7- Pathophysiology of HTN Flashcards
diagnosis of HTN
2 or more recordings taken in seate position at 2 or more office visits
THN
> 140/90
are white-coat hypertensives at risk?
actually yes- at a higher risk for some of the cardiovascular related events seen in overtly hypertensive patients
the risk for MI, stroke, and HF doubles with a ___ increase in systolic or _____- increase in diastolic
20 stytolic or 10 diastolic
T or F: aging is a risk factor for hypertension
90% risk of developing HTN in normal middle aged adults
after age 50, _____ decreases while ____ continues upward trend
diastolic decreases while systolic continues to increase
why? (aginf impars cardiac function = reduce diastolic, alters vascular function = increase systolic)
older individuals are more likely to have isolated systolic hypertension than both HTN, younger more likely isolated diastolic
where are arterial baroreceptors located?
carotid sinus
moemnt-to moement modulation of blood pressure
nerual reflexes
where are the cardiopulmonary receptos
atria and pulmonary arteries
what activates a baroreceptor?
distending pressure in teh carotid or atria
increased stretch genereates an action potential
receptors respond only to stretch: T or F
both the actual stretch and how the strech is changing with time
why aren’t baroreceptors involved in long-term maintenance of blood pressure
resetting after extended periods of activation
integrating site for baroreceptor information
nucleus of the solitary tract NTS in the medulla of brainstem
an increase in afferent activity in a negative feedback loop will reslut in…
reduction in efferent nerve traffic
a fall in arterial oxygen, icnrease in carbon dioxide or decrease in pH stimulates…
vasoconstriciton and bradycardia
ANG II causes…
direct vasoconstriction and moderate sodium reabsorption
and stimulataes aldosterone secretion –> even greater sodium reabsorption
“pressure naturesis”
high pressure, through an icnrease in resistance, will transiently increase sodium excretion. since water follows sodium, this also results in a reduction in blood volum. Blood pressure is therefore restored.
reduction in kidney mass, enhance reabsoption of sodiu,, or decrease in glomerular capillary filtration ( reduce filtration coefficient or increase preglomerular resistance) WILL –>
hypertension
underlying pathology of HTN is known
secondary HTN
because these are secondary forms of hypertension, the elevation of blood pressure is an apporpriate response to the intial stimulus
pathologoy includes derangemen tof the chemoreflex due to intermittent hypercapnic/hypoxic episodes
obstructive sleep apnea
increased sympathetic activity results which not only changes ventilation but also peripheral resistance
pheochromocytoma
NE/epi secreting tumor
why has pharmacological treatment of RVD been cotnroversial
ANG II constricts afferent and efferent arteriole to maintain a constant GFR and changing renal hemodyanamic may impair renal function
first line treatment for HTN
lifestyle modification
weight reduction
5-20 mmHG/10kg weight loss
DASH eating
8-14 mmHg
sodium restriction
2-8 mmHg reduction
physical activity
4-9 mmHg
moderate alcohol consumption
2-4 mmHg
resistant/refractory htn
blod pressure goal not reached with 3 or more pharmacological agents
first pharmacological agent, then other combinations
1= diruetic 2= RAAS target, calcium channel blocker or beta blocker
stage 1 HTN
140/90
stage 2 HTN
160/100
target BP for older than 60
150/90
target BP for under 60 yo
140/90
target BP for those with diabetes or chronic kidney disease
140/90
each incremental increase in SBP (20 mm) __________ risk for MI, HF, stroke, kidney disease
doubles
risk increases exponentially
most people have ______ HTN (95%)
essential/primary HTN
plaques, fibrosis in renal artery or arterioles causes the intrarenal baroreceptors to sense what?
a decrease in renal blood pressure which activates the cascade causing an increase in blood pressure = HTN
