Hypertension and Vascular Flashcards
Whats the equation for MAP?
MAP = SVR x CO
How is blood pressure controlled? (3)
- autonomic nervous system
- renin-angiotension-aldosterone system
- renal changes
how does the autonomic nervous system control arterial blood pressure?
ANS controls arterial blood pressure by:
- brainstem centrally
- baroreceptors in the carotid sinus peripherally
in a HYPERtensive state, how will the baroreceptors in the aortic arch and carotid sinus affect vagal tone and sympathetic tone?
- increase vagal tone
- decrease sympathetic tone
- to decrease HR and vasodilate
in a HYPOtensive state, how will baroreceptors in the aortic arch and carotid sinus affect vagal and sympathetic tone?
- decrease vagal tone
- increase sympathetic tone
- to increase HR, vasoconstriction, and increase contractility
what will activate the renin-angiotensin-aldosterone system?
- hypotension
- decreased sympathetic tone
what will the renin-angiotensin-aldosterone system result in?
- increased vasopressin
- increased angiotensin II
what will angiotensin II do to act as a vasoconstrictor?
ATII stimulates aldosterone production, leading to sodium and water reabsorption by the kidneys
what can the renal system do to manipulate arterial blood pressure?
control total body sodium and water
what is hypertension?
elevation of arterial BP
what can hypertension lead to if uncontrolled?
MI, CVA, renal failure and death
goals for hypertensive therapy?
what is essential HTN (or primary HTN)?
the most common form of hypertension (>90%), not secondary to an underlying cause
what are risk factors for developing hypertension?
- age
- family history
- obesity
- insulin resistance
- diet and lifestyle
what is secondary hypertension?
- less than 10% of all causes of HTN
- secondary to another cause, often either a renal or endocrine disorders
what renal disorders can lead to secondary hypertension?
- fibromuscular dysplasia
- renal artery stenosis
what endocrine disorders can lead to secondary hypertension?
- pheochromocytoma
- cushing’s syndrome
- hyperaldosteronism
- hyperthyroidism
other than renal and endocrine disorders, what can cause secondary hypertension?
- meds
- neuro disorders
- scleroderma
what organs autoregulate blood flow?
- brain
- heart
- kidneys
what does it mean for an organ to autoregulate blood flow?
the organ can maintain constant blood flow with changing perfusion pressures
chronic hypertension can lead to microvascular changes resulting in what?
ischemic strokes
the majority of CVAs occur due to what etiology?
ischemia
what can occur as the vasculature becomes less compliant?
causing LVH
- > diastolic dysfunction
- > angina/MI
- > heart failure
what can HTN do to the kidneys?
causing glomerulal damage
- -> albuminuria (protein lost in the urine due to impaired kidney function)
- -> overt renal failure
What are normal creatinine levels?
men 0.8-1.3
women 0.6-1.0
HTN emergencies imply what?
acute end organ damage
what are some examples of HTN emergencies?
- CVA
- encephalopathy
- LV failure
- MI
- aortic dissection
- renal failure
what is HTN urgency imply?
high blood pressure without signs of end organ damage
HTN emergency should be attenuated by…
IV anti-hypertensives
BP should be lowered by 20% within 4-6 hours and then gradually normalized over a few days
HTN ugency can be attenuated by…
PO medications
what should be used for HTN PTs with chronic kidney disease (CKD)?
- ACE inhibitor
or - ARB
what can be used for general population in treating HTN?
- thiazide diuretic
- ACE inhibitor or ARB
- calcium channel blocker
- black people NO ACE inhibitors or ARB
how do thiazide diuretics work?
- HCTZ (hydrochlorothiazide) acts to reduce sodium reabsorption in the distal convuluted tubule, causing water loss
how do loop diuretics work?
loop diuretics inhibit sodium and chloride reabsorption in the loop of henle leading to water loss, increasing prostaglandin levels.
what are two loop diuretics?
furosemide
torsemide
name two ACE inhibitors
lisinopril
enalapril
what will ACE inhibitors cause?
- vasodilation
- vascular smooth muscle relaxation
- natriuresis
- decreased vasopressin release
what are ARBs? Name two.
angiotensin receptor blockers
- losartan
- valsartan
what do ARBs cause?
block the AGII receptor causing:
- vasodilation
- vascular smooth muscle relaxation
- natriuresis
- decreased vasopressin release
what is natriuresis?
the process of secreting sodium by the kidneys
name two CCBs (calcium channel blockers)
amlodipine
nicardipine
what do CCBs cause?
decreased intracellular Ca2+ causing
- vasodilation
- negative inotropy
- negative chronotropy
- reduced aldosterone production
name the 3 kinds of B receptors
- B1 - heart, kidneys
- B2 - muscle
- B3 - adipose tissue
what do B blockers cause?
- negative chronotropy
- negative inotropy
- antiarrhythmic
- reduced aldosterone production
- smooth muscle relaxation
would you use B-blockers first for HTN treatment?
NO!
what are the three layers of the aorta?
- intima
- media
- adventilla
whats an aneurysm of the aorta?
a dilation of the aorta
whats the difference between a true and pseudoaneurysm?
pseudoaneurysm does not involve all 3 layers of aortic tissue
what is the possible etiology of an aortic aneurysm?
- HTN
- Atherosclerosis
- collagen vascular disease
- bicuspid aortic valve
- syphilis
- HLD
- mycotic
- inflammatory
whats an aortic dissection?
intimal tear creating a false lumen for blood to enter.
What is the DeBakey classification for aortic dissections?
I - originating in ascending aorta and extends to aortic arch or further
II - originates and confined to ascending aorta
III - originates in descending aorta
what is the Stanford classification for aortic dissections?
A - any dissection involving the ascending aorta regardless of origin
B - all other dissections of the aorta
what is the possible etiology for aortic dissection?
- HTN
- collagen vascular disease
- bicuspid aortic valve
- inflammatory
- trauma
- complication from heart surgery
what does carotid artery stenosis primarily involve?
the internal carotid arteries, due to atherosclerotic disease
intervention is needed in what % of carotid stenosis cases?
> 70%
What does TIA stand for?
transient ischemic attack
what are risk factors for CAD?
- HTN
- HLD
- DM
- PAD
- tobacco use
what surgeries can be done for carotid artery disease?
- stenting
- endarterectomy
what do the carotid bodies do?
act as chemoreceptors to maintain homeostasis during hypoxia.
damage could lead to blunted hypoxic drive and labile BP
what do you do if there is a hematoma?
- call for help
- get a scalpel
- open the neck
- hope surgery gets there fast
what is raynaud’s?
vasoconstriction of the extremeties during cold or stress
- mostly seen in females
- may reduce peripheral extremety blood flow
- maybe related to connective tissue disorders
where does deep vein thrombosis (DVT) usually occur?
lower extremities
how do you treat DVT?
anticoagulation and maybe a IVC filter (inferior vena cava)
what might need to be done for a pulmonary embolism (PE)?
emergency embolectomy
what can lead to a thrombus/embolus developing?
- vessel wall injury
- hypercoagulability
- stasis (inactivity)
