Module 6 CVS continued: Cardiomyopathies Flashcards
What tissue valve is involved in prosthetic valve endocarditis?
Pig valve - bioprosthetic
What metallic valve is involved in prosthetic valve endocarditis?
Metallic valve: mechanically ruptures RBCs as they pass through —- schistocytes (helmet cells) so increased unconjugated bilirubin (jaundice)
What bacteria is associated with prosthetic valve endocarditis?
S. epidermidis
(other causes: gram negative bacilli and fungi)
Fever + heart murmur
What does non bacterial thrombotic endocarditis (marantic) involve?
Sterile vegetations — mostly on mitral valve
What is the pathogenesis for marnatic endocarditis?
Incompletely understood --endothelial abnormalities --hypercoagulable states ---Adenocarcinomas (MUCIN) -- hypercoaguability NO BACTERIA NO INFLAMMATION OR FIBROSIS
What is libman-sacks endocarditis?
Sterile vegetations on the cardiac valves in patients with SLE
(vegetations are on both valve surfaces)
How do the vegetations appear for Marantic?
Small nodules along the line of closure (many or even one can be present)
For review: what are the 4 endocarditis that were talked about?
- Rheumatic heart disease: cross reacting Abs damage valve — susceptible to sub acute infective endocarditis — strep viridans (if dental work)
- Infective endocarditis: Native valve (acute = staph aureus and subacute = strep viridans) ; Prosthetic valve ( staph epidermis) ; IV druggies (staph. aureus)
- Non bacterial thrombic endocarditis (Marantic): imbalance of vichows triad (endothelial injury, stasis, hyper coag) = sterile vegetations
- Libman -Sacks: SLE= Ab/Ag complex (type 3HS) = damage valve—- sterile vegetation formation (thrombotic debris and fibrin)
What is myocarditis?
Generalized inflammation of myocardium associated with necrosis and degeneration of myocytes
(inflammation processes plays a primary role in development of myocardial injury)
What is the most common cause of viral myocarditis?
Coxsackie virus B (can be A)
- -this virus can also affect the pericardium and do pericarditis
- -usually asymptomatic
What is the pathogenesis for viral myocarditis?
Direct damage by virus and indirect damage via CD8+ mediated damage
Inflammation (infiltration of lymphocytes) — necrosis (patchy) of myocytes
What is the outcome of viral myocarditis?
Complete resolution
similar to lobar pneumonia and impetigo
What are complications of viral myocarditis?
MI
HEART FAILURE
DILATED CARDIOMYOPATHY
ARRYTHEMIAS
Review: what disease involve mitral valve stenosis?
Chronic Rheumatic heart disease (due to the fibrosis)
Review: What diseases involve mitral valve regurgitation?
Myxomatous Degeneration (mitral valve prolapse) Rheumatic Heart Disease Infective endocarditis Dilated cardiomyopathy Myocarditis
Review: What diseases involve aortic stenosis?
Rheumatic heart disease
Senile calcific aortic stenosis
Calcification of congenitally deformed valve (bicuspid)
Review: what diseases involve aortic regurgitation?
Rheumatic heart disease
Degenerative aortic dilation
Syphilitic aortitis
Marfan syndrome
What is cardiomyopathy?
Primary disease of the myocardium (The heart muscle itself) — intrinsic myocardial dysfunction
What are the 4 types of cardiomyopathy?
- Dilated
- Hypertrophic
- Restrictive
- Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC/ARVD)
Dilated cardiomyopathy is the most common type of cardiomyopathy, what are the common causes of dilated cardiomyopathy?
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
What is the presentation for dilated cardiomyopathy?
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
What are complications of dilated cardiomyopathy?
Arrhythmia + mural thrombus (Due to statsis)(because of mitral regurgitation) — embolize — lower limbs or brain (Stroke)
What investigations would you do for cardiomyopathy?
Echo: dilated heart chambers with low ejection fraction due to systolic dysfunction
Endomyocardial biopsy: hypertrophy of myocytes with interstitial fibrosis, without disarray
Hypertrophic or concentric hypertrophy cardiomyopathy is due to what?
Mutation in gene that codes for beta myosin heavy chain
also possible mutations in troponin T and alpha tropomyosin
Describe the hypertrophy in cardiomyopathy?
Haphazard/disarray of myocardial fibers aka myocytes
What are the presentations and findings on patients with hypertrophic cardiomyopathy?
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
What would you see on autopsy for hypertrophic cardiomyopathy?
Banana shaped left ventricle cavity
Asymmetric septal hypertrophy
Damage to the mitral valve
What are complications of hypertrophic cardiomyopathy/
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)
What is the etiology of restrictive cardiomyopathy?
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
What dysfunction is found in restrictive cardiomyopathy?
Primarily a Diastolic dysfunction (loss of ventricular compliance) and can be a systolic dysfunction (Not forceful)
Most interstitial fibrosis
What are some complications of restrictive cardiomyopathy?
Arrhythmias
Heart Failure
what is the etiology of arrhythmogenic right ventricular cardiomyopathy ?
Hereditary — genetic defect in desmosomes (adhesion proteins)
—plakoglobin: component of desmosomes that is mutated
What is the pathogenesis of arrhythmogenic right ventricular cardiomyopathy?
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
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)
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
What are the cardiac syndrome related to systolic (pumping) defect
- Dilated cardiomyopathy ( remember ventricles are HUGE so ventricles are overload with blood and cant pump it out) (S3)
- Congestive heart failure (remember symptoms are the same as dilated cardiomyopathy)
- Cardiogenic Shock
- Left Ventricular Aneurysm
What are the diastolic dysfunction (filling) defects?
- Pericardial cardiac tamponade
- Constrictive Pericarditis (like in TB)
- Restrictive cardiomyopathy (note can be a systole problem but mostly diastole)
- Hypertrophic cardiomyopathy (vetricles are super stiff and so blood is having a hard time coming in )
