Hypertension Flashcards
– Primary HTN (essential)
cause is unknown (~90% of cases)
– Secondary HTN
has definable cause (less common)
Normal Blood pressure
SBP Less than 120
DBP less than 80
Pre HTN
SBP 120-139
DBP 80-89
Stage I HTN
SBP 140-159
DBP 90-99
Stage II HTN
SBP >160
DBP > 90
Hypertensive Crisis
SBP >180
DBP>110
B2 receptors on PVR
Decreases
Local regulators: Nitrous oxide on PVR
Decreases
Local regulators: Adenosine on PVR
Decreases
Local regulators: Prostaglandins on PVR
Decreases
No matter how high the C.O. or TPR,
renal excretion has capacity to completely return BP to normal via reducing intravascular volume
Pressure natriuresis:
normal kidney response to INCREASING BP = INCREASING urine volume and Na+ excretion
This is blunted in hypertensive pts:
– Microvascular and tubulointerstitial injury in kidney secondary to HTN impairs Na+ secretion
Baroreceptor Reflex:
Changes in BP detected by stretch receptors (baroreceptors), located in large arteries above heart
– aortic arch
– aortic sinuses (behind aortic valve cusps)
– carotid sinus (base of each internal carotid artery)
Essential HTN \_\_\_\_\_\_\_of cases, exact cause \_\_\_\_\_\_ • Dx’d after \_\_\_\_\_\_\_\_\_\_ • Thought to result from \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_with environmental stressors. • The defects may be \_\_\_\_\_\_\_\_\_\_\_\_
90% of cases, exact cause unknown.
• Dx’d after rule out Secondary HTN.
• Thought to result from multiple defects in pressure
regulation that interact with environmental
stressors.
• The defects may be acquired or genetic.
HTN Abnormalities
Heart, Blood Vessels & Kidney
Also contribute to development HTN.
HTN and heart
HEART
– Increased C.O. – HTN pts. have excessive sympathetic response under psychologically stressful conditions.
HTN and Blood Vessels
Increase TPR secondary to to Increase sympathetic activity
– abnormal tone secondary to local factors (ex. endothelin)
– ion channel defects in smooth muscle
KIDNEY causes (FII)
causes volume based HTN via excess Na+ & H20 retention:
- fails to regulate renal blood flow
- ion channel defects that increase Na+ retention
– inappropriate renin excretion
(Renin secretion should be suppressed by high blood pressure, so even “normal” levels are inappropriate in HTN pts.
ESSENTIAL HTN : Other genetic factors (IOM)
Other genetically linked factors:
– Insulin resistance/DM
– Obesity
– Metabolic Syndrome
**Obesity directly assoc’d. with HTN:
– Increased body mass = Increased blood volume
– Adipocytes release angiotensinogen
– Adipocytes release profibrinogen & plasminogen
activator inhibitor = Increase Viscosity
Essential HTN and Metabolic syndrome (GHID)
Metabolic Syndrome:
• Increase atherogenic risk factors including HTN
• hypertiglyceridemia
• DECREASE HDL
• glucose intolerance and truncal obesity
Vascular resistance increases with age due to
medial hypertrophy as vessels adapt to prolonged pressure stress.
Essential HTN comprised ____% of patients
age of onset
Family hx of ____
Labs:
90% age of onset 20-50 Family hx of HTN Increase Cr Decrease K
What are the 2nd causes of HTN (CPP RCC)
Chronic renal disease Rrimary aldosteronism Renovascular Pheochromocytoma Coarctation of Aorta Cushing Syndrome
HTN carries increased risk of
post MI complication ex. ventricular wall rupture
Secondary Hypertension Has\_\_\_\_\_ may required \_\_\_\_\_\_ Often \_\_\_\_ if untreated \_\_\_\_\_
- Has defined structural or hormone cause.
- May require different therapy from EH.
- Often curable.
- If untreated, adaptive changes lead to EH.
In general, causes for Secondary HTN can be: (MERE)
– Mechanical
–Exogenous
–Renal
– Endocrine
EXOGENOUS CAUSES
Meds: – Oral contraceptives increased renin secretion. – Estrogen Increased hepatic angiotensinogen production. – Glucocorticoids – Cyclosporine – Erythropoietin – Sympathomimetic drugs – (NSAIDs via Na+ and water retention)
Renal parenchymal ds:Damaged nephrons
damaged nephrons cant excrete normal amounts of Na & water = Increase vol & C.O. = HTN
Renal parenchymal ds:Renal Artery stenosis
• Renal artery stenosis: one or both arteries lead to HTN
– Main Cause: Atherosclerosis
– Other Causes: emboli, vasculitis, external compression of renal artery
Renal parenchymal ds: Low perfusion pressure
= Increased Renin secretion
For unitlateral Artery disease
ACEI, contraindicated in bilateral renal stenosis
Avoid for Bilateral renal artery ds. –
inhib. of ANGIOGENSIN II production may excessively reduce intraglomerular pressure & filtration, and worsen renal function in pts with bilateral ds. who already have compromised perfusion to both kidneys.
Coartaction of Aorta (sometimes involves
L. subclav. = decrease Left arm pressures
What are the two mechanisms of COA
• 2 mechanisms:
– 1- reduced blood flow to kidneys stims. Renin.
– 2- high press prox to coarctation stiffens aortic arch thru
medial hyperplasia and accelerated atherosclerosis, blunting baroreceptor response to high pressures.
SIgns of COA (MICW)
– Mid-systolic murmur
- Inadequate flow to legs or left arm.
– Claudication or fatigue.
– Weak/Absent femoral pulses.
What are the ENDOCRINE CAUSES Of HTN
GMTP
ENDOCRINE CAUSES – Pheochromocytoma – Mineralocorticoid – Glucocorticoid – Thyroid
Pheochromocytoma -
Adrenal medulla epi/norepi intermittent or chronic vasoconstriction, tachycardia & other SNS effects.
Signs and symptoms of Pheochromocytoma
PPTS
Severe throbbing HA
Profuse sweating
Palpitations
Tachycardia.
Diagnosis of Pheochromocytoma
Increases serum or urine catecholamine levels & their metabolites (vanillylmandelic acid and metanephrine)
Tx of Pheochromocytma
α-blocker phenoxybenzamine with β-blocker &
catecholamine biosynthesis inhibitor α-methyltyrosine,
Surgical resection
Secondary HTN endocrine causes of HTN Mineralocorticoid
ALdosterone
Primary aldosterone due to
From adrenal adenoma
Dx; obtain K level, urine, plasma renin and aldosterone
Tx: remove tumor
Secondary Aldosteronism -
from abnormally high ANGIOTENSIN II,
NO PROBLEM With Adrenal gland
3 causes of Secondary Aldosteronism RIO
– 1) rare renin-secreting tumor.
– 2) oral contaceptives - stim.s Liver to Increase angiotensinogen.
– 3) impaired ANGIOTENSIN II degradation in chronic liver ds.
Glucocorticoid-remediable Aldosteronism (GRA)
–
genetic rearrangement results in aldosterone synthesis
abnormally regulated by ACTH.
Hypertensive Crisis
Medical Emergency pressures >180/>110.
• Often caused by
Hypertensive crisis causes
acute hemodynamic insult superimposed on chronic HTN. (ex acute renal ds)
Glucocorticoids Dx
24 hours urine cortisol or DEXAMETHASONE
In Hypertensive crisis there is
• Severe pressure elevation = Increased ICP, hypertensive
encephalopathy (HA, blurred vision, confusion, somnolence, coma).
Hypertensive Crisis and eye
Retinal hemorrhages,exudates, papilledema seen
on fundoscopy
Hypertensive crisis tx
Tx: – nitroprusside (use with caution, can Increase ICP) – labetalol – fenoldopam – nicardipine
Optic disk edema is ______means _____
PAPILLEDEMA; Increased ICP
Tx of HTN: Diuretics classes are
Thiazides
Potassium Sparing diuretics
LOOP diuretics
Physiological Action of diuretics
Decreased Circulating Volume
Sympatholytics classes are :
B blockers
Combined alpha and beta blockers
Central Alpha 2 agonists
Peripheral alpha 1 antagonists.
Physiologic actions of sympatholytics
Decrease HR, contractility and renin secretion
Vascular smooth muscle relaxation
Decrease sympathetic tone
Vasodilators classes are
CCB Direct vasodilators (hydralazine)
PHysiologic actions of both CCB and direct vasodilators
Decrease PVR
Renin Angiotensin Aldosterone System angatonists ared
ACEIs
ARBs
Direct Renin Inhibitors
Physiologic actions of RAAS antagonists
Decrease PVR
Decrease sodium retention
Disease of Aorta subject to injury from________
mechanical trauma.
AORTA is continuously exposed to
high pulsatile pressure and shear stress.
IN AORTA• Elastin to collagen ration is _____And it _______
2:1 - allows expansion & recoil
In AORTA With age,
elastin degenerates, collagen becomes prominent = stiffening = Increases systolic press.
Diseases of the aorta appear as:
- Aneurysm
* Dissection
Aneurysm is an
• abnormal localized dilation
In aneurysm diameter
• diameter increase of at least 50%
What is a “True aneurysm” =
• manifest as _____and ____
dilatation of all three wall layers
fusiform or saccular
False aneurysm AKA_______There is
Pseudoaneurysm
Hematoma contained by adventitia or PERIVASCULAR CLOT
In false aneurysm there a
hole in media and intima
Which one is more common fusiform or saccular? what is FUSIFORM
Fusiform
Symmetrical dilation of entire circumference of a segment
Saccular is a
localized outpouching involving on a portion of the circumference
Pseudoaneurysm “False aneurysm” =
Contained rupture of wall
blood leaks out of vessel through hole in intima and
media, but contained by adventitia or perivascular thrombus.
Pseudoaneurysm warning
Very unstable, prone to complete rupture
True aneurysm causes
Ascending thoracic aortic aneurysms
TRUE ANEURYSM Also develops in certain genetic connective tissue disorders:
–MLE
Marfan syndrome
– Loeys-Dietz syndrome
– Ehlers Danlos syndrome (type IV)
Descending thoracic & abdominal aortic
aneurysms
Assoc’d. with atherosclerosis.
Inflammation
INCREASED CRP and IL-6
Thoracic aneurysms may compress
– Trachea or Mainstem bronchus =
= hoarseness
adjacent structures:
TRACHEA or MAINSTEM BRONCHUS
cough, dyspnea, pneumonia
If Thoracic aneurysms compress– Esophagus =
dysphagia
If Thoracic aneurysms compress– Recurrent laryngeal nerve
HOARSENESS
AORTIC DISSECTION is
- Tear in intima allows blood into medial layer.
* Blood propagates along the plane of the muscle layer.
AORTIC DISSECTION classifified as
CLASS A and CLASS B
Type A is more
Devastating because potential extension into coronary arteries and arch vessels, support structures of aortic valve or pericardial
space.
Clinical presentation of Type A
Pain travels_________can radiate anywhere in _____ or _____
Sudden severe pain with “tearing” or “ripping” in anterior chest (usually Type A) or between scapula (Type B).
– Pain travels along propagation, can radiate anywhere in
thorax or abdomen.
– (Painless dissection is possible but uncommon)
Tearing or ripping in anterior chest is usually type
A
Tearing or ripping in SCAPULA
B
Complications of Aortic Dissection : RUPTURE
Pericardial tamponade
Hemomediastinum
Hemothorax (usually left side)
Complications of Aortic Dissection : OCCLUSION or AROTIC BRANCH VESSELS (CCRIS)
Carotid (stroke) Coronary (MI) Renal (ARF) Iliac, Brachiocephalic, Subclavian (limb ischemia) Splanchnic (visceral infection)
Complications of Aortic Dissection: DISTORTION OF AORTIC ANNULUS
Aortic Regurgitation
Diseases of Aorta: Immediate DX necessary with
Contrast CT (CTA) TEE
Diseases of Aorta main goals for treatment
TX:
– Arrest progression of dissecting channel
– decrease systolic BP
– Decrease contractility to minimize wall shear
Causes of PAD (VAT)
Causes:
– Vasculitis
– Atherosclerosis (most common)
– Thromboembolism
Clinical presentation of PAD
Claudication, relieved by rest.
Evaluation of PAD ABI
ABI (ankle-brachial index)
– ABI > 1.0
normal
– ABI < 0.9
diagnostic of PAD
– ABI < 0.5
severe
3 measures to evaluate PAD
ABI
Segmental pressures
PVR (pulse volume recordings)
Treatment of PAD: ASA
antiplatelet therapy
Treatment of PAD: Cilostazol
Phosphodiesterase inhibitor (increase cAMP for vasodilation; antiplatelet effect)
Most dangerous aneurysm is
False aneurysms
Treatment of PAD: Pentoxifylline
INCREASED RBC deformability, improves claudication
PAD surgery
Surgical revascularization if medical therapy fails, or as first
line in severe limb ischemia
Causes of Acute Arterial Occlusion
– Thrombus
– Embolism
For acute arterial occlusion
Origin of arterial emboli most often the heart.
Rarely from venous, unless passing through abnormal intracardiac shunt (ex. ASD) = “paradoxical embolism”
Signs of PAD , 5 Ps
Tx
Signs/symptoms: "five Ps" – Pain – Pallor – Paralysis – Paresthesia – Pulselessness – Poikilothermia (coolness)
Anticoagulants: heparin
PAD : VASCULITIS SYNDROMES are (GTT)
– Takayasu arteritis
– Giant cell arteritis (Temporal arteritis)
– Thromboangitis obliterans (Buerger disease)
Takayasu Arteritis most commonly affected is
Aorta and its branches
Giant Cell ARTERITIS most commonly affected ______-as well as_________
Medium to Large vessels (especially cranial vessels) as well as aortic arch and branches
Thromboangiitis obliterans ( Buerger disease) most commonly affected
small size (especially distal arteries and extremities)
PAD : VASOSPASM:
RAYNAUD PHENOMENON
What is raynaud phenomenon?
• Extreme vasospasm of digits in response to cold
temperatures
Raynaud phenomenon when there is Temporarily inhibits blood flow =
painful transient ischemia
• Triphasic color response in digits in RAYNAUD’s
blanch (white) Phase I
– cyanosis (blue) - PHase II
– erythema (red- PHASE III
Most aneurysm occurs in
Ascending Aorta TYPE A
Venous diseases appear as:
- Varicose Veins (1o & 2o)
* Venous Thrombus (DVT & PE)
Varicose veins are
dilated, tortuous superficial vessels
Primary Varicose veins originate in the
superficial system
Causes of Varicose veins
– pregnancy
– prolonged standing
– obesity
SECONDARY varicose veins
Varicose veins occur when an abnormality in the Deep system causes superficial varicosities.
• Venous Thrombus “Thrombophlebitis”
• Superfical or Deep thrombus
Most common site of DVT
– femoral
– iliac
– calves
– popliteal
PE
• Often fatal.
• when clot embolism travels to lung.
PE: occurrence
600,000 per year in U.S.
PE and gas exchanged•
Gas exchange is impaired = V/Q mismatch.
PE patho
• Increase pulmonary vasc. resistance = elevation RV wall stress,
dilation and failure.
Virchow’s Triad are
Factors that predispose to Venous thrombosis
The triad of Virchow’s is (VHS)
a. Stasis of blood flow
b. Hypercoagulable state
c. Vascular diseas
Virchow’s Triad STASIS of BLOOD FLOW (PIHH)
Prolonged inactivity
Immobilized extremity
Heart failure
Hyperviscosity syndrome
Prolonged inactivity examples
surgery, prolonged travel
Immobilized extremity examples
Following bone fracture
Heart failure in stasis of blood flow
Systemic venous congestions
Examples of hyperviscosity syndromE
Polycythemia Vera
Hypercoagulable state Disease (FPANPMS)
Factor V leiden deficienty Prothrombin gene mutation Antithrombin, Protein C and S deficiency Neoplastic disease(lung breast CA) Pregnancy Myeloproliferative disease Smoking
Vascular damage examples
Instrumentation ( IV catheters)
Trauma
Clinical Presentation of DVT (ALULETH)
Asymptomatic in some pts. • Leg pain • Unilateral leg swelling • localized warmth • Erythema • Tenderness over phlebitic vein • +Homans' sign (nonspecific)
Clinical presentation of PE: (DPHSCTB)
dyspnea • pleuritic chest pain • hemoptysis • cough • syncope • tachypnea • bronchospasm
SUPERFICIAL THROMBOPHLEBITIS
What is it?
Sometimes a complication of _______
Does it lead to PE?
inflammation & thrombus superficial vein.
• sometimes a complication of in-dwelling intravenous catheter.
• does not lead to PE.
Tx of venous disease intervention
Wear compression stockings
Elevate Legs
Tx of PAD interventions (CAW)
Control smoking
Wear insulated gloves
Avoid cold environments
Ischemic ulcers characteristics (PWD)
- “punched out” appearance
- well defined edges
- Deeper wound base
Venous insufficiency Characteristics (SLMR)
Less defined edge
Shallow wound base
More proximal, medial on leg
Reddish-brown hemosiderin deposits.
Not so obvious signs of PAD
Loss of pulses distal to stenosis
– Bruits may be audible over sites of stenosis
Treatment of AORTA diseases
– based on___________
– Surgical repair while pt. maintained_________
– Aneurysm resected and replaced with prosthetic Dacron
graft.
size & pts. overall condition
on cardiopulmonary bypass.
Medical therapy of AORTA DISEASES
– β-blockers (reduce expansion rate)
– smoking cessation
Other symptoms of AORTA disease Clinical Presentation: • Most aneurysms \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ some patients feel \_\_\_\_\_\_\_\_\_ • Can cause \_\_\_\_\_\_\_ \_\_\_\_\_\_
• Most aneurysms asymptomatic.
• Some pts. with AAA feel pulsatile mass.
• Can cause abdominal/back pain or vague GI
symptoms.
Infection that can cause disease of Aorta (SSS TSF)
Infections: – Salmonella – Staph – Strep – TB – Syphilis – Fungi
**Ascending thoracic aortic aneurysms
Characterized by cystic
• Assoc’d. with _____ and ____
medial degeneration (“cystic medial necrosis”) = degeneration/fragmentation of elastic fibers in
medial layer.
aging and HTN.
Ascending thoracic aortic aneurysm may_____Causing______ and _________
May dilate aortic ring = aortic regurg. & symptoms of CHF
Caused by 3 categories of processes–> PAD
1.Structural wall changes secondary to degenerative conditions, infection, inflammation – lead to: • Dilation • Aneurysm • Dissection / Rupture
- Stenosis of lumen secondary to atherosclerosis, thrombus or inflammation.
- Spasm of vascular smooth muscle.
Non-pharmacologic of Treatment of HTN
• Wgt. reduction, exercise, diet, sodium restriction,
cessation alcohol & tobacco (relaxation therapy)
Renal causes: Secondary HTN
Renal artery stenosis is
Main cause _______
Other causes : –> EVE
• Renal artery stenosis: one or both arteries lead to HTN
– Main Cause: Atherosclerosis
– Other Causes: emboli, vasculitis, external compression of renal artery
***2nd HTN: Hx recurrent UTI - could =
chronic pyelonephritis = renal damage = HTN
***2nd HTN: excessive wgt loss
could = pheochromocytoma = excess SNS stim = HTN
***2nd HTN:– excessive wgt gain
could = cushing syndrome = excess glucocorts/aldost. = HTN
***Secondary HTN (compared to HTN) Age : \_\_\_\_\_\_\_ Severity: Onset Associated S/S
Age - if HTN develops age <20 or >50
• Severity - pressure rises dramatically vs. Essential Hypertension mild to moderate
• Onset - presents abruptly in previous normotensive
vs. gradual over yrs in EH
• Assoc’d signs/symptoms - renal artery bruit heard
on abd. exam in pt w/ renal a. stenosis
HTN: organ damage
HAAFE
Heart wall stress Aorta damage (increase risk aneurysm) Arterial damage, accelerated atherosclerosis via smooth muscle hypertrophy, Fatigued elastic fibers Endothelial cell dysfunction and
HTN organ damage : thrombosis
Increase risk of thrombosis and embolism damage target
organs
How does Pressure natriuresis work ?
increasing renal sodium excretion when incoming arterial pressure to the kidneys rises.
Signals sent to Medulla Oblongata: when BP high
– Increase BP causes rate of signals to rise, inhibits vasomotor center, DECREASES sympathetic tone, vasodilation causes BP to decrease
Signals sent to Medulla Oblongata: when BP LOW
BP causes rate of signals to drop, excites vasomotor center, INCREASE sympathetic tone, vasoconstriction and BP INCREASES
Hematocrit on BP
Increase
NP on BP
decreases
Aldosterone on BP
Increase
{H+} concentration on BP
Decrease
Which organ has the most potential control over BP
Kidneys
Insulin resistance/ DM
HTN patients with obesity or type II diabetes have increase glucose –> Increase insulin results in increase sympathetic activation, contributes to HTN
Increase insulin also stimulates what?
Vasoconstriction smooth muscle hypertrophy = Increase vascular resistance
Smooth muscle hypertrophy also caused by
direct mitogenic effect of insulin or Increase sensitivity to PDGF