole

Question 16

histology of hypertrophic cardiomyopathy

Answer 16

-extensive myocyte hypertrophy; myocyte diameter >40 um
(normal 15 um)
-myofiber disarray; interstitial and replacement fibrosis

Question 17

glycogen storage disease

Answer 17

pompe’s disease

Question 18

pompe’s disease

Answer 18

1. acid alpha-glucosidase deficiency
   - accumulation of normal glycogen in cells
2. heart failure in infants
   - also juvenile, adult forms
3. restrictive heart disease
   - left ventricular hypertrophy with outflow obstruction
   - death from heart failure by age 1

Question 19

restrictive cardiomyopathy: clinical associations

Answer 19

-also a diastolic disorder
-diastolic relaxation and left ventricular filling impeded by
inability of myocardium to expand
-contractile (systolic) function of ventricle usually unaffected
-results from infiltrative diseases such as amyloidosis,
hemachromatosis, leukemia, or storage diseases
-also radiation fibrosis, constrictive pericarditis
-endocardial fibrosis

Question 20

restrictive cardiomyopathy causes

Answer 20

amyloidosis 
iron overload (hemachromatosis, hemosiderosis)

Question 21

restrictive cardiomyopathy: amyloidosis

Answer 21

-may be part of systemic amyloidosis or only affect
heart, particularly with senile isolated cardiac
amyloidosis
-two forms: ventricular (transthyretin) and atrial

Question 22

restrictive cardiomyopathy: iron overload

Answer 22

-more prominent in ventricles than atria
-interferes with metal-dependent enzyme systems
-accumulation of hemosiderin within cardiac myocytes (in
contrast to extracellular amyloid)

Question 23

variant forms of restrictive cardiomyopathy

Answer 23

endomyocardial fibrosis
Loeffler’s endomyocarditis
Endocardial fibroelastosis

Question 24

endomyocardial fibrosis

Answer 24

-children, young adults in Africa and tropical countries
-fibrosis or ventricular endocardium and
subendocardium
-extends from apex to inflow tract of rt/lt ventricles
-may involve mitral, tricuspid valves
-ventricular mural thrombi

Question 25

Loeffler's endomyocarditis

Answer 25

- similar to endocardial fibrosis but unrestricted to specific geographic area - EOSINOPHILS, leukocytosis - involvement of other organs - eosinophils appear to be functionally abnormal

Question 26

Endocardial fibroelastosis

Answer 26

-focal or diffuse cartilage-like fibroelastic thickening -first 2 yrs -often associated with congenital abnormalities (aortic valve obstruction) -remove thickened endocardium (“strip out”)

Question 27

myocarditis causes

Answer 27

viral

Question 28

who is invulnerable for myocarditis

Answer 28

infants immunosuppressed pregnant

Question 29

viruses common for myocarditis

Answer 29

``` coxsackie virus B ECHO polio influenza A/B *occurs days to weeks after primary viral infection ```

Question 30

morphology of myocarditis

Answer 30

-diffuse or patchy involvement; heart may be normal or dilated -interstitial mononuclear, predominantly lymphocytic inflammatory infiltrate; focal necrosis (not typical of ischemic necrosis): not all myocardial inflammation denotes myocarditis -organism-specific lesions, microabscesses

Question 31

variants of myocarditis

Answer 31

hypersensitivity myocarditis-> eosinophils | giant cell myocarditis-> associated with poorer prognosis

Question 32

non viral myocarditis

Answer 32

``` chagas lyme disease trichinosis AIDS Corynebacterium diptheriae ```

Question 33

myocarditis: chagas

Answer 33

-Trypanosoma cruzi; endemic in South America; increasing in North America; myocardial involvement found in 80%; 10% die during acute attack

Question 34

myocarditis: Corynebacterium diptheriae

Answer 34

(exotoxin); patchy myocytenecrosis with only sparse lymphocytic infiltrate

Question 35

myocarditis: AIDS

Answer 35

- Inflammation/myocyte damage without a clear etiologic agent - ?myocarditis caused directly by HIV or by opportunistic pathogen

Question 36

pericardial sac

Answer 36

-potential space, usually hold 50-60 ml serous fluid -lined on both sides with mesothelial layers of the serous pericardium -reflection of pericardium which covers the surface is call the visceral layer or epicardium -the layer forming the other side of the sac is called the parietal layer -heart and serous pericardium are encased several layers of the fibrous pericardium

Question 37

pericardial disease

Answer 37

-Almost always associated with disease in other portions of the heart or surrounding structures -Accumulations of fluid -normally 30-50 ml thin, clear, straw-colored, translucent fluid -pericardial effusions rarely exceed 500 ml -if slow, little clinical significance -if rapid, interfere with diastolic filling

Question 38

serous pericarditis

Answer 38

-non-infectious inflammation (RF, systemic lupus, scleroderma, tumors); viral infections

Question 39

most frequent type of pericarditis

Answer 39

Fibrinous and serofibrinous pericarditis

Question 40

what is seen with Fibrinous and serofibrinous pericarditis

Answer 40

1. myocardial infarction, Dressler’s syndrome (autoimmune conditions which appears several weeks after myocardial infarction) 2. uremia (“bread and butter” pericarditis) 3. chest irradiation

Question 41

most striking characteristic with fibrinous pericarditis

Answer 41

loud pericardial friction rub

Question 42

pericardial disease: purulent or suppurative

Answer 42

- invasion of organisms into pericardial space | - organization may lead to restrictive pericarditis

Question 43

pericardial disease: hemorrhagic

Answer 43

-exudate composed of blood mixed with a fibrinous or suppurative effusion -Tuberculosis, direct malignant neoplastic involvement of the pericardial space

Question 44

pericardial disease: chronic

Answer 44

-misnomer; healed or organized effusions with | fibrosis, adhesive (restrictive) pericarditis

Question 45

pericardial disease: rheumatic heart disease

Answer 45

-heart involved in 20-40% or cases; fibrinous pericarditis leading to fibrous adhesions

Question 46

pericardial disease: Hemopericardium

Answer 46

-due to rupture of heart wall secondary to myocardial infarction, traumatic perforation, or rupture of intrapericardial aorta -leads to cardiac tamponade -“electro-mechanical dissociation” -200-300 ml may cause death if accumulates rapidly

Question 47

neoplastic heart disease

Answer 47

myxoma

Question 48

myxoma

Answer 48

-most common primary tumor of the heart in adults; 90% are located in the atria (left to right 4:1) -almost always single -sessile or pedunculated masses -stellate or globular myxoma cells, endothelial cells, sm. muscle cells with abundant mucopolysaccharide ground substance; considered benign neoplasia -Ball-valve obstruction of atrial outflow, embolization, fever and malaise (?IL-6)