Cardiac Path Flashcards
What is a cardiomyopathy
heart disease resulting from a primary abn. in the myocardium
long standing pressure changes -> hypertrophy
long standing volume changes -> dilated
What are the 3 types of cardiomyopathies?
dilated, hypertrophic, restrictive
Describe dilated CM
progressive chamber dilated, results in reduced EF
causes: ABCD PIG
Most common type of CM?
dilated CM
Two classes of drugs that can cause dilated CM?
Adriamycin (Doxorubicin)
Cytoxin
(both CA drugs)
What would a dilated CM heart look like pathologically?
heavy heart which is large and flappy with dilation of all chambers
gross/microscopic findings of dilated CM?
thin walls partially replaced w/ fibrous tissue
How is genetic idiopathic dilated cardiomyopathy transmitted?
autosomal dominant, but also autosomal and sex linked recessive
What is the most common identifiable cause of secondary dilated CM in the U.S? other causes?
alcohol
cocaine use, cobalt exposure, viral myocarditis, pregnancy, high catecholamines (pheochromocytoma)
Describe hypertrophic CM
extensive hypertrophy of LV
HCM is also known as…
IHSS (idiopathic hypertrophic subaortic stenosis)
heart enlarged >1200g
What can you see grossly in HCM?
asymmetrical thickening of the ventricular septum
“banana septum”
+/- endocardial thickening with mural plaque formation of outflow track
Describe restrictive CM
Decreased in ventricular compliance so decreased V filling during diastole with normal systolic func.
cannot expand appropriately to receive blood
causes of restrictive CM?
idiopathic, amyloid, sarcoidosis, metastatic tumor (radiation)
Gross/microscopic findings of restrictive CM?
chambers not dilated, myocardium firm.
Histologically: patchy/diffuse interstitial fibrosis
CM dx?
ECG/echo
definitive: endomyocardial biopsy
What is acute rheumatic fever?
A systemic, immunologically mediated disease related to a streptococcal infection
our immune cells can’t tell the dif. btwn our cells and bacteria
What causes RF?
a serotype called a rheumatic stain by group A hemolytic strep (strep pyogenes)
usually followed by strep throat infection- not treated appropriately/noncompliance
rheumatic heart diseases causes…
fibrinous pancarditits- covering all 3 layers of the heart
- bread and butter pericarditis
- Myocarditis with histologic aschoff bodies
- Endocarditis- valvular problems
What is the number one cause of death in acute RF?
arrhythmias
How does our immune rxn cause disease in RF?
immune rxn damages connective tissue of heart and several other organs
abs against strep antigens may cross react with similar antigens in the heart
Who is most susceptible to ARF?
children 9-11 yrs
Why is RF no longer common?
better abx
less crowed conditions
still worldwide leading cause of heart disease in ppl 5-25
What is rheumatic heart disease?
major comp of ARF
also involves joints, subcutaneous CT of skin, blood vessel and occasionally brain
Pathology of RHD?
nonbacterial sterile, inflammatory lesions and granulomas throughout connective tissue of body
What is characteristic about the heart valve ulcerations in RHD with time?
sterile vegetations (no bacteria)
located along the lines of closure of the valve leaflets
What is characteristic of the vegetations of RHD?
no bacteria within the vegetations
ongoing inflammation inside of the valves leads to destruction of the valves, followed by fibrous scarring
What is fish mouth stenosis
fibrous adherence across the commissures produce a fish mouth stenosis due to the mitral valve which are shortened and thickened, and become fused to one another in RHD -> stenosis
What side of the heart is usually affected in RHD?
left
How do valve changes in RHD affect the heart?
valves become incompetent and do not close completely during systole (valvular insufficiency)- regurg
can also become stenotic
What is cor pulmonale?
right heart failure
What is responsible for the most deaths after the acute phase in RHD?
endocarditis
What are the extracardiac findings in RHD?
Polyarthritis
Subcutaneous Nodules
erythema marginatum
Sydenhams chorea
Describe erythema marginatum
maculopapular erythematous rash mostly on truck and extremities, spares faces
Lab findings in RHD?
increasing ASO titers
elevated ESR and CRP (nonspecific inflammatory marker)
Lab findings in RHD?
increasing ASO titers
elevated ESR and CRP,
leukocytosis (nonspecific inflammatory marker)
How is dx of RHD made?
based on Jones Criteria (2 M or 1M and 2m)
Major criteria: pancarditits, polycarditis, syndenhams choarea, subcutaneous nodules, erythema marginatum
Minor: hx RF, fever, arthragias, ECG changes, evidence of prior strep
Complications of RHD?
secondary bacteria infetion, valvular vegetation -> emboli-> infarct
Tx of RHD?
cant be cured
valve replacement
prompt tx of strep pharyngitis
What is infective endocarditis?
bacterial infections of cardiac valves causing erosions of the surface layers, allowing entry of bacteria into the valve
characteristics of subacute bacterial endocarditis?
slower, less virulent disease (St. viridans)
can cause inf. in previously abn. heart valves…..
Pre-exisiting causes for endocarditis?
Artificial valves, congenital defects, degenerative calcified valvular stenosis, bicuspid aortic valves, myxomatous mitral valve (MVP)
Which organism is responsible for the most cases of prosthetic valve endocarditis?
staph epidermidis
others: enterococci, gram - bacteria and fungi
Clinical features of infective endocarditis
fever
quick onset chills, night sweats, weakness
murmur
SBE: low grade fever, fatigue, flu sxs
complications of infective endocarditis
Septic embolic episodes
CHF….
IE dx?
clinical presentation
US, + blood cultures
What is pericarditis?
Inflammation of the pericardium, either the visceral or parietal layers (inflammation of one causes inflammation of the other)
What causes pericarditis?
bacteria, viruses, rarely fungi, severe autoimmune disease (SLE), CKD (uremia-> waste products in blood ->inflammation)
How does pericarditis appear pathologically?
always associated with exudation of fluid into the pericardial sac
serous pericarditis (viral): clear/yellow fluid
Bacterial: purulent exudate
serofibrinous exudate in pericarditis is associated with…
more severe damage, such as in RF or in early bacterial infections
What does fibrinous pericarditis look like?
surface of heart is covered with shaggy, yellowish layers of fibrin btwn the 2 layers of the pericardial sac
bread and butter!
What is myocarditis?
acute inflammation of the myocardium, typically caused by viruses
-most often due to Coxsacki B virus
In pancarditis…
all 3 layers of the heart are affected
Can bacteria causes myocarditis?
relatively rare, usually due to a secondary disorder (diphtheria, meningococcus) or other causes such as radiation, and hypersensitivity rxns.
How do viruses cause myocardial disease?
viruses cannot survive outside of the cells so they must invade the myocardium, damaging the myocardial cells
The myocardium is also invaded by t-lymphocytes which secrete lymphokines interleukins and TNF
Why is it bad that lymphokines are secreted in myocarditis?
they are supposed to kill the virus but also destroy the myocardial cells, contributing to HF
Pathology in viral myocarditis?
pale and congested areas (where virus was) with mild hypertrophy, bi dilated and generalized hypokineasis of myocardium = Tiger effect
Flabby and dilated!
What does viral myocarditis look like histologically?
patchy, diffuse interstitial infiltrate mostly composed of T-lymphocytes and macrophages
inflammatory cells often surround ind. myocytes with focal/patchy acute myocyte necrosis
Myocarditis presentation?
mild fever, SOB, malaise
if severe: HF sxs
males > females
Myocarditis dx and tx
definitive: endomyocardial biopsy
supportive care
What is the etiology of atherosclerosis?
first damage at interface btwn blood and arterial wall + deposition of platelets and serum lipoproteins under the endothelium which stimulates macrophages
What role do platelets play in atherogenesis?
platelets release growth factors -> proliferation of smooth muscle cells in wall of artery -> promotes accumulation of cholesterol and lipids -> LDL transformed to foam cells
What role do macrophages play in atherogenesis?
lesions attract macrophages which take up the released lipids, also secrete cytokines/TNF which cause more damage by stimulating collagen production along with the damaged smooth muscle cells
In atherosclerosis, what is the name for the bulge in the vessel wall?
atheroma
central part: soft and consists of lipids and cellular debris
covered by fibrous tissue that forms a fibrous or surface cap
What is the major complication of the atheroma?
hardening of the vessel
precipitated by local tissue degeneration, lipids released from dead cells attract calcium salts
Risk factors for atherosclerosis?
Age, Sex (male > females), heredity, lipid metabolism, HTN, obesity, DM, smoking, stress
mildest form of atherosclerosis of the aorta
found in young/middle aged ppl
have fatty streaks which are slightly raised fibrotic plaques
progression of fatty streaks in atherosclerosis…
fatty streak-> atheroma -> atheroma may rupture, become calcified and fibrosed -> rigid calcified tube that has a rough, jagged, ulcerated internal surface covered focally with thrombi
Atherosclerosis effect on BP
increases BP, which leads to the formation of aneurysms
Where do aneurysms of the aorta most commonly occur?
in abd aorta, usually clinically silent
most often fusiform, saccular or spindle-shaped
What are small saccular aneurysm at the base of the brain, involving the circle of willis called?
berry aneurysms
Are primary cardiac tumors common?
no but when they occur can result in serious problems
usually benign and are pedunculated (have a stalk)
What are the 3 types of cardiac tumors?
cardiac myxomas, rhabdomyomas, metastatic tumors
Describe cardiac myxomas
most common primary tumor
most arise from left atrium
appears as a glistening, gelatinous, polypoid mass, usually 5-6cm with a short stalk
sometimes mobile and can obstruct the mitral valve orifice
1/3 of pts with a myxoma of the LA or LV die of…
embolization of the tumor to the brain
surgical removal is usually successful
What is a rhabdomyoma and where are they found?
most common primary cardiac tumor in infants and children and forms nodular masses in the myocardium
almost all are multiple and involve both ventricles
What do rhabdomyomas look like grossly?
pale gray masses, up to several cm
What cancers typically metastasize to the heart?
lung, breast, GI
lymphomas, leukemias and malignant melanomas may also
metastatic CA of the myocardium can result in manifestations of….
restrictive cardiomyopathy
What is CAD?
artherosclerosis of the coronaries which presents as myocardial ischemia due to the narrowing by atherosclerosis or sudden onset due to thrombus
What is an anterior wall infarct typically caused by?
occlusion of the LAD
What is an infarct of the lateral wall of LV usually caused by?
occlusion of the left circumflex coronary artery
Where do occlusions most often occur?
LAD, RCA, left circumflex a.
What is an acute MI?
rapid sudden occlusion of a coronary a.
80-90% of transmural infarcts are caused by thrombosis of a coronary a.
Define transmural
all 3 layers of the heart are necrotic
Cause of sudden cardiac death?
(occurs in 25% of MI)
usually due to major arrhythmia (vfib) or later complete heart block and pump failure
Grossly, what are the 2 types of MIs?
- Transmural: all 3 layers of heart
2. Subendocardial/intramural: infarction is usually concentric around the subendocardial layer of the LV
