Vascular Pathology Flashcards
What is an AVM?
Arteries and veins without intervening capillaries
“Tangle of worms” with pulsatile arteriovenous shunting with high blood flow is indicative of what?
AVM
AVM causes what type of cardiac failure?
High-output
Due to shunting of blood into venous circulation
In what population does AVM occur more frequently?
Males
When is AVM typically diagnosed?
Childhood
What is a surgically created AVM?
Arteriovenous fistula for hemodialysis or chemotherapy
What AVM can cause hematuria?
AVM of bladder
What are symptoms of an AVM of the brain?
Seizure
Intracerebral hemorrhage
What is a focal abnormality of an artery due to underlying defect in the media?
Berry (saccular) Aneurysm
Where is a berry (saccular) aneurysm typically found?
Anterior cerebral artery
Anterior communicating artery
What are risk factors for berry (saccular) aneurysm?
HTN
Smoking
Berry (saccular) aneurysms are associated with which diseases?
AD Polycystic kidney disease
Marfan syndrome
Ehlers Danlos syndrome
Subarachnoid hemorrhage is associated with what?
Berry (saccular) aneurysm
What are symptoms of a subarachnoid hemorrhage?
Neck pain Vomiting Double vision Seizures LOC
Berry (saccular) aneurysm rupture often happens with what?
Straining with stool
Sexual orgasm
What is a dilation of artery due to infectious process that damages the vessel wall?
Mycotic aneurysm
What are the three causes of mycotic aneurysm?
1) Septic emboli (infective endocarditis)
2) Extension of an adjacent infectious process
3) Circulating organisms directly infecting the arterial wall
What is a focal, irregular thickening of medium and large muscular arteries?
Fibromuscular dysplasia
What arteries does fibromuscular dysplasia typically impact?
Renal
Carotid
Splanchnic
Vertebral
Fibromuscular dysplasia is upregulated in women due to what?
Estrogen
Fibromuscular dysplasia shows what on angiography?
String of beads
What artery does fibromuscular dysplasia most commonly impact?
Renal artery
Renal artery stenosis in fibromuscular dysplasia leads to activation of what?
RAAS
Activiation of RAAS in renal artery stenosis results in what?
Renovascular HTN (bruit sometimes heard)
What maintains blood volume and vascular tone?
Renin-angiotensin-aldosterone system
When is renin released?
Low volume
Low peripheral resistance
Decreased glomerular filtration rate
Where is renin released?
By juxtaglomerular cells in the afferent arterioles in the kidneys
Renin cleaves circulating angiotensinogen to form what?
Angiotensin I
Angiotensin I is cleaved to form angiotensin II by what?
ACE
Angiotensin II does what?
Vasoconstrict
Volume expansion caused the myocardial cells to release what?
Atrial natriuretic peptide
What does atrial natriuretic peptide cause?
Sodium excretion
Vasodilation
Decreased BP
HTN is a risk factor for what?
Atherosclerosis
End organ damage
What are the unmodifiable risk factors for primary HTN?
Age (older)
Genetics (blacks, higher risk)
What are the modifiable risk factors for primary HTN?
Stress
Obesity
Physical inactivity
Increased salt consumption
What are the renal causes of secondary hypertension?
Renovascular disease Renal artery stenosis Fibromuscular dysplasia Atherosclerosis Polycystic kidney disease
What are the endocrine causes of secondary hypertension?
Primary aldosteronism
Cushing syndrome
Pheochromocytoma
What are the cardiovascular causes of secondary hypertension?
Coarctation of the aorta
Primary hyperaldosteronism causes HTN with what?
Hypokalemia
What symptoms are associated with the HTN due to primary alderosteronism?
Neuromuscular changes (weakness, muscle cramps, paraesthesias, visual disturbances)
What are the three causes of hyperaldosteronism?
Bilateral nodular hyperplasia of adrenal gland
Adenoma
Hybrid glomerulosa cells responsive to ACTH
What are the four causes of Cushing syndrome?
Tumor in anterior pituitary
Tumor in adrenal
Paraneoplastic Cushing
Iatrogenic Cushing syndrome (oral steroids)
What is a pheochromocytoma?
Tumor of the chromaffin cells of the adrenal medulla
What is secreted by a pheochromocytoma?
Epinephrine
Norepinephrine
Norepinephrine causes what?
Alpha-1 activation -> peripheral vasoconstriction
Beta-1 activation -> increased cardiac output
Epinephrine causes what?
Beta-1 activation -> increased cardiac output
What are the clinical symptoms of pheochromocytoma?
Paroxysm of elevated blood pressure Tachycardia Palpitations Headache Diaphoresis Tremor
How do you diagnose pheochromocytoma?
Elevation of urinary or plasma metanephrines
What syndrome is pheochromocytomas assocaited with?
MEN 2
What do pheochromocytomas look like on gross examination?
Golden brown color
What is MEN 1?
Pituitary adenoma
Parathyroid hyperplasia
Pancreatic tumors
What is MEN 2A?
Parathyroid hyperplasia
Medullary thyroid carcinoma
Pheochromocytoma
What is MEN 2B?
Mucosal neuromas
Marfanoid body habitus
Medullary thyroid carcinoma
Pheochromocytoma
What is the rule of 10s for pheochromocytomas?
10% are malignant
10% are extraadrenal
10% of sporatic are bilateral
10% are not associated with hypertension
What happens with renal artery stenosis?
HTN
Decreased GFR
Chronic kidney disease
Increased creatinine
What are the two causes of renal artery stenosis?
Atherosclerosis
Fibromuscular dysplasia
What is adult coarctation of the aorta?
Congenital narrowing of the aorta opposite the ligamentum arteriosum
What does adult coarctation of the aorta cause?
HTN in upper extremities
Hypotension in the lower extremities
Limb claudication
What is coarctation of the aorta in adults associated with?
Bicuspid aortic valve
Coarctation of the aorta is most common in what population?
Males
When is a bruit heard?
Significant obstruction of a larger vessel
Where is a bruit heard with renal artery stenosis associated with fibromuscular dysplasia?
Epigastric abdominal bruit which radiates to the back or side
Where is a bruit heard with coarctation of the aorta?
Carotid bruit
Pyelonephritis and polycystic kidney disease can be a secondary cause of what?
HTN
How does parenchymal kidney disease cause hypertension?
Activation of the renin-angiotensin system due to renal ischemia
Why does concentric left ventricular cardiac hypertrophy occur?
Left ventricle is attempted to pump blood against increased vascular resistance
Concentric left ventricular cardiac hypertrophy leads to what?
Cardiomegaly (which then leads to heart failure, which then leads to fluid back up in the lungs, which then leads to dyspnea)
What are heart and aorta effects due to HTN?
Cardiac hypertrophy
Chronic heart failure
Ischemic heart disease
Aortic dissection
What are kidney effects due to HTN?
Proteinuria
What are brain and eye effects due to HTN?
Multi-infarct dementia
Cerebrovascular hemorrhage/strone
Increased intracranial pressure/papilledema (headache/vision changes)
Retinopathy (AV nicking)
What do patients with untreated HTN die from?
Ischemic heart disease/CHF
Stroke
Hyaline arteriosclerosis due to what?
Increased smooth muscle matrix synthesis and plasma protein leakages across damaged endothelium
Which drug class is hyaline arteriosclerosis seen in?
Calineurin inhibitors (T-cell immunosuppressive drug)
What is the hyaline material composed of in hyaline arteriosclerosis?
Precipitated plasma proteins
C3
Hyaline arteriosclerosis can lead to what downstream?
Ischemia
Homogenous pink (hyaline) thickening of the vessel wall leads directly to what?
Luminal narrowing
Hyaline arteriosclerosis manifests as what in the kidney?
Hyaline nephrosclerosis
Hyaline nephrosclerosis causes what?
Impairment of renal blood supply
Ischemic glomerulosclerosis
Leads to RAAS activation -> HTN
What is a hypertensive crisis?
Systolic greater than 180-200
Diastolic greater than 120
What is a hypertensive emergency?
Hypertensive crisis with end organ damage
What end organ damage is seen in hypertensive emergencies?
Renal failure Encephalopathy Acute heart failure Retinal hemorrhages and exudates Papilledema
Papilledema is typically found with what?
Increased CSF pressure
What does the kidney show in hypertensive emergencies?
Necrotizing arteriolitis
Hematuria
Increased creatinine
Renal failure
What is malignant hypertension?
Markedly increased hypertension
Hyaline arteriolosclerosis occurs with what type of hypertension?
Chronic
Hyperplastic arteriolosclerosis occurs with what type of hypertension?
Severe
In hyperplastic arteriolosclerosis the smooth muscle forms what?
Concentric lamellations with a thickened reduplicated basement membrane
“Onion skinning” is found in what type of arteriolosclerosis?
Hyperplastic
What accompanies lamellations in malignant hypertension?
Fibrinoid deposits
Vessel wall necrosis (especially in the kidney)
Hyaline arteriolosclerosis causes what kidney appearance?
Cortical scarring
Shrunken kidney with granular surface
Thinned cortex
Hyperplastic arteriolosclerosis causes what kidney appearance?
Numerous petechial hemorrhages
What does arteriosclerosis mean?
Hardening of the arteries
Arterial wall thickening
Loss of elasticity
What are the three types of arteriosclerosis?
1) Arteriolosclerosis
2) Atherosclerosis
3) Monckeberg medial sclerosis
What are the two types of arteriolosclerosis?
Hyaline
Hyperplastic
In what vessels does arteriolosclerosis occur?
Small arteries and arterioles
What are complications of arteriolosclerosis?
Downstream ischemic injury
What happens in atherosclerosis?
Atheromatous plaque formation
What are complications with atherosclerosis?
Stenosis/occlusion Plaque rupture Aneurysm Thrombus Atheroembolism Microemboli
What is Monckeberg medial sclerosis?
Calcification of muscular arteries and internal elastic membrane
What type of arteriosclerosis is an age related degenerative process?
Monckeberg medial sclerosis
What is the number one cause of death in the US?
Myocardial infarction
What are the nonmodifiable risk factors for aterosclerosis?
Genetic abnormalities
Family history
Increasing age
Male gender
What is the genetic inheritance for atherosclerosis?
Multifactoral inheritance (AD= familial hypercholesteremia)
At what age is atherosclerosis most common?
40-60s
Increasing age= increasing risk
What is a protective effect for atherosclerosis?
Premenopausal estrogenized women (only younger women)
What is the most important factors for developing atherosclerosis?
Genetic predisposition
Are risk factors for atherosclerosis synergistic or additive?
Synergistic
What are modifiable risk factors for atherosclerosis?
Hyperlipidemia Hypertension Cigarette smoking Diabetes Metabolic syndrome Inflammation Hyperhomocysteinemia Lipoprotein a Factors affecting homeostasis Lack of exercise Competitive, stressful lifestyle Obesity
Which cholesterol delivers cholesterol to peripheral tissues?
LDL
Which cholesterol mobilizes cholesterol from the periphery?
HDL
How do statins work?
Inhibit HMG-CoA reductase (enzyme key in producing LDL cholesterol)
Decreases LDL, increases HDL
How can HDL be increased?
Exercise
Moderate alcohol intake
What decreased HDL?
Smoking
Obesity
What increases LDL?
Animal products Trans fat (fried, snack food)
What decreases LDL?
Soluble fiber
Statins
How do cigarettes promote atherosclerosis?
ROS and free radicals cause endothelial dysfunction and platelet activation through oxidization of LDL
How does diabetes promote atherosclerosis?
Sugar causes oxidative stress which damages blood vessels and increases inflammation
How does hyperhomocysteine increase aterosclerosis?
Oxidative stress leading to damage of the endothelium
C-reactive protein correlates with what?
Inflammatory activity
Cardiac risk
Pack per day for years doubles risk of what?
Ischemic heart disease
Diabetes doubles your chances of what?
Myocardial infarction
Hyperhomocysteinemia is associated with what?
Increased coronary atherosclerosis
Increased peripheral vascular disease
Increased stroke
What cytokine is associated with c-reactive protein?
IL-6
What makes up metabolic syndrome?
Abdominal obesity Increased triglycerides Low HDL Hypertension Insulin resistance
What is function of endothelium?
Non-reactive barrier that keeps blood and plasma going throughout the body smoothly in laminar flow
What causes endothelial activation?
Turbulent flow Hypertension Cytokines Complement Bacterial products Lipid products Advanced glycation end-products Hypoxia Acidosis Viruses Cigarette smoke
What happens in activated endothelium?
Increased expression of procoagulants
Adhesion molecules and proinflammatory factors
Altered expression of chemokines, cytokines, and growth factors
Activated endothelium is the key to driving the pathogenesis of what?
Atherosclerosis
What are the steps in vascular injury?
1) Recruitment of smooth muscle cells or smooth muscle precursor cells to intima
2) Smooth muscle cell mitosis
3) Elaboration of extracellular matrix
What are the two parts of an atherosclerotic plaque?
Fibrous cap
Necrotic center
What makes up the fibrous cap of an atherosclerotic plaque?
Smooth muscle cells Macrophages Foam cells Lymphocytes Collagen elastin Proteoglycans Neovascularization
What makes up the necrotic center of an atherosclerotic plaque?
Cell debris
Cholesterol crystals
Foam cells
Calcium
Where is fibrous cap located in the atherosclerotic plaque?
Adjacent to the lumen
What is the atherosclerotic plaque surrounded by?
Internal elastic lamina
What happens when vessels become completely occluded?
Neovascularization
What lipid is atheromatous plaques primary consisted of?
LDL (which accumulates in the intima)
When monocytes take up oxidized LDL what cytokine is released to recruit additional monocytes?
IL-1
Where does atherosclerosis typically occur?
Branch points
Posterior abdominal aorta
What are the steps for atherosclerosis?
1) Chronic endothelial injury
2) Endothelial dysfunction
3) Macrophage activation with smooth muscle recruitment
4) Engulfment of lipid with fatty streak deposition
5) Proliferation of smooth muscle with extracellular matrix deposition
Which growth factors are important for smooth muscle cell proliferation and extracellular matrix deposition?
PDGF
Fibroblast growth factor
TGF-alpha
What releases PDGF?
Platelets
Macrophages
Endothelial cells
Smooth muscle cells
What are the most extensively involved vessels with atherosclerosis?
Abdominal aorta
Coronary arteries
Internal carotid arteries
Circle of Willis
What is the earliest gross indication of atherosclerosis?
Superficial flat yellow fatty streaks
What are fatty streaks made of?
Lipid filled macrophages on the intimal surface
What does severe atherosclerosis look like grossly?
Ulcerated plaques with calcification and associated blood clots
What does a fatty streak turn into?
Fibrofatty plaque
What causes a fibrofatty plaque to turn into an advanced/vulnerable plaque?
Cell death/degeneration Inflammation Plaque growth Remodeling of plaque and wall extracellular matrix Organization of thrombus Calcification
What are the three clinical outcomes of atherosclerotic changes?
1) Aneurysm and rupture
2) Occlusion by thrombus
3) Progressive plaque growth
What causes aneurysm and rupture with atherosclerosis?
Mural thrombosis
Embolization
Wall weakening
What causes occlusion by thrombus with atherosclerosis?
Plaque rupture Plaque erosion Plaque hemorrhage Mural thrombosis Embolization
What causes critical stenosis with atherosclerosis?
Progressive plaque growth
What are clinical effects of atherosclerosis on the brain?
Thrombus causes infarction or stroke
Vascular rupture leas to intracerebral hemorrhage
What are clinical effects of atherosclerosis on the kidney?
Renal artery stenosis -> HTN
Ischemic injury with uremia
Renal failure
What is the principle cause of abdominal aortic aneurysms?
Atherosclerosis
Obstruction of visceral organs due to atherosclerosis causes what?
Chronic mesenteric ischemia nd infarction
Peripheral vascular disease causes what?
Claudication
Gangrene
Atherosclerosis can cause what in the heart?
Ischemic heart disease -> stenosis -> myocardial infarction
What is an excessive locational abnormal dilation of a blood vessel or ventricular wall?
Aneurysm
What is a “true” aneurysm?
Intact but thinned muscular wall at the site of dilation
What is a “false” aneurysm?
Defect though the wall of the vessel communicating with an extravascular hematoma that freely communicates with the intravascular space (pulsating hematoma)
What arises when blood enters a defect in the arterial wall and tunnels between layers?
Arterial dissection
Which aneurysm bulges out on one side?
Saccular
Which aneurysm bulges out on all sides of the vessel?
Fusiform
Where does a ventricular aneurysm occur?
Site of previous MI
What is cystic medial degeneration?
Normal elastin of the media is disrupted and replaced with areas of amorphous ground substance
What causes cystic medial degeneration?
Marfan
Ehlers Danlos
Systemic HTN
How does systemic HTN cause cystic medial degeneration?
Narrowing of small arterioles which feed the aorta leading to aortic ischemia, scarring, and inadequate ECM synthesis
What do vessels with cystic medial degeneration look like in Marfan syndrome?
Elastin fragmentation with areas without elastin fibers that are filled with proteoglycans
Marfan syndrome is caused by a mutation in what gene?
FBN1 (fibrillin gene)
What does the FBN1 or fibrillin gene do?
Needed for structural integrity of connective tissue
Is there increased or decreased TGF-beta in Marfan syndrome?
Increased
In Marfan syndrome fibirllin in unable to bind what?
TGF-beta
Increased TGF-beta activity weakens what?
Elastic tissue
What are symptoms of Marfan syndrome?
Tall stature Long fingers Subluxation/dislocation of lenses Pectus excavatum Mitral valve prolapse Aortic aneurysm Aortic dissection
Ehlers danlos is due to a mutation in what?
Collagen
What are symptoms of ehlers danlos?
Hyperelastic, fragile skin Joint hypermobility Lens subluxation Abnormal wound healing Widened scars Bruising Mitral valve prolapse Kyphscoliosis Rupture of colon, cornea, large arteries