Hypertension - Gosmanova Flashcards
What is the bp range in prehypertension?
120-139
80-89
What is the bp range in stage 1 hypertension?
140-159
90-99
What is the bp range in STage 2 htn?
> 160
> 100
What perecentage of htn is primary? when is its onset?
90%
40-50s
What percentage of htn is secondary? who gets it?
10%
less than 30 yo or greater than 50 yo
Does genetics play a factor in HTN?
yes, 70-80% have positive family history
What have the biggest effects on HTN?
stress and lifestyle
What is the formula for Mean Arterial Pressure?
CO X SVR
What does “hypertension follows the kidney” mean?
a normotensive person who receives a kidney transplant from someone with htn will develop htn. also the reverse is true, with htn pts getting good kidneys developing good bp
What is guyton’s theory of long-term bp control?
bp and sodium homeostasis are related through the mechanism of pressure natriuresis. When perfusion pressure increases, renal sodium output increases and ecf and bv contract by an amt sufficient to return arterial blood pressure to baseline
Explain pressure natriuresis.
Increase BP leads to decreased blood volume leads to decreased bp
changes in Na excretion in talh occur without decreased gfr
What is the difference in the effect of arterial pressure in a normal kidney vs abnormal in terms of na excretion?
a normal kidney only needs a slight change in arterial pressure to increase na excretion. an abnormal kidney requires a bigger change to cause increased na excretion (leaving the person with a chronic elevated bp)
What is the role of salt in htn?
a low sodium diet leads to no htn. htn is almost non-existent in rural populations wo much salt intake.
shows that htn is hugely diet based
not everyone who consumes a lot of salt develops htn. why?
those that do frequently have salt-sensitivity, increasing in bp on a high salt diet and decreasing bp with low salt diet.
what population has been deemed largely salt sensitive?
african americans
50% of htn individuals are salt sens
what is the mechanism of salt consumption that leads to htn?
decreases salt excretion leads to activation of sns. increases activity of kidney na/h exchanger, increasing intracellular ca2+ in vascular smooth muslces which decreases the NO levels, causing vasoconstriction (which is combined with increased ecfv becaues of salt levels)
What factors affect systemic vascular resistanec?
vasoconstrictors (angio II, norepinephrine, endothelin)
vasodilators: NO, prostacyclin, prostaglandins E and D
NO
How does RAAS lead to increased SVR?
Angio II causes vasoconstriction
Juxtaglomerular Cell Receptors
What does the B1-Rc do?
Adenosin2-Rc
Prostaglandin Rc:
activation of renin increases
Activation of decreased renin
Activation increases renin
Increased NaCl delivery to the macula densa triggers what?
Increased adenosine
Decreased delivery of macula densa cells does what?
incresaed NO and prostaglandins
Is renin elevated in everyone with HTN?
No, some people havec low PRA termed “wet htn”
Which population has renal artery stenosis more?
whitees
What are the most common causes of renal artery stenosis?
atherosclerosis fibromuscular dysplasia (many points of small narrowing along the artery)
What is cushing’s syndrome?
glucocorticoid excess which is similar in shape to aldosterone. so it triggers aldo receptors. then enzyme 11B-HSD2 is overwhelmed and can’t turn over all cortisol into cortisone. So cortisol stays activating aldosterone receptors.
what are the clinical features of pseudohyperaldosteronism?
HTN, hypokalemia, metabolic alkolosis, low renin and aldosterone
what is deficiency in pseudohyperaldosteronism?
11B-hydroxysteroid dehydrogenase, so you loss the abililty to turn cortisol into cortisone
what is liddle’s sydnrome?
another pseudohyperaldosteronism syndrome but with always active Na channels in distal tubule due to mutation in beta or gamma subunits
Increased Na reabsorption in CD will increase or decrease K secretion?
increase K secretion, to create favorable balance
What is metabolic alkalosis due to>
increased H secretion by h pump in response to activation of mineralocorticoid receptor
hypokalemia causes intracellular shift of h into tubular cells and secretion into lumen
what is gordon’s syndrome?
salt-sen hypertension, hyperkalemia and metabolic acidosis, aways activat thiazide-sensitive nacl channels in dct
