10 Integrated Cardiac Pharmacology

Question 1

where is the ANS cardiac control center in the CNS?

Answer 1

rostral ventrolateral medulla(RVLM)

nucleus tractus solitarius(NTS)

Question 2

what type of pressure are baroreceptors sensitive to?

Answer 2

pulse pressure

if the pulse pressure decreases, but mean pressure is the same, baroreceptor rate of discharge will still decrease

Question 3

autonomic predominance in vasculature

Answer 3

sympathetic is the only innervation

vasoconstriction in arterioles and venules

cholinergic vasodilation in skeletal muscle arterioles

no PSYMP INNERVATION; M3 receptors in endothelium are not connected to nerves

Question 4

stimulation of vagal c fibers arises from where?

effect?

Answer 4

atria, ventricles, great veins, pulmonary arteries, alveoli capillaries

bradycardia, hypotension, brief apnea- bezold-jarisch reflex

Question 5

during exercise how is the sympathetic vasoconstriction of exercising muscle overcome to allow required perfusion

Answer 5

local vasodilators

stimulation of cholinergic vasodilatory fibers

Question 6

dynamic whole body exercises affect the TPR how?

Answer 6

drop!

baroreceptors are not triggered

Question 7

stages of valsalva maneuver

Answer 7

strain

1. increased MAP, decreased HR(compensatory)
2. decreased CO/MAP(less return), increased HR(compensatory)

release

1. transient MAP decrease, CO is restored
2. MAP ramp up w/compensatory drop in HR

Question 8

cause of neurocardiogenic syncope

Answer 8

cardioinhibitory - increased PSYMP tone, bradycardia

vasodepressor - decreased sympathetic tone, hypotension

mixed - both HR and BP depressed

widely accepted theory: vagal afferents affect NTS to mediate these presentations

Question 9

potential triggers for neurocardiogenic syncope

Answer 9

pain

visual stimuli

noxious stimuli

excessive standing(pooling)

Question 10

exacerbation of neurocardiogenic syncope

treatment?

Answer 10

dehydrtation

anxiety

exogenous catecholamines

treatment: drink water, eat salt, shift weight while standing

Question 11

tilt table test

Answer 11

• Pt lays horizontal and strapped down
• HR, ECG, BP recorded
• Table elevated to 70/80 deg
• Room darkened
• If no syncope after 20 min, isoproterenol is administered IV for 20 min(increase HR, decrease BP)
• Test considered negative if no event @ 40m