CPR 7.14 Pathology of Cardiomyopathies and Endocarditis

Question 1

Describe DCM

Answer 1

Ventricular chamber enlargement with impaired Systolic contractile function.

Question 2

Describe the gross and microscopic pathologic findings of DCM

Answer 2

2. Gross Pathology: Cardiomegaly, 4 chamber dilatation, Mural thrombi. p. 8
3. Microscopic Pathology: Non-specific. 75% of cases have myocytes hypertrophy and interstitial fibrosis. P. 9

Question 3

What are some common etiologies and contributing factors for DCM?

Answer 3

Idiopathic. Contributing factors include genetics, ETOH toxicity, post-viral myocarditis, and peripartum cardiomyopathy

Question 4

Define Hypertrophic CM

Answer 4

marked ventricular hypertrophy leading to reduced compliance and diastolic relaxation→ Impaired filling during Diastole

Question 5

Describe the gross and microscopic pathologic findings of HCM

Answer 5

1. Gross Pathology: Disproportionate thickening of ventricular septum vs. left ventricle free wall 3:1, Compressed banana shaped left ventricular cavity, Endocardial mural plaque (from contact b/t anterior mitral leaflet and septum). P.15-16
2. Microscopic Pathology: Massive myocytes hypertrophy, Haphazard myofiber disarray, Interstitial fibrosis. P. 17.

Question 6

What is the most common etiology for HCM?

Answer 6

Genetic (all). >50% autosomal dominant related to disorder of sarcomeric proteins.

Question 7

Define Restrictive CM

Answer 7

abnormally stiffened myocardium (due to fibrosis or infiltrative process) with impaired Disatolic relaxation

Question 8

Describe the gross and microscopic pathologic findings for primary idiopathic RCM

Answer 8

(2) Gross Pathology: Dilated atria. Normal cardiac size but firm myocardium.
(3) Microscopic Pathology: myocytes hypertrophy and patchy/diffuse interstitial fibrosis. P. 21

Question 9

Endocardial fibroelastosis, Endomyocardial fibrosis, Loeffler endocarditis, and myocardial deposition are all examples of what?

Answer 9

Secondary Restrictive Cardiomyopathy

Question 10

Describe the findings and gross pathology of endocardial fibroelastosis. (RCM)

Answer 10

(1) Endocardial fibroelastosis: focal/diffuse fibroelastic thickening of left ventricle.
i Gross pathology: Left ventricle>Right ventricle. Associated with CHD.

Question 11

Describe the findings and etiology of endomyocardial fibrosis. (RCM)

Answer 11

endocardial and subendocardial fibrosis with plaques.

i Etiology: Nutrition deficieicy or helminth induced inflammation. Africa and tropical areas. Most common form wordwide

Question 12

Describe the findings and prognosis associated with Loeffler endocarditis (RCM)

Answer 12

(3) Loeffler endocarditis: endocardial fibrosis with eosinophils with mural thrombus. Rapidly fatal.

Question 13

Describe how deposition of materials into the myocardium can result in amyloidosis as well as the gross and micro pathologic findings.

Answer 13

i Amyloid-insoluble proteins forming beta-pleated sheets.
• Gross: Waxy. P. 26
• Micro: pale pink between myocardial fibers. P. 27. Congo red stain causes amyloid to stain apple green with polarized light. P. 28

Question 14

Cardiogtoxic drugs, catecholamines, and hyper/hypothyroidism are all examples of what?

Answer 14

Secondary cardiomyopathy.

Question 15

Describe the most common viral and non-viral etiologies for myocarditis.

Answer 15

(a) Most often Viral. Coxsacki A&B virus or other enteroviruses.
(b) Non-viral: Trypanosoma cruzi (parasite), Borellia burgdorferi (bacteria).

Question 16

Describe the gross and microscopic pathologic findings associated with myocarditis.

Answer 16

2. Gross Pathology: Dilated CM, flabby ventricular myocardium, patchy diffuse hemorrhaging mottling, mural thrombi.
3. Microscopic Pathology: myocyte necrosis or degeneration, focal lesions, isolated myofiber necrosis with interstitial edema and mononuclear cell infiltrate with viral infections. P. 39
   (a) Giant cell p. 40
   (b) Chaga’s p. 43

Question 17

What area some non-infectious causes of myocarditis?

Answer 17

immune mediated (rheumatic fever, lupus, drug allergies/toxins), Idiopathic (sarcoidosis, giant cell myocarditis, Fiedler myocarditis).

Question 18

Define endocarditis and the general pathogenesis

Answer 18

1. Definition: microbial infection of the heart valaves or mural endocardim leading to formation of vegetations cmposed of thrombotic debris and organisms.
2. Pathogenesis: bactermia colonize in cardiac tissue.

Question 19

Describe the pathologic findings, at risk population, and common infectious microbe for acute IE

Answer 19

vegetations cause erosion of leaflet and abscess cavities. Common in IV drug users. Most often causd by Staph aureus (coag positive)

Question 20

Describe the pathologic findings and common microbe for IE

Answer 20

smaller vegetations that rately erode or cavitate. P. 56. Caused by streptococcus viridans. (30-40% of all IE).

Question 21

Infective endocarditis of prosthetic valves usually present with what pathologic finding?

Answer 21

ring abscess

Question 22

Patient’s who develop IE in a native valve were most likely infected with what organism?

Answer 22

Streptococcus viridans.

Question 23

A patient who develops IE in a prosthetic valve was most likely infected with what organism? Coagulase state?

Answer 23

S. epidermidis. Coagulase negative.

Could also be Staph. aureus (coagulase positive)

Question 24

IE in ulcerative pt with colitis or colorectal cancer was most likely caused by what organism?

Answer 24

Streptococcus bovis

Question 25

Where are the vegetations of non-infective endocarditis typically found?
What do they look like?

Answer 25

• Loosely adhered to valve leaflets along closure lines.

- Bland, faint pink microscopically p. 59

Question 26

What is a common form of Non-infectious endocarditis seen in SLE patients? Describe the hallmarks of this disease

Answer 26

Libman-Sacks endocarditis

-Mitral and Tricuspid disease disease with valve necrosis and degeneration. p. 62-63

Question 27

What is the most common etiology of rheumatic heart disease?

Answer 27

-Post GAS pharyngeal infection (could also be from skin infection)

Question 28

Describe the 2 most common cardiac lesions seen in the pancarditis of RHD

Answer 28

(1) Pericarditis “bread and butter” exudate. Myocarditis. And Endocarditis: MacCallum patch (thickening in left atrium); small warty vegetations along cusp closure . P. 66
(2) Aschoff nodules: swollen conglomeration of cells in interstitium of myocardium.. P. 68. Caterpillar cell p. 70.

Question 29

What is a common valvular complication of RHD?

Answer 29

Mitral stenosis

Question 30

What laboratory diagnostic tests can be used in prevention and confirmation of rheumatic fever/RHD?

Answer 30

: Pharyngeal culture for Group A Strep usually negative by te time illness begins. Serum titers for AB’s to DnaseB and streptlysin O will be welevated in patients with ARF