Unit 4 - Hypertensives Flashcards
(47 cards)
what are causes of secondary HTN?
- renal
- chronic kidney disease (high volume, high renin)
- renal artery stenosis - drugs
- ETOH, OCP, and NSAIDs are most common
- appetite duppressants
- TCA, MAOi - endocrine
- pheochromocytoma (uncommon)
- Cushing’s disease
- hyperaldosteronism
- hypo/hyperthyroidism
- hyperparathyroidism - pulmonary
- obstructive sleep apnea
usually HTN decreases if treat the underlying cause
what are BP factors that aren’t modifiable?
- genetics (FH of vascular disease in men >50 or women >60)
- race (African-Americans have higher)
- gender (females)
- age
what are BP factors that are modifiable?
- Na+ intake (largest controllable variable)
- obesity, sedentary
- heavy ETOH
- meds
- physiologic stress
- diets low in K+ and Ca++
where does end-organ disease occur? in who is it most common?
related to extent of BP elevation and duration of HTN; higher in African-Americans and premenopausal women
- brain (stroke, small vessel disease)
- eyes (retina)
- vascular tree (vascular stiffness, atherosclerosis, aneurysm)
- heart (coronary artery disease, LV hypertrophy)
- kidneys (nephrosclerosis)
what is the most important, and earliest manifestation of end-organ disease?
LV hypertrophy
when is secondary prevention more beneficial?
before end-organ damage sets in
- if only essential HTN w/o damage, then can take slow approach to decreasing HTN
- if has many end-organ damage (or even just LV hypertrophy), then must take very swift action
in a black VS white patient, what is their essential HTN most likely caused by?
black: increased peripheral vascular resistance
white: higher renin
how come most people don’t faint when standing up?
catecholamines are released to vasoconstrict and cause tachycardia
-thus the dip in BP is less, and one can compensate once upright
what is the most potent vasoconstrictor and what does it act on?
angiotensin II
-acts on small afferent arteriole and larger arteries/veins
what is the basic mech for diuretics?
decrease intravascular volume
-initial decrease in BP and CO, but over time CO returns to normal
what is the basic mech for angiotensin blockers?
inhibit production/action of AII (vasoconstrictor) to decrease peripheral vascular resistance
what is the basic mech for direct vasodilators?
relax vascular smooth muscles, and thereby reduce peripheral vascular resistance
what is the basic mech for sympathoplegic agents?
decrease peripheral vascular resistance by decreasing sympathetic tone (beta-blockers, alpha-blockers, and central/peripheral sympathetic blockers)
what is the main effect of diuretics?
plasma volume decreases
- decreased peripheral resistance
- increased renin (due to decreased renal perfusion)
what is the main effect of central acting sympatholytics and adrenergic blockers?
decreased sympathetic system causes decreased CO and TPR
-increased renin (due to decreased CO causing decreased renal perfusion)
what is the main effect of alpha blockers?
decreased peripheral resistance (due to vasodilation)
- increased CO and HR (due to catecholamines)
- -increased plasma volume (may cause edema and CV mortality)
what is the main effect of beta blockers w/o intrinsic sympathomimetic activity? what is it used for now?
decreased CO
- increased plasma volume
- -decreased renin (would initially increase due to decreased CO, but then normalizes to decreased renin)
used for AV node blocking in afib
what is the main effect of beta blockers w/ intrinsic sympathomimetic activity? what is it used for now?
decreased peripheral resistance
used for heart failure
what is the main effect of arteriolar vasodilators?
decreased TPR
-increased CO and HR (due to catecholamines)
what is the main effect of ACEi and ARBs?
decreased TPR (due to decreased AII)
what is the main effect of renin inhibitors?
decrease renin only (don’t work very well)
what are the most, less, and least commonly used anti-HTNs?
most: thiazides, ACEi, ARBs (angiotensin receptor blockers), CCBs
less: beta-blockers, alpha-blockers
rare: central-acting a2 agonists and adrenergic blocking agents
what are high, medium, and low potency diuretics? when are they used?
high: loops (competitively inhibit Na/K/Cl2 transporters in TAL)
- for severe HTN, in setting of CHF or cirrhosis, and with renal insufficiency (GFR < 30-40)
medium: thiazide (inhibits exchange of NaCl in distal ascending loop)
- for most mild-moderate HTN
low: K+ sparing diuretics (inhibit Na+ reabsorption in distal tubule)
- in combo with above 2 to help prevent hypokalemia
why are loop and thiazide diuretics contraindicated in DM?
can cause impaired glucose tolerance