Pathology Flashcards
Atherosclerosis
Chronic progressive inflammatory process of multifactorial etiology affecting small and large arteries.
- Formation of fibrofatty plaques
- Stenosis of vascular lumen
- Ass. degenerative changes in vascular media
Atherosclerosis
AHA Classification
-
Type I ⇒ fatty dot
- Foam cells
-
Type II ⇒ fatty streak
- Intracellular lipid
-
Type III ⇒ intermediate
- Small extracellular lipid pools
-
Type IV ⇒ atheroma
- Lipid core
-
Type V ⇒ fibroatheroma
- Fibrotic layer, calcification, or fibrosis
-
Type VI ⇒ complicated lesion
- Surface disruption
Fatty Streaks
- 1st stage of atherosclerosis
- Foam cells, T cells, and small amount of extracelluar lipids
- Found in aorta of all children > 10 y/o
- Not all will become plaques
Plaques
-
Cellular constiuents
-
Endothelial cells/ECM ⇒ injury starts process
- ↑ Adhesion molecules
- Becomes leaky
-
Lymphocytes, mainly T cells
- Mediate chronic inflammation
- Secrete IFN-𝛾 to activate MΦ
-
MΦ
- Pro-inflammatory ⇒ IL-1, TNF
- Oxidize LDL
-
Lipid core
- Oxidized LDL toxic to endothelium and VSMC
- Ingested by MΦ
- ↑ Expression of adhesion molecules
- Promotes/keeps MΦ there
-
Vascular smooth muscle cells (VSMC)
- Migrate in from vascular media
- Proliferate and secrete ECM proteins
-
Endothelial cells/ECM ⇒ injury starts process
- Common places
- Elastic arteries
- Aorta, carotid, iliac
- Large and medium muscular arteries
- Coronary, popliteal
- Elastic arteries
Complicated Lesions
Erosion, ulceration, rupture
Atherosclerotic
Thrombus Formation
- Clot forms on the plaque surface
- May lead to
- ↑ Stenosis
- Plaque rupture / fragmentation ⇒ embolization ⇒ distal ischemia
Plaque Hemorrhage
- Bleeding can occur within the plaque
- Results in rapid enlargement
- If plaque does not rupture ⇒ blood clots and organizes over time
Aneurysmal Dilation
- Results from thinning/weakening of arterial media
- Weakened portion expands under arterial pressure
- Creates an outpouching
- Often leads to thrombus formation
Atherosclerosis
Pathogenesis
Response to injury hypothesis:
- Endothelial injury
- Inflammation
- Accumulaiton of lipoproteins
- Oxidation of lipoproteins
- Adhesion of monocytes and platelets
- Migration and proliferation of VSMCs
Endothelial Injury
- Endothelial injury ⇒ endothelial cell activation
- Multifactorial etiology
- Turbulent blood flow
- Hypercholesterolemia
- Activated endothelial cells
- ↑ Permeabiity
- ↑ Leukocyte adhesion
- ∆ Gene expression
Endothelial Dysfunction
Atherosclerosis
Role of Inflammation
- Injured endothelium ⇒ adhesion molecule expression ⇒ recruitment of monocytes and T-cells
- Monocytes ⇒ MΦ
- MΦ remove lipids ⇒ foam cells
- Lesion progression
Atherosclerosis
Role of Lipoproteins
- Chronic HLD may impair endothelial cell function
- Lipoproteins accumulate @ foci of ↑ EC permeability
- Lipids + free radicals ⇒ oxidized LDL ⇒ ingested by MΦ ⇒ foam cells
- Consequences
- Stenosis
- Thrombosis
- Vasoconstriction
-
Acute plaque change
- Rupture/fissuring ⇒ exposes highly thrombogenic plaque constituents
- Erosion/ulcration ⇒ exposes thrombogenic subendothelial BM to blood
- Hemorrhage into atheroma ⇒ expands volume
Atherosclerosis
Sequelae
Aneurysm
Formation
Most common location ⇒ abdominal aorta
(Distal to renal aa / Proximal to bifurcation)
Aneurysm
Classification
By shape and size:
Dissection
Occurs when blood seperates laminar planes of the media.
Forms a blood-filled channel within the vessel wall.
CVD
Risk Factors
- HTN
- HLD
- Smoking
- Obesity
- DM
- Age
- Sex ⇒ estrogen protective
- Genetics
Hypertension
Effects on Atherosclerosis
HTN associated with:
-
Hyaline arteriolosclerosis
- Homogenous pink hyaline thickening and luminal narrowing
-
Hyperplastic arteriolosclerosis
- Seen with malignant HTN
- Lesion called ‘onion-skinning’
DM
Effects on Atherosclerosis
- Causes macrovascular and microvascular disease
- ↑ Risk of MI and stroke
- 100x ↑ risk of atherosclerosis-induced gangrene of LE
- Complex mechanism
- Advanced glycation end products (AGEs) ⇒ accelerate endothelial injury
- Intracellular hyperglycemia ⇒ ↑ susceptibility to oxidative stress
- Insulin’s vasoprotective effects
Hypoxemia
Failure to deliver adequately oxygenated blood to tissues
Ischemia
Hypoxemia & inadequate removal of metabolites
Subendocardial MI
Pathogenesis
- Subendocardium least well perfused
- Relies on diffusion from ventricular space
- Can be precipitated by shock from bleeding or sepsis
MI Pathology
Overview
2-4 Hours Post-MI
Can only see areas of infarction with TTC staining
12 Hours Post-MI
- Micro
- Wavy fibers
- Pyknosis
- Hyperesosinophilia
- Hemorrhage
- Gross
- Mottling
24 Hours Post-MI
- Left
- Pyknosis
- Hypereosinophilia
- Few PMNs
- Right
- Dark contraction bands
- Nuclei absent
- Acute inflammation starting
2 Days Post-MI
- PMNs infiltrate
- Loss of striations
- Loss of nuclei
3-4 Days Post-MI
Inflammatory cells including MΦ
Necrotic myocytes
3-7 Days Post-MI
- Hyperemic border
- Depressed sunken yellow area
- Highest risk for rupture of the infarcted area
1 Week Post-MI
Very early granulation tissue
7-10 Days Post-MI
MΦ
Numerous capillaries
Immature collagen
2 Weeks Post-MI
More developed vessels
↑ Collagen
Maturing granulation tissue
2-4 Weeks Post-MI
Continued in-growth of capillaries
Fibroblasts w/ collagen deposition
2 Months Post-MI
Healed MI
Reperfusion Injury
- Generally reperfusion beneficial
-
“New” cellular injury may occur
- Infiltrating WBCs generate oxygen free radicals
- Apoptosis
- Microvascular injury ⇒ hemorrhage and endothelial cell swelling
- Occlusion of capillaries ⇒ prevent reperfusion
- Contraction band necrosis
MI
Mortality
- ½ of all deaths due to acute MI occur within 1 hour of onset
- 30% overall mortality in the 1st year
-
Risk factors:
- Advanced age
- Female gender
- DM
- Previous MI
- 75% have post-MI complications
Complications of MI
Myocardial Rupture
Full thickness hole through part of the heart
- Ventricular free wall
- Hemopericardium ⇒ cardiac tamponade
- Highest risk 3-7 days post MI
- Ventricular septum
- L to R shunt ⇒ murmur and CHF
- Papillary muscle
- Acute, severe MR
Pericarditis 2/2 MI
- Fibrinous or fibrino-hemorrhagic ⇒ bread and butter appearance
- Usu. occurs 2-3 days post transmural MI
- Usually resolves
Right Ventricular Infarct
2/2 MI
Usually seen with MI of the adjacent posterior LV and ventricular septum
Extension
New necrosis adjacent to an existing infarct
Expansion
Stretching, thinning, and dilation of the infarcted region.
Seen most often in anteroseptal infarcts.
Mural Thrombus
Focal abnormal in contraction ⇒ stasis
Endocardial damage ⇒ thrombogenic surface
Ventricular Aneurysm
- Late complication
- Bounded by scarred myocardium
- Usually from large anteroseptal MI that has undergone expansion
- Bulges during systole
- Rupture does not occur
- Complications
- Mural thrombus
- Arrhythmias
- Heart failure
Chronic Ischemic Heart Disease
(CIHD)
“Progressive late heart failure”
- Exhaust compensatory hypertrophy of viable myocardium ⇒ cardiac decompensation
- Slow progressive onset of CHF s/p MI
- Accounts for ~ 50% of cardiac transplants
- Enlarged, heavy heart with LV hypertrophy and dilation
Sudden Cardiac Death
- 80-90% due to IHD
- Typically due to a lethal arrhythmia
- Increased cardiac mass is an independent risk factor
- Prognosis improved w/ automatic defibrillators
Atrial Natriuretic Peptide
(ANP)
- Produced by atrial cells
- Causes:
- Vasodilation
- Natriuresis
- Diuresis
Cardiac
Gap Junctions
- Ensure synchronous contraction through electrical coupling
- Ischemia and myocardial disease ⇒ abnl spatial distribution of gap junctions
- Contributes to electromechanical dysfunction and heart failure
Cardiomyopathy
Structural Changes
-
Chambers
- ↑ LA cavity size
- ↓ LV cavity size
- Sigmoid septum
-
Valves
- AV calcification
- MV annular calcification
- Fibrosis of leaflets
- Buckling of mitral leaflets towards LA
- Lambl excrescences ⇒ small filiform processs on the closure lines of aortic and mitral valves
-
Epicardial coronary arteries
- Tortuosity
- ↑ Cross-sectional luminal area
- Calcification
- Atherosclerosis
-
Myocardium
- ↑ Mass
- ↑ Subepicardial fat)
- Brown atropy
- Lipofuscin deposition
- Basophilic degeneration (by-product of glycogen metabolism
- Amyloid deposits
-
Aorta
- Dilated ascending aorta with rightward shift
- Elongated thoracic aorta
- Sinotubular junction calcification
- Elastic fragmentation and collagen accumulation
- Atherosclerosis
Heart Failure
Pathophysiology
6 principal mechanisms underlie heart failure:
- Pump failure
- Obstruction to flow
- Regurgitant flow
- Shunted flow
- Conduction abnormalities
- Rupture of heart or major vessel
Cardiomyopathy
A primary abnormality of the myocardium.
- Primary vs secondary
- Classified based on morphology
- Dilated
- Hypertrophic
- Restrictive
Dilated Cardiomyopathy
“Congestive cardiomyopathy”
- Progressive dilation and contractile dysfunciton
- Most common form ⇒ 90%
- Onset 20-50 y/o
Etiology of Dilated Cardiomyopathy
-
Familial ⇒ 25-35%
- Most AD w/ variable penetrance
- Typically affect cytoskeleton
- Also proteins of sarcomere, mitocondria, nuclear envelope
-
X-linked form
- Mutation in dystrophin gene
- Presents in teens to early 20’s
- Rapidly progressive
-
Acquired
-
Toxin-induced
- ETOH and acetaldehyde directly toxic to myocardium
- Thiamine deficiency may contribute
- Chemotherapeutic agents like doxorubicin
- ETOH and acetaldehyde directly toxic to myocardium
-
Inflammatory ⇒ myocarditis
- Coxsackie B virus and other enteroviruses
-
Pregnancy associated
- Occurs in late pregnancy or weeks-months postpartum
- HTN, volume overload, nutritional deficiencies, immune rxn may be involved
-
Toxin-induced
Dilated Cardiomyopathy
Appearance
- Gross
- Enlarged globular heart
- Usu. all chambers dilated
- Micro
- Myocyte hypertrophy and stretching
- Nulcear enlargement
- Interstitial fibrosis
- Inflammatory infiltrates
Hypertrophic Cardiomyopathy
“Idiopathic hypertrophic subaortic stenosis (IHSS)”
- Symmetic and asymmetrical patterns
- 30% w/ outflow obstruction
- Loss of compliance ⇒ diastolic dysfunction
- Systolic function usually hyperdynamic
-
Etiology:
- Familial ⇒ 50%
- Friedreich ataxia
- Storage diseases
- Infants of diabetic mothers
- Pathophysiology: mutations in structural proteins of scarcomere ⇒ diastolic dysfunction, myocyte hypertrophy, and disarray
Familial Hypertrophic Cardiomyopathy
- Mutations in structural proteins of sarcomere
- β myosin heavy chain most common
- Autosomal dominant
Hypertrophic Cardiomyopathy
Mimics
- HTN heart disease w/ age related subaortic septal hypertrophy
- Aortic stenosis
- Amyloidosis
Hypertrophic Cardiomyopathy
Morphology
- LVH affects septum most
- Endocardial fibrosis
- Myocyte hypertrophy and disarry with interstitial fibrosis
Restrictive Cardiomyopathy
- Loss of compliance ⇒ diastolic dysfunction
- Least common type
- Often associated with systemic disease
- Causes:
-
Direct
- Toxic
- Methylsergide
- Anorectic agents
- Radiation
- Infectious
- Infiltration
- Genetic
- Idiopathic
- Toxic
-
Indirect: infiltration by something other than cardaic muscle
- Glycogen storage diseases
- Amyloidosis
- Hemachromatosis
- Sarcoidosis
-
Direct
Secondary Causes of Cardiomyopathy
- Often d/t compensatory changes in the heart
- CO doesn’t meet demand
- ↑ Peripheral resistance
- Volume overload
- Cardiac dysfunction
- CO doesn’t meet demand
Compensatory Cardiac Hypertrophy
Pattern dependent on etiology.
-
Concentric hypertrophy ⇒ seen with conditions that ↑ afterload
- HTN
- Aortic stenosis
-
Non-concentric / Eccentric hypertrophy ⇒ seen with volume overload
- ↓ Capillary to myocyte ratio
- ↑ Fibrous tissue
- Abnormal protein synthesis
Cardiac Hypertrophy & Dilation
Pathophysiology
Heart Failure
Pathophysiology
CO insufficient to meet requirements of peripheral tissues.
- HTN, valvular disease, MI, etc ⇒ ↑ cardiac work
- ↑ Wall stretch ⇒ hypertrophy and/or dilation
- ↓ Renal perfusion ⇒ RAAS activation ⇒ sodium and salt retention
- Down regulation of neurohumoral receptors
-
May be due to:
- Loss of blood, arrhythmia, obstructed flow, regurg, or primary pump failure
Heart Failure
Clinical Presentation
Left-sided Heart Failure
- Causes:
- Ischemic heart disease
- HTN
- AV or MV disease
- Non-ischemic myocardial diseases
- Effects:
- Congestion of pulmonary vasculature
- ↓ Peripheral blood pressure and flow
- Sequelae of left HF:
- Secondary atrial enlargement
- Pulmonary congestion and edema
- ↓ Renal perfusion
- Cerebral hypoxia
Pulmonary Edema
- Leakage of congested capillaries into alveolar spaces
- Results in hemosiderin deposition in MΦ ⇒ siderophages (“Heart failure cells”)
Right-sided Heart Failure
- Causes:
- Left-sided HF ⇒ most common
- Cor pulmonale
- Chronic pulmonary HTN
- Effects:
- Passive congestion of liver
- Renal congestion
- Pleural effusions
- Anasarca
- RVH
Biventricular Heart Failure
- Many pts have right and left HF
- Treatment
- Diuretics ⇒ ↓ fluid overload
- ACEi ⇒ ⊗ RAAS
- β-blockers ⇒ ↓ systemic vascular resistance
Farmingham Criteria
Dx CHF
CHF
Diagnostic Tests
Important for management, diagnosis is clinical.
- Kidney function
- Electrolytes
- CXR
- BNP
- ECHO
Left-sided HF
Classification
-
Diastolic HF
- LVEF > 50%
- Thickened and stiff chambers
- Heart can’t fill
-
Systolic HF
- LVEF < 40%
- Dilated and thin chambers
- Heart can’t pump
Diastolic Heart Failure
“CHF w/ preserved systolic function”
- More common
- Seen in older pts with hx of HTN
- Stiff ventricles with impaired filling leading to inadequate pumping
- Sensitive to HR and volume overload
- Acute presents with similar sx to systolic HF
- SOB, orthopnea, PND, edema
- Management
- Acutely treat with diuresis
- Long-term goal to control BP
Systolic Heart Failure
“CHF with reduced LVEF”
- Generally due to cardiomyopathies
- Different types
-
Ischemic heart disease
- CAD
- MI
- CABG
-
Non-ischemic cardiomyopathies
- Familial
- Viral
- Drug and ETOH
- Hypo or hyper thyroid disease
- Chemotherapy (Doxorubicin and Herceptin)
- Toxins (cobalt)
- Infections like HIV
- Valvular heart disease
-
Ischemic heart disease
Heart Failure
Long-term Management
- Manage modifiable factors
- Medications
- Beta-blockers
- ACEi
- Mineralocorticoid inhibitors
- Patient education
- Avoid NSAIDS
Heart Failure
Causes of Decompensation
- Non-compliance ⇒ leading cause
- Ischemia
- Inadequate treatment
- Arrhythmias
- Miscellaneous
- HTN
- No definite factor
Cardiac Teratogens
- Maternal rubella infection ⇒ PDA
- Environmental acquired congenital heart defect
- ETOH
- Thalidomide
- Maternal DM
Trisomy 21 (Down’s) is associated with…
- Atrioventricular septal defects (endocardial cushion defect)
- VSD
- ASD
- PDA
Trisomy 18 (Edwards) is associated with…
- VSD
- Double outlet right ventricle
- PDA
Trisomy 18 (Patau) is associated with…
VSD, ASD, PDA
Turner syndrome (XO) is associated with…
aortic coarctation
Marfan’s syndrome is associated with…
Mitral valve prolapse
Aortic root dilatation
DiGeorge Syndrome is associated with…
Truncus arteriosus
Thrombocytopenia Absent Radius Syndrome (TAR) is associated with…
Tetralogy of Fallot
William’s Syndrome is associated with…
Supravalvar aortic and pumonary stenosis
Cyanosis Tardive
Congenital heart defects with initial L→R shunt and later development of a R→L shunt
Eisenmenger’s Complex
VSD with reversal of flow due to pulmonary HTN
Occures when pulmonary pressure = systemic pressure
Atrial Septal Defect
(ASD)
- Abnormal opening in atrial septum allowing communication between left and right atria
- 3 types classified by location on septum
-
Secundum ASD ⇒ 90%
- @ Fossa ovale
-
Primum ASD ⇒ 5%
- Near AV valves
- Usually ass. w/ cleft anterior mitral leaflet
-
Sinus venous ASD ⇒ 5%
- Near entrance of SVC
- Usu. w/ anomalous connections of right pulmonary veins
-
Secundum ASD ⇒ 90%
- Pulmonary blood flow 2-4x nl
- Most isolated well tolerated ⇒ asymptomatic till 30 y/o
- Mumur often present
Ventricular Septal Defect
(VSD)
- Most common congenital cardiac anomaly
- Described by location and size
- Membranous vs muscular
- 50% of small muscular VSD close spontaneously
- Large defects usu. membranous or infundibular
- Stay open with sign. shunt
- L to R shunt ⇒ RV dilation and hypertrophy
- Eisenmenger’s syndrome
PDA
- 90% are isolated
- Most w/o functional difficulties @ birth
- Harsh “machine-line” murmur
- Initial L to R shunt ⇒ Eisenmenger
- Close ASAP
- Sometimes need to keep open ⇒ Prostaglandin E
Atrioventricular Septal Defect (AVSD)
-
From abnl development of embryologic AV canal
- Superior and inferior cushions fail to fuse
- Incomplete closure of AV septum
- Inadequate formation of tricuspid and mitral valves
- In complete form ⇒ all 4 chambers freely communicate
- > ⅓ with complete AVSD have Downs
Tetralogy of Fallot
- Most common cyanotic congenital heart disease
- 10% of all CHD
- Features:
- VSD ⇒ membranous, malaligned
-
RV outflow tract obstruction
- Most severe form is pumonary valve atresia
- Aorta overriding septal defect ⇒ dextroposition
- RVH ⇒ compensatory
- Clinical manifestations
- R to L shunt ⇒ cyanosis
- Pulmonary arteries hypoplastic
- Aorta enlarged
- Subpulmonary stenosis protects pulmonary vasculature from pressure overload ⇒ RV failure rare
Truncus Arteriosus
-
Persistent presence of one arterial trunk arising from the ventricles
- Due to failure of separation into pulmonary artery and aorta
- Single great artery receives blood from both ventricles
- Accompanied by underlying VSD
- Blood from RV and LV mix ⇒ early systemic cyanosis
- ↑ Pulmonary blood flow ⇒ risk of irreversible pulmonary HTN
Transposition of the Great Vessels
- Discordant ventriculo-arterial connections
- LV ⇒ pulmonary artery / RV ⇒ aorta
-
Need mixing of systemic venous and arterial blood to live
- VSD (35%)
- PFO and PDA (65%)
- RVH, LV atrophy
- Fix with arterial switch operation
- Need to consider abnl of coronary arteries
Aorta Coarctation
A narrowing, or constriction, in a portion of the aorta.
-
Infantile form
- Tubular hypoplasia of aortic arch proximal to PDA
- Sx early in life
-
Adult form
- Ridge of proliferative intimal tissue usually in a post-ductal position
- Ass. with male sex except for Turner’s syndrome
- Bounding pulses in BUE
- Can develop collaterals via enlarged intercostal and internal mammary arteries
- Visible erosions “notching” on underside of ribs on CXR
Pulmonary Stenosis and Atresia
-
Obstruction @ pulmonary valve
- Varied severity
- Isolated or part of complex
-
Clinical manifestations:
- RVH
- ± Post-stenotic dilation of pulmonary artery
- ± Pulmonary trunk hypoplasia
-
Complete atresia of PA ⇒ no communication b/t RV and lungs
- See hypoplastic RV and ASD
Aortic Stenosis and Atresia
-
Valvular AS
- Cusps hypoplastic, dysplastic, or abnl #
- Less severe forms compatible with life
- 80% isolated
- May see dense, porcelain-like endocardial fibroelastosis of LV
-
Subaortic stenosis
- Thickened band (discrete type) or collar (tunnel type) of dense endocardial fibrous tissue
- Below level of the cusps
-
Supravalvular AS
- Ascending aortic wall thickened ⇒ luminal constriction
- May be related to developmental d/o affecting multiple organ systems
- Includes hypercalcemia of infancy (Williams syndrome)
- Can be caused by elastin mutations
Hypoplastic Left Heart Syndrome
Constellation of findings:
- Severe congenital valvular aortic stenosis/atresia
- LVOT obstruction ⇒ LV and ascending aorta hypoplasia
- PDA ⇒ allows flow into aorta and coronary arteries
- Nearly always fatal in first week of life when ductus closes
Causes of Myocarditis
Most cases are viral.
Dallas Criteria
Classifies myocarditis based on endomyocardial biopsy findings.
Types of Myocarditis
- Lymphocytic myocarditis
- Hypersensitivity myocarditis
- Giant cell myocarditis
- Sarcoid myocarditis
- Infectious myocarditis
Lymphocytic Myocarditis
- Most common form
- Associated with myocyte injury
- Most cases are viral
- Focal, patchy, or diffuse pattern
- Gross appearance
- Normal ⇒ Enlarged and dlidated with mottling
- Dx with clinical findings, serology, histopathology, ISH, molecular probes, and PCR
Lymphocytic Myocarditis
Causes
Hypersensitivity Myocarditis
-
Etiologies
-
Typically caused by drugs
- Sulfonamides, methyldopa, PCN
- Parasitic infections
- Taenia, Echinococcus, Schistosoma, Tricinella, Toxoplasma, Trypanosomiasis
- Hypereosinophilic syndromes
- Asthmatic bronchitis
-
Typically caused by drugs
- Eosinopril-rich inflammatory infiltrate in myocardium
Infectious Myocarditis
- Chagas disease due to Trypanosoma cruzii
- Toxoplasma
- Diphtheria
- Trichinosis
Granulomatous Myocarditis
Characterized by infiltrates of histiocytes and lymphocytes with granuloma formation.
- Idiopathic
- Sarcoidosis
- Granulomatous infections
- Mycobacteria and fungi
- See necrotizing granulomas
- Hypersensitivity
- Rheumatoid disases
- Rheumatic fever
Giant Cell Myocarditis
- Unknown etiology
- Rapidly progressive
- Frequently fatal
- Mixed inflammatory infiltrate including multinucleated giant cells
- Multifocal myocyte necrosis
- No granulomas
Neutrophilic Myocarditis
- Causes
- Bacteria and some fungi
- Due to generalized sepsis or direct spread from infective endocarditis
- Early viral and idiopathic myocarditis
- Ischemia/Infarct
Myocarditis
Clinical Features
- May be asymptomatic with no sequelae
- May result in acute heart failure, arrhythmia, or sudden death
- Most have fatigue, dyspnea, palpitations, precordial discomfort, fever
- Dilated cardiomyopathy may result over time
Pericardial Disease
- Pericardial disorders can cause
- Fluid accumulation
- Inflammation
- Fibrous constriction
- Usually associated with disease elsewhere in the heart or systemic disease
- Isolated pericardial disease rare
Pericardial Effusion
- Most often develop d/t pericarditis
- Exceptions include cardiac rupture and myxedema (hypothryoidism)
- Pericardium may be distended by:
- Serous fluid
- Blood ⇒ hemopericardium
- Pus ⇒ purulent pericarditis
- Gas/air ⇒ pneumopericardium
Chronic Pericardial Effusion
Slowly accumulating effusions dilate the pericardium.
- Can reach > 500 ml and remain asymptomatic
- CXR ⇒ globular enlargement of the heart shadow
- EKG ⇒ low-voltage QRS complexes in all 6 limb leads
Acute Pericardial Effusion
Rapidly developing fluid collections.
-
200-300 ml may cause cardiac tamponade
- Compress atria and venae cavae
- Can compress ventricles
- Cardiac filling restricted
- Seen with
- Hemopericardium d/t ruptured MI site
- Proximal aortic dissection
Cardiac Tamponade
Etiologies
- Hemopericardium d/t ventricular wall rupture s/p MI
- Proximal aortic dissection
- Bacterial or fungal infections
- HIV-associated infections
-
Neoplastic involvement
- ~ 20% of large effusions with no obvious cause constitute the initial presentation of unrecognized cancer
Cardiac Tamponade
Pathogenesis
Unless intrapericardial pressure immediately decreased, pulmonary blood flow stops and cardiac arrest follows.
Cardiac Tamponade
Clinical Presentation
- Dyspnea and tachypnea
- Pericardial pain
- Diaphoresis
- Peripheral cyanosis
- Beck’s triad ⇒ hypotension, muffled heart sounds, JVD
- Paradoxical pulse ⇒ abnormally large drop in systemic arterial pressure during inspiration
-
Varying degrees of reduced CO and shock
- Diaphoresis, cool extremities, depressed sensorium
Electrical Alternans
- Occurs with pericardial effusion and tamponade
- Beat-to-beat shift in QRS axis
- Associated with mechanical swinging of the heart
- Electrical alternans + sinus tach virtually dx of cardiac tamponade
Pneumopericardium
- Air within the pleural cavity
- Can lead to cardiac tamponade
- Causes
- Complication of respiratory therapy in infants
- Seen with pneumothorax and pneumomediastinum
- Spontaneously in asthma
- Blunt chest trauma
- S/p pericardiectomy
- Complication of respiratory therapy in infants
Causes of Pericarditis
Pericarditis
Clinical Presentation
-
Severe pleuritic pain in anterior chest
- May radiate to arms and back
-
Pericardial friction rub
- Best heart at the left sternal border at end expiration
- EKG ⇒ diffuse ST elevations in all leads
Acute Pericarditis
- Most common types:
- Fibrinous ⇒ “dry’, little or no serious effusion
- Serofibrinous ⇒ “wet”, ass. w/ serous effusion
- Causes:
-
Noninfectious inflammatory diseases
- Rheumatic fever
- Dressler syndrome
- Uremia
- SLE, Scleroderma
- Tumors
-
Infection of contiguous tissues
- Preceding viral infection
- Other causes:
- 1-3 days post MI
- Radiation
- Post-surgical
-
Noninfectious inflammatory diseases
Purulent/Suppurative Pericarditis
-
Due to infection of pericardial space
- Direct extension from adjacent tissues
- Hematogenous or lymphatic spread
- Inoculation during procedure
- Up to 500 ml of exudate
- Serosa reddened and granular
- Extension ⇒ mediastinopericarditis
- Usu. results in organization and scarring ⇒ constrictive pericarditis
Hemorrhagic Pericarditis
- Most often caused by malignancy
- Bacterial infections esp. Tb
- Pts w/ bleeding diathesis
- S/p cardiac surgery
Caseous Pericarditis
- Presumed to be Tb until proven otherwise
- Rarely fungal infections
- Occurs by direct spread from Tb foci
- Frequently progresses to disabling, fibrocalcific, chronic constrictice pericarditis
Chronic Pericarditis
- Can develop from any type of acute pericarditis
- Fibrous thickenings ⇒ soldier’s plaque
- Delicate, stringy adhesions may damage pericardial sac ⇒ adhesive pericarditis
- Rarely interferes with cardiac function
Adhesive Mediastinopericarditis
- Obliteration of pericardial sac with adherence of outer pericardium to surrounding structures
- Pulls during systole ⇒ cardiac strain
- Inc. workload ⇒ hypertrophy and dilation
Constrictive Pericarditis
- Fusion of visceral and parietal layers ⇒ thick fibrous scar
- Compresses the heart
- Prevents hypertrophy & dilation
- Heart cannot respond to inc. peripheral demand
- See DOE, weight loss, fatigue, ankle edema
- May require pericardiectomy
- Most common w/ pericardial disease d/t:
- Tb
- Radiation therapy
- Prior cardiac surgery
- Chest trauma
- Uremia
- Metastatic tumor
- Develops months to years after acute insult
Cardiac Tumors
-
Primary tumors
- Much lower incidence
- Myxoma most common
-
Metastatic tumors
- Far more common
- Can originate from anywhere
- Sarcomas and germ cell tumors common
Myxoma
- Most common primary tumor in adults
- 90% in atria
- L:R = 4:1
- Derived from multipotent mesenchymal cells
- Gelatinous “myxoid” consistency with soft, irregular surface
Myxoma
Histology
- Abundant myxoid matrix
- Stellate, endothelia, SM, and undiff. cells
- Inflammation and hemorrhage may be present
Lipomas
- Occur in subepicardium or subendocardium > myocardium
- Most in LV, RA, or atrial septum
- Lipomatous hamartoma of cardiac valves ⇒ rare
- Gross and micro appearance of adipose tissue
Rhabdomyoma
- Most common primary cardiac tumor in kids
- Protrude into ventricle
- Often seen with tuberous sclerosis
- May cause outflow obstruction
- Composed of skeletal muscle dervied cells
- Spider cells
Angiosarcoma
- Malignant vascular tumor
- Anastomosing vascular channels lined by atypical cells
- Hemorrhage and necrosis common
