Module 6 CVS continued: Cardiomyopathies

Question 1

What tissue valve is involved in prosthetic valve endocarditis?

Answer 1

Pig valve - bioprosthetic

Question 2

What metallic valve is involved in prosthetic valve endocarditis?

Answer 2

Metallic valve: mechanically ruptures RBCs as they pass through —- schistocytes (helmet cells) so increased unconjugated bilirubin (jaundice)

Question 3

What bacteria is associated with prosthetic valve endocarditis?

Answer 3

S. epidermidis
(other causes: gram negative bacilli and fungi)
Fever + heart murmur

Question 4

What does non bacterial thrombotic endocarditis (marantic) involve?

Answer 4

Sterile vegetations — mostly on mitral valve

Question 5

What is the pathogenesis for marnatic endocarditis?

Answer 5

Incompletely understood 
--endothelial abnormalities 
--hypercoagulable states 
---Adenocarcinomas (MUCIN) -- hypercoaguability 
NO BACTERIA 
NO INFLAMMATION OR FIBROSIS

Question 6

What is libman-sacks endocarditis?

Answer 6

Sterile vegetations on the cardiac valves in patients with SLE
(vegetations are on both valve surfaces)

Question 7

How do the vegetations appear for Marantic?

Answer 7

Small nodules along the line of closure (many or even one can be present)

Question 8

For review: what are the 4 endocarditis that were talked about?

Answer 8

1. Rheumatic heart disease: cross reacting Abs damage valve — susceptible to sub acute infective endocarditis — strep viridans (if dental work)
2. Infective endocarditis: Native valve (acute = staph aureus and subacute = strep viridans) ; Prosthetic valve ( staph epidermis) ; IV druggies (staph. aureus)
3. Non bacterial thrombic endocarditis (Marantic): imbalance of vichows triad (endothelial injury, stasis, hyper coag) = sterile vegetations
4. Libman -Sacks: SLE= Ab/Ag complex (type 3HS) = damage valve—- sterile vegetation formation (thrombotic debris and fibrin)

Question 9

What is myocarditis?

Answer 9

Generalized inflammation of myocardium associated with necrosis and degeneration of myocytes
(inflammation processes plays a primary role in development of myocardial injury)

Question 10

What is the most common cause of viral myocarditis?

Answer 10

Coxsackie virus B (can be A)

• -this virus can also affect the pericardium and do pericarditis
• -usually asymptomatic

Question 11

What is the pathogenesis for viral myocarditis?

Answer 11

Direct damage by virus and indirect damage via CD8+ mediated damage
Inflammation (infiltration of lymphocytes) — necrosis (patchy) of myocytes

Question 12

What is the outcome of viral myocarditis?

Answer 12

Complete resolution

similar to lobar pneumonia and impetigo

Question 13

What are complications of viral myocarditis?

Answer 13

MI
HEART FAILURE
DILATED CARDIOMYOPATHY
ARRYTHEMIAS

Question 14

Review: what disease involve mitral valve stenosis?

Answer 14

Chronic Rheumatic heart disease (due to the fibrosis)

Question 15

Review: What diseases involve mitral valve regurgitation?

Answer 15

Myxomatous Degeneration (mitral valve prolapse) 
Rheumatic Heart Disease 
Infective endocarditis 
Dilated cardiomyopathy 
Myocarditis

Question 16

Review: What diseases involve aortic stenosis?

Answer 16

Rheumatic heart disease
Senile calcific aortic stenosis
Calcification of congenitally deformed valve (bicuspid)

Question 17

Review: what diseases involve aortic regurgitation?

Answer 17

Rheumatic heart disease
Degenerative aortic dilation
Syphilitic aortitis
Marfan syndrome

Question 18

What is cardiomyopathy?

Answer 18

Primary disease of the myocardium (The heart muscle itself) — intrinsic myocardial dysfunction

Question 19

What are the 4 types of cardiomyopathy?

Answer 19

1. Dilated
2. Hypertrophic
3. Restrictive
4. Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC/ARVD)

Question 20

Dilated cardiomyopathy is the most common type of cardiomyopathy, what are the common causes of dilated cardiomyopathy?

Answer 20

Idiopathic but 5 pre disposing conditions:
Mutations in dystrophin and mitochondrial genes
Viral Myocarditis
Alcoholics due to thiamine deficiency B1 (Wet Beri Beri)
Peri-Partum cardiomyopathy ( before and after birth)
Hemochromatosis

Question 21

What is the presentation for dilated cardiomyopathy?

Answer 21

Combination of right and left heart failure because both ventricles are dilated (like CHF) (so symptoms are similar to that of CHF)

• —S3 sounds (gallop rhythm or Kentucky) — systolic contractile dysfunction (S3 is due to this volume overload of the ventricle)
• –Displaced apex beat due to dilation at 5th intercostal space mid-clavicular line – pushed to mid axillary line
• -remember this is systole is pumping of blood out of ventricles so if your ventricles are dilated then the blood cant get out
• -also hear crackles
• -low ejection fraction

Question 22

What are complications of dilated cardiomyopathy?

Answer 22

Arrhythmia + mural thrombus (Due to statsis)(because of mitral regurgitation) — embolize — lower limbs or brain (Stroke)

Question 23

What investigations would you do for cardiomyopathy?

Answer 23

Echo: dilated heart chambers with low ejection fraction due to systolic dysfunction
Endomyocardial biopsy: hypertrophy of myocytes with interstitial fibrosis, without disarray

Question 24

Hypertrophic or concentric hypertrophy cardiomyopathy is due to what?

Answer 24

Mutation in gene that codes for beta myosin heavy chain

also possible mutations in troponin T and alpha tropomyosin

Question 25

Describe the hypertrophy in cardiomyopathy?

Answer 25

Haphazard/disarray of myocardial fibers aka myocytes

Question 26

What are the presentations and findings on patients with hypertrophic cardiomyopathy?

Answer 26

Sudden cardiac death from arrhythmias (athlete that collapses and dies) - --diastolic dysfunction (remember that diastole is filling of the ventricles, so when your ventricles are so hypertrophic and become stiff you cant fill them) - --decreased left ventricular end diastolic volume and decreased stroke volume ---- normal ejection fraction - -IV septum: asymmetric hypertrophy --- makes contact with anterior leaflet of mitral valve during systole

Question 27

What would you see on autopsy for hypertrophic cardiomyopathy?

Answer 27

Banana shaped left ventricle cavity Asymmetric septal hypertrophy Damage to the mitral valve

Question 28

What are complications of hypertrophic cardiomyopathy/

Answer 28

Arrythymias Infective endocarditis of mitral valve due to dental work and s. viridens and LE gangrene Left heart failure Right heart failure mural thrombus due to stasis that can embolize and give stroke Infarcts of the septum (Small supply but increased demand---ischemia)

Question 29

What is the etiology of restrictive cardiomyopathy?

Answer 29

``` Endomyocardial fibrosis -- most common cause Hemochromatosis Amyloidosis Sarcoidosis Loefflers (eosinophilla) (Stem will be about a guy from the tropics that gets bit by Ascaris Lumbricioides gets Loeffler's sydrome and therefore gets restrictive cardiomyopathy) -- this parasite affects the mitral valve ```

Question 30

What dysfunction is found in restrictive cardiomyopathy?

Answer 30

Primarily a Diastolic dysfunction (loss of ventricular compliance) and can be a systolic dysfunction (Not forceful) Most interstitial fibrosis

Question 31

What are some complications of restrictive cardiomyopathy?

Answer 31

Arrhythmias | Heart Failure

Question 32

what is the etiology of arrhythmogenic right ventricular cardiomyopathy ?

Answer 32

Hereditary --- genetic defect in desmosomes (adhesion proteins) ---plakoglobin: component of desmosomes that is mutated

Question 33

What is the pathogenesis of arrhythmogenic right ventricular cardiomyopathy?

Answer 33

Fibrofatty replacement: of myocardium of RV free wall = thin and poor electrical transmission = right heart failure/arrhythmia = sudden cardiac death Transmural adipose infiltration of RV

Question 34

Sterile vegetations mostly contain fibrin, what are the line ups of these vegetations on the valves and their associated diseases? (remember its sterile so no inflammatory cells or bacteria)

Answer 34

Verrucae: Rheumatic Fever: in a straight line LSE (SLE): only one on both sides of the valve Infective endocarditis: vegetations in group Marantic (non bacterial thrombotic endocarditis): mostly on mitral valve, very few

Question 35

What are the cardiac syndrome related to systolic (pumping) defect

Answer 35

1. Dilated cardiomyopathy ( remember ventricles are HUGE so ventricles are overload with blood and cant pump it out) (S3) 2. Congestive heart failure (remember symptoms are the same as dilated cardiomyopathy) 3. Cardiogenic Shock 4. Left Ventricular Aneurysm

Question 36

What are the diastolic dysfunction (filling) defects?

Answer 36

1. Pericardial cardiac tamponade 2. Constrictive Pericarditis (like in TB) 3. Restrictive cardiomyopathy (note can be a systole problem but mostly diastole) 4. Hypertrophic cardiomyopathy (vetricles are super stiff and so blood is having a hard time coming in )