Chapter 11: Cardiovascular A/P & Antihypertensives Flashcards
Test 2
SBP =
120
DBP =
70-80
Blood volume
Female: 4-5 L
Male: 5-6 L
MAP =
DBP + 1/3(SBP -DBP)
Increasing EDV and Decreasing ESV =
Increasing Stroke volume
What is the Hydraulic equation?
Calculates BP
BP = CO x PVR
** Rember CO = HR x SV !!!!!**
What sense a drop in BP?
Baroreceptors in the carotid arteries
What are the 4 anatomical site of BP control?
- Resistance Arterioles
- Capacitance Venules
- Pump output heart
- Volumr Kidneys
In blood vessles, if resistance increases, then ______ pressure is needed to keep the blood moving
more
What are the 3 main sources of peripheral resistance?
- blood vessel diameter
- blood viscosity
- blood vessel length (wt effects this)
What is the most common CV disease?
HTN
T/F: Kidneys are the 2nd target when trying to lower BP
F
First; they respond quickest
Describe how the kidneys respond to a drop in BP
- The kidneys stimulate Renin in the juxtaglumerular cells
- The liver produces Angiotensinogen which is inactive
- Renin active angiotensinogen to angiotensin I in the lungs
- Angiotensin Converting Enzyme converts Angiotensin I to angiotensin II
- Angiotension II acts on the blood vessels and causes vasoconstriction while also acting on the adrenal gland causeing it to secrete aldosterone.
- Aldosterone increases sodium reabsorption which causes water reabsorption.
- The ultimate increase in BP causes a decreases in Renin secretion (negative feedback)
What type of drugs lower BP?
Diuretics
Alpha/Beta Blockers
Direct Vasodilators
ARBs
ACE inhbitors
CCB
Drugs: Clonidine
A2 agonist
CNS sympathoplegics
Partial agonist prevents full agonist from binding
lipid soluble- rapidly enters brain
primary activary at RVLM at brainstem
Activates Vagus nerve
SE: sedation, dry mouth
Drugs: Methyldopa
A2 agonist
CNS sympathoplegics
PRODRUG has to be activated
primary activary at RVLM at brainstem
Activates Vagus nerve
Good for pregnant women doesnt cross placental barrier d/t not being as lipid soluble
Tx: HTN
SE: sedation
Drugs: Precedex
A2 agonist
CNS sympathoplegics
Uses: Sedation
Drugs: Propanolol
Beta Blocker
B1/B2 - nonspecific
Decreases CO
INHIBITS RENIN PRODUCTION
Prevents reflection tachycardia
What medication would you give to a pregnant lady to lower BP?
Methyldopa
What beta blocker inhibits renin?
Propanolol
T/F: When you give clonidine you see immediate prolonged hypotension
F
Brief rise, then prolonged hypotension
The more specific the drug is to a receptor the ______ the drug is
Safer
Why is Metoprolol a better choice for lowering BP than propranolol?
Propranolol is nonspecific. it works on B1 and B2 receptors which works in the lungs too. If i have asthma… this will cause the bronchials in my lungs to constrict more.
T/F: Beta Blockers, Diuretics, and vasodilators are best used in conjunction
T
What is a side effect of Alpha-1 blockers?
Retention of salt and water
Drugs: Hydralazine
Vasodilator
induces NO production in endothelium
low bioavailability
Drugs: Minoxidil
Vasodilator
Opens k+ channels in smooth muscle to hyperpolarize cell
Rogaine – SE: grows hair, angina
well aborbed
Drugs: Nitroprusside
Vasodilator
Breaks down in blood to release NO
Works on Arteries and veins
Continuous IV infusion
Protect from light
Tx: HTN emergency, Cardiac failure
What happens if you reach high rates in Nitroprusside?
CN (cyanide) accumulation/posioning
What organ eliminated CN?
Kidneys
What metabolized CN?
Sodium thiosulfate
Would you give Nitroprusside to a pt in kidney failure? Why?
No.
CN accumulation even faster.
Drugs: Fenoldopam
Vasodilator
Dopamine-1 agonist
Continuous IV infusion
Tx: HTN emergency, post-op HTN
