Exam IV: Hypertension & Vessel Diseases I Flashcards
Essential Hypertension
Also known as Primary Hypertension
95% of cases and idiopathic/unknown cause
Multifactorial: enetic polymorphisms and environmental factors
Usually does not cause short-term problems
If controlled: compatible with long life and asymptomatic
Mechanisms: Genetic factors Reduced renal sodium excretion Vasoconstrictive influences Environmental factors
Primary vs. Secondary Hypertension
Essential = Primary Hypertension: means that it is the initial presentation of any disease
Secondary: developed from a disease that the patient had first
Primary/Essential Hypertension
Primary 90-95% of patients
Environmental, Lifestyle, Genetic
No single gene identified, but substantial genetic component - 32-57%
Western diet lifestyle increases risk
Secondary Hypertension
Secondary = 2-5% of patients
Renovascular
Other Renal
Endocrine: endogenous or exogenous (OCP/oral contraceptive pill, 5% develop hypertension)
Renal Artery Stenosis- #1 cause
90% - Atherosclerotic in aorta blocks the renal arteries
Usually > 50 of age and smoke
10% Fibromuscular dysplasia- usually young women
Secondary Hypertension: Fibromuscular Dysplasia
Fibromuscular Dysplasia -tends to affect young women (20s and 30s)
Pathology
Intimal and medial layers affected (most common) with adventitial subtypes
Distal arterial segmental stenosis
String of beads sign – intimal thickening in certain areas and not in other areas causing the beads formation
Just change in vasculature
Secondary Hypertension: Endocrine
Hyper or hypothyroidism
Adrenal Adenoma/Hyperplasia:
- Aldosteronoma
- Cushings syndrome
- Pheochromocytoma
Primary disease in endocrine organs leading to secondary hypertension
Secondary Hypertension: Vascular
Coarctation of the aorta
Narrowing just distal to subclavian- causes damage to surface
Typically upper limb hypertension with lower extremity gradient
Occurs in Turner’s syndrome
Key clinical point- hypertension in upper extremities, but lower extremities are normal
Myocardial and Renal Effects of Hypertension
Myocardial– cardiac hypertrophy, ischemic injury because pushing against high pressure, compensation for overloading/high volume
Vascular and Renal:
- Hyaline arteriolosclerosis and arterial sclerosis (benign nephrosclerosis)
- Proliferative arteriolosclerosis (onion-skinning) and fibrinoid necrosis (malignant nephrosclerosis/hypertension)
Hypertensive Emergency(Malignant Hypertension)
Severe hypertension causing acute organ impairment
CNS, KIDNEY, HEART
Pathologically with more severe vessel damage, often thrombus (thrombotic microangiopathy) and fibrinoid necrosis of vessel wall
Since turbulence in vessels = clot formation
Fibrinoid necrosis of vessel wall = start to see a lot of problems like ischemia, thrombosis, etc.
Accelerated (Malignant) Hypertension
~5% of hypertensives
Rapidly rising blood pressure
Untreated: death within a year or two because continuous under perfusion of organs
Severe hypertension:
Systolic >200 mm Hg
Diastolic >120 mm Hg)
Renal failure
Retinal hemorrhages and exudates with or without papilledema
Superimposed on pre-existing benign hypertension
Malignant Hypertension: Kidneys and Thrombotic Microangiopathy
Flea – bitten kidney in malignant hypertension; petechial hemorrhages due to areas of fibrinoid necrosis of vessels
Thrombotic microangiopathy may be seen microscopically:
No more nice vessel wall- broken down
Clot formation in lumen
Hypertension in the Retina
Retina: narrowing of vessels causing hemorrhages within the eyes
Hypertension in the Brain
Intracerebral Hemorrhage
Mid to late life – peak in 60s
Rupture of small intraparenchymal vessel
Hypertension accounts for >50%
Charcot- Bouchard Microaneurysms- small aneurysms of small vessels usually in the basal ganglia
Just one vessel to cause a big hemorrhage
Bleeding in the brain- drill holes to release pressure and bleeding
Lacunar Infarcts: lake-like spaces (not more than 15 mm)
Hypertensive Encephalopathy
Hypertensive Encephalopathy: presentation of hypertensive emergency
Clinical pathologic entity: severe cerebral dysfunction and pathologic correlates of cerebral edema and fibrinoid necrosis of arterioles
Fibrinoid necrosis: deposition of Ab-Ag complexes in the vessel walls (antibody antigen complexes)
Regulation of Normal Blood Pressure
Blood pressure: function of cardiac output and peripheral vascular resistance
Influenced by multiple genetic, environmental, and demographic factors
Major factors that determine blood pressure variation:
BMI and diet = modifiable
Age and gender = cannot modify
Hypertension: Small Blood Vessel Disease
Hypertension: associated with 2 forms of small blood vessel disease
- Hyaline arteriolosclerosis
- Hyperplastic arteriolosclerosis
Hyaline Arteriolosclerosis
Morphology:
Homogeneous, pink hyaline thickening
Luminal narrowing
Generalized and severe in individuals with hypertension
Common feature of diabetic microangiopathy
Deposition of hyaline (pink stuff) with nice nuclei, but in fibrinoid necrosis you won’t see nice nuclei
Hyperplastic Arteriolosclerosis
Morphology:
“Onion-skin” lesions- concentric laminated thickening of walls and luminal narrowing
Smooth muscle cells and reduplicated basement membranes
Occurs in severe (malignant) hypertension (kidney)
“Onion-skin” lesion plus fibrinoid deposits
Vessel wall necrosis (necrotizing arteriolitis)
Aneurysm
Aneurysm: atherosclerotic plaque in intima layer pushes on media layer and starts to die because prevents blood and nutrients from getting through as well as the waste material from exiting
Causes necrosis of media/breakdown of media and wall gets weak and thin so bulges out
Most common in abdominal aorta
Classifications of Aneurysms
True – contains all layers of the vessel wall
False (pseudo) – contained rupture
Fusiform – circumferential and symmetric
Saccular – asymmetric bulging of a portion of the wall (one sided)
Dissection
Aortic Dissection
Intramural blood between inner 2/3 and outer 1/3 of aorta
Between the intima and media: because small break in intima and zipper stars to spread out
May or may not be associated with aortic dilation
Cystic Medial Degeneration
Pooling of mucosubstances, elastic fragmentation with disruption of elastic lamellar structure, fibrosis and loss of smooth muscle cell nuclei
Media degenerates and breaks down
Seen in Marfan’s syndrome
Aortic Aneurysm
Localized permanent pathologic dilatation of a vessel at least 50% >normal
What is normal?
Relates to age, location, body habitus and daily workload
Increase age = increase diameter
Ascending normal <3.0 cm
Complications of Aortic Dissection
- Rupture or tear of vessel and can get into the pericardium
- Within pericardium, only supposed to be 15mL fluid in there, but the blood leaking in causes blood all around the heart in the pericardium and will clot and cause cardiac temponade so heart cannot beat and stops beating
- Causing collapse of coronary arteries
Either way you cut it… not a good thing to have
Marfan’s Syndrome
Tend to see aortic dissections in Marfan’s syndrome because mucosubstance build up in the media layer
Fibrillin gene mutation causes breaks/disruptions in elastic bands (stars in photo A)
Mucopolysubstances – get intima damage/tears, separate and then aortic dissection
Peripheral Arterial Diseases
Large vessels: aorta; diseases include granulomatous disease with giant cell arteritis and Takayasu arteritis
Medium: branches off of aorta and arteries; diseases include immune complex mediated such as polyarteritis nodosa, and anti-endothelial cell Ab such as Kawasaki disease
Small: arterioles, capillaries, venules, and veins
Giant Cell (Temporal) Arteritis
Most common form of vasculitis among elderly individuals in the United States and Europe
Chronic, granulomatous inflammation of large to small-sized arteries:
Arteries in the head, temporal arteries, and vertebral and ophthalmic arteries
Nodular intimal thickening: see altering/skip lesions (makes bead formation) to reduce diameter and blood flow isn’t going where is needs to causing transient ischemic changes
Classic lesions: see granulomatous inflammation (giant cells), but if you don’t see this stain the elastic lamina and if fragmentation present then know it is temporal arteritis
Takayasu Arteritis
Also known as granulomatous vasculitis of medium and larger arteries
Ocular disturbances
Marked weakening of the pulses in the upper extremities AKA pulseless disease
Transmural fibrous thickening of the aorta
Severe luminal narrowing of the major branch vessels
Adventitial mononuclear infiltrates are perivascular, so cuffing of the vasa vasorum
Intense mononuclear inflammation in the media
Granulomatous inflammation: giant cells and patchy medial necrosis
Polyarteritis Nodosa
Systemic vasculitis of small or medium-sized muscular arteries
Not arterioles, capillaries, or venules
Involving renal and visceral vessels but sparing the pulmonary circulation, thus it DOES NOT AFFECT THE LUNGS
Microscopically: Areas of un-involved tissue aka has segmental involvement
Fibrinoid necrosis
Kawasaki Disease
Leading cause of acquired heart disease in children
Acute febrile, self-limited illness
Associated with an arteritis: affects large to medium-sized and small vessels
Predilection for coronary artery involvement
Pronounced inflammation affecting the entire thickness of the vessel wall
The child is ill or just recovered from an illness… have fever if ill
Microscopic Polyangiitis
Necrotizing vasculitis
Affects capillaries, arterioles and veins
AKA hypersensitivity vasculitis or leukocytoclastic vasculitis
Necrotizing glomerulonephritis and pulmonary capillaritis–particularly common
Segmental fibrinoid necrosis of the media with focal transmural necrotizing lesions
INVOLVEMENT OF THE LUNGS
Churg-Strauss Syndrome
AKA allergic granulomatosis and angiitis
Relatively rare
Small-vessel necrotizing vasculitis
Associations: asthma, allergic rhinitis, lung infiltrates, peripheral hypereosinophilia, extravascular necrotizing granulomas
Vascular lesions:
Similar to polyarteritis nodosa or microscopic polyangiitis
Accompanied by granulomas and eosinophils
Other clinical findings:
Palpable purpura
Gastrointestinal tract bleeding
Renal disease (focal and segmental glomerulosclerosis)
Wegener Granulomatosis
New name: Granulomatosis with polyangiitis
Necrotizing vasculitis: vessel walls fall apart and blood surround tissue and alveolar hemorrhage
Triad:
- Acute necrotizing granulomas of the URT or LRT or both
- Necrotizing or granulomatous vasculitis affects small to medium-sized vessels
- Renal disease: focal necrotizing, often crescentic, glomerulonephritis
Wegener Granulomatosis: Lesions
Lung lesions:
Granulomas with geographic patterns of central necrosis = caseous
Vasculitis
Alveolar hemorrhage
Renal lesions:
Focal and segmental necrotizing glomerulonephritis
Crescentic glomerulonephritis
Middle aged person without eosinophils = Wegener’s case
Intermittent coughing up blood
Thromboangiitis Obliterans
AKA Buerger’s disease
Almost exclusive to heavy cigarette smokers
Before the age of 35
Medium-sized and small arteries: tibial and radial arteries
Segmental and thrombosing
Acute and chronic inflammation
Luminal thrombosis: small microabscesses
Claudication symptoms or cramping in lower legs because reduction in lumen in lower extremities and the blood flow isn’t adequate
Sometimes patients must have amputation of fingers or legs
Raynaud Phenomenon
Exaggerated vasoconstriction of digital arteries and arterioles
Characteristic changes: digits show red, white, and blue color changes; most proximal to most distal
Secondary Raynaud Phenomenon
Secondary Raynaud phenomenon
Vascular insufficiency of the extremities secondary to arterial disease caused by other entities including:
SLE, scleroderma, Buerger disease, or atherosclerosis
