hypertension Flashcards
mean arterial blood pressure is the
cardiac output vs the vascular resistance of the system
cardiac output is affected dby the
stroke volume times the heart rate
pre load
venous pressure that fills the heart after it empties, determined by volume status
after-load
resistance the heart has to pump against
contractility
how much force the heart contracts with
largest swings in blood pressure are due to
changes in systemic vascular resistance; increase in CO is rarely the cause of HTN
SVR is affected by
- local factors
- humoral factors
local factors that affect SVR
vasoconstrictors and vasodilators released by vascular smooth muscles and endothelial cells
humoral factors that affect SVR
AII and NE and prostaglandins
essential HTN
- 90% of HTN peeps have it
- idiopathic
- onset in 40s adn 50s
- genetic predisposition
secondary HTN
- diseased caused
- treating underlying cause can treat HTN
- dx: renal artery stenosis, primary hyperaldosteronism, pheochromocytoma
most common form of secondary HTN
chronic kidney disease
why does CKD cause HTN
- inability to alter Na handling after BP changes
- ineffective Na excretion
how do we sure HTN from CKD
decrease sodium intake and increase sodium excretion by using diuretics
HTN peeps have more AII in their system?
yep, this is demonstrated by the significant drop in blood pressure than in normal peeps when ACEi is administered
how renal artery stenosis causes HTN
- one kidney stenosis will affect the other due to the increase in RAAS products that will increase SVR and lead to an impaired natriuresis
- bilateral stenosis have a intolerance for ACEi
two types of renal artery stenosis
1- atherosclerotic
2- fibromuscular dysplasia
how does hyperaldosteronism cause HTN?
- Na retention and hypervolemia
-
will hyperaldosteronism have a high renin levels?
nope, low
treatment for hyperaldosteronism
K+ sparing diuretics
how the activation of the sympathetic nervous system lead to HTN/
- increased adrenergic tone leads to HTN due to:
1. increased vascular tone
2. Na retention due to renin release stimulation
3. contractility increased
clinical syndrome of activation of the sympathetic nervous system
palpitations, headaches and flushing
