Cardiac Pathophysiology I Flashcards
What is pericarditis?
Inflammation of the pericardium, either visceral or parietal layer
What are causes of pericarditis? (6)
- bacteria, viruses, fungi (rare)
- Rheumatic heart disease
- Lupus (SLE)
- Trauma
- Radiation
- open heart surgery
What is serositis?
inflammation of the epicardium, pleural cavity and GI serous compartment
What is the characteristic pathology of pericarditis? What distinguishes viral vs bacterial pericarditis?
- exudation of fluid into the pericardial sac
- viral: serous clear yellow fluid
- bacterial: suppurative/purulent fluid (Staph or Strep bacteria)
What are the two types of exudates found in pericarditis (2)?
- serofibrinous
- fibrinous
Describe Fibrinous Pericarditis?
- BREAD AND BUTTER APPEARANCE
- shaggy yellow layers of fibrin cover the heart
T/F Serofibrinous pericarditis can become fibrinous pericarditis?
TRUE
T/F Fibrinous pericarditis can become adhesive pericarditis if not treated with abx
TRUE
What is tx for constrictive pericarditis?
removal of entire pericardium
What is myocarditis?
-acute inflammation of the myocardium
What causes myocarditis?
- viruses, bacteria, fungi
- rheumatic fever
- lupus
- autoimmune disorders
T/F Over 80% of myocarditis cases are caused by viruses
True
What virus is the most common cause for myocarditis?
Coxsackie B virus
T/F Bacterial myocarditis is very common
False- bacterial myocarditis is very rare
What are some causes for bacterial myocarditis (3)?
- myocarditis is secondary to infections such as:
- Diphtheria
- Meningococcal
- Staph endocarditis
How do viruses cause myocarditis?
- viruses invade the myocardial cells and kill the vital cell organelles that lead to cell death
- T -lymphocytes are recruited to the area and release TNF and IL (lymphokines)
- these issues cause the muscle to weaken and eventually leads to CHF
What is the pathology in viral myocarditis (4)?
- TIGGER EFFECT
- pale congested areas
- biventricular dilation
- hypokinesis
What is the clinical presentation of myocarditis (4)?
- SOB
- malaise
- fever
- if severe will show signs of CHF
i. peripheral cyanosis
ii. pulmonary edema
iii. tachycardia
How do you diagnose myocarditis?
- endomyocardial punch biopsy
- access via inserting catheter into neck or femoral vein
- 1-2mm piece is retrieved
What is the etiology of atherosclerosis?
- injury to the blood vessel endothelium all the way to the tunica media
- the injury creates a pocket where LDL and platelets can deposit
- macrophages are recruited to the area to engulf the fat but in the process become foam cells
- platelets secrete growth factors which stimulate the proliferation of smooth muscle cells and tell the smooth muscle cells to uptake lipids (smooth cells begin acting like foam cells)
What is etiology of atherosclerosis continued?
- smooth cells die and release lipids which are degraded and deposited into cholesterol crystals
- Macrophages release TNF and cytokines which induce collagen production
- The collagen production causes the blood vessel to scar and thus harden /sclerosis
What is the name for the primary bulge produced in atherosclerosis?
-atheroma
Describe an atheroma?
- fibrous capsule
- necrotic center -gooey ( contains foam cells, cell debris, and crystals ,the center calcifies over time
What is a major complication of atheromas?
-calcification and hardening of the vessel
What are risk factors for atherosclerosis (9)?
multifactorial!!
- age: elderly affected
- sex: early in life men affected more than women but after menopause women are equally affected due to declining estrogen levels
- hereditary: familial hypercholesterolemia is a defect in LDL receptor and doesn’t lipids to be uptaken by the liver so it floats in the blood
- Lipid metabolism
- HTN: hemodynamic forces cause compression of smooth cells that cause the to release cytokines and begins the cascade but this is not well understood
- obesity
- diabetes
- smoking: due to nicotine and tar
- Stress
What are the characteristics of aortic atherosclerosis?
- common finding in the elderly
- fatty streaks
- can be local or diffuse
Is BP affected by atheromas?
- Yes
- aorta/vessels cannot expand with changes in BP because it loses elasticity when it becomes calcified and aneurysms form
Where do aneurysms of the aorta most commonly?occur?
abdominal aorta
What is the some serious complications of aneurysms?
- rupture and death by exsanguination
- aortic dissection
- aortic root dissection
T/F Primary cardiac tumors are common?
False- Primary cardiac tumors are not common
Name the three types of cardiac tumors?
- cardiac myxomas
- Rhabdomyomas
- Metastatic tumors
Describe three characteristics of cardiac myxomas?
- most common primary cardiac tumor 35-50%
- most arise from left atrium 75%
- the tumor is a gelatinous glistening polypoid mass with a short stalk and is mobile enough to compress the mitral orifice
Where do cardiac myxomas located?
left atrium- 50% of patients have mitral valve dysfunction
-1/3 of patients with these tumors die of embolization of the tunor ot the brain
What is a Rhabdomyoma? What population is affected by these tumors?
a tumor that forms nodular masses in the myocardium
-infants are more affected by these tumors
Where are Rhabdomyomas located (3)?
- occur in both the left and right ventricles
- 1/3 of patients have involvement in the atria
- 1/2 have tumor projected into the chamber
- pale gray masses
Which cancers metastasize to the heart (5)?
- breast
- lung
- GI
- lymphoma, leukemias
- malignant melanomas
What disease symptoms are mimicked in patients with metastatic cancer?
-restrictive cardiomyopathies symptoms
What is CAD?
- atherosclerosis of coronary arteries causing ischemia to the myocardium
- Chronic ischemia can cause CHF
What does sudden occlusion of a coronary artery cause?
- sudden occlusion causes Myocardial Infarction in a local/regional area
- LAD occlusion: infarct in anterior wall
- Left circumflex occlusion: infarct to lateral wall of left ventricle
- RCA occlusion: infarct in to right ventricle and posterior wall of left ventricle
What % of occlusions occur in the RCA, LAD, and Left circumflex?
LAD: 50%
RCA: 30-40%
Left circumflex: 10-20%
What is pathology of CAD?
- rigid calcified arteries that can be palpated beneath the epicardium
- the wall has calcium salts and cholesterol, clefts
What is a Myocardial Infarction?
-rapid occlusion of a coronary artery
What is the cause of sudden cardiac death (2)?
- patient goes into an arrhythmia v-vib that causes heart block or pump failure
- v-fib can cause clots to form and when the patients is given pressors blood clots travel to brain and patient dies
What are the two types of MI’s (2)?
- transmural involves all three layers of the heart
- intramural/subendocardial: concentric around subendocardial layer of the left ventricle
What are cardiomyopathies (2)?
-heart disease due abnormality in the myocardium
-Dilation: due long standing volume changes
-Hypertrophy: long standing pressure changes
-
Name the three types of cardiomyopathies?
- Dilated
- Hypertrophic
- Restrictive
What are the characteristics of Dilated Cardiomyopathy?
- most common type
- dilated chambers and systolic dysfunction
- EF reduced to less than 25%
- heavy heart is flabby and large with dilation of all chambers
What are the gross findings in dilated cardiomyopathy (2)?
- thin walls will fibrous tissue
- heart is 2-3x the size, very large
T/F Dilated cardiomyopathies do not have a genetic or idiopathic etiology
False- They do have a genetic or idiopathic origin
What is genetic mode of transmission?
-Mostly autosomal dominant
What are the top 5 causes for dilated cardiomyopathies?
- Alcohol #1
- Adriamycin and Cytoxan anticancer drugs
- Viral myocarditis
- pregnancy
- pheochromocytoma
What are the characteristics of hypertrophic cardiomyopathies?
- hypertrophy of LV
- IHSS-heart is large, heavy, and muscular and weighing >1200 grams
What are the gross findings of hypertrophic cardiomyopathy?
-septum has banana shape due hypertrophic muscle
What is restrictive cardiomyopathy?
- impaired ventricular compliance that causes reduced diastolic filling
- preserved EF
- associated with idiopathic, amyloid sarcoidosis or metastatic tumor
- Associated with Radiation
What are the gross
- patchy diffuse interstitial fibrosis
- heart is not enlarged
How do you diagnose cardiomyopathies?
- ECGs
- endomyocardial punch biopsy
What is acute rheumatic fever (2)?
systemic immunological disease due to GABHS/strep pyogenes
-strep bacteria is dead but it leaves behind a protein and patient develops a sensitivity rxn to that protein
How does the immune system cause disease?
the ASO antibodies produced against the strep protein cross react with antigens/cardiolipin in the heart and causes damage to the connective tissue
Who is more susceptible to RHD?
- children ages 9-11
- crowded environments promote the promulgation of Rheumatic fever
What is Rheumatic Heart Disease?
- complication of ARF
- also involves damage to the joints, subcutaneous CT, vessel, and the brain
What is the pathology of RHD (4)?
- non bacterial ( dead bacteria)
- granulomas/aschoff bodies in tissues of the body including the heart
- pancarditis- bread and butter
- vegetations along the mitral valve
What are aschoff bodies?
aggregates of lymphocytes and macrophages with fibroid necrosis
-become granulomatous
What is rheumatic mitral valvulitis?
-small vegetations along the closure of the mitral valve
Why does RHD cause CHF?
-valvular abnormalities
What side of the heart is more affected with RHD?
-left side
What are major extracardiac findings?
-polyarthritis-pain swelling in joint
-subcutaneous nodules-firm non-tender nodules
-erythema marginatum
-
How do you diagnose RHD?
Jones Criteria/Major criteria:
- pancarditis
- “Aschoff” bodies
- polyarthritis
- subcutaneous nodules over the extensor surfaces
- Maculopapular rash
Minor:
- cultures
- hx
- fever
- arthralgias
- EKG signs
- ASLO titers will be positive in recent strep infection
- ESR
-Two major and two minor criteria need to be met
What is the only tx for RHD?
Valve replacement
How are the layers affected in pancarditis RHD (3)?
pericardium-fibrin is deposited and becomes bread and butter in appearance
myocardium-has deposits of aschoff bodies that causes conduction abnormalities
endocardium-has valvular changes like inflammation and ulceration
What happens to ulcerative valves over time?
they grow with fibrin and become large vegetations along the lines of closures of the valve leaflets
What are acute vegetations?
- non bacterial sites of inflammation within the valves that have been replaced by fibrous scarring
- the chordae tendineae have been shortened and thickened and will fuse together
What is fish mouth stenosis?
-fibrous adherence across the commissures of the valve
What happens when the valves don’t close properly, name the two valvular defects?
Mitral Regurgitation/Insufficiency: blood flows black from left ventricle to left atrium during systole
Aortic Regurgitation/Insufficiency: blood flows back from aorta to left ventricle during diastole, this causes increased hypertrophy
What happens when the valves don’t open properly?
Mitral stenosis: blood stagnates in the left atrium which increases the pressure in LA, pulmonary, and right heart= Cor Pulmonale/RHF
Aortic stenosis: blood cannot go through the aorta so it gets backed up into the LV
what is end result of aortic stenosis?
the LV increases EF to counter the resistance of the aortic stenosis, the heart hypertrophies and over time begins to fail. The blood will flow back into the lung and right heart and cause RHF/Cor Pulmonale
