lexiscan

Question 1

lexiscan dose

Answer 1

5mL (0.4mg)

Question 2

what are the 4 types of adenosine receptors

Answer 2

A1, A2A, A2B, A3

Question 3

where are adenosine receptor located

Answer 3

located in various tissues through the body (AV node, pulmonary, periphreal vessels, coronary vessels)

Question 4

what is the A2A receptor responsible for

Answer 4

mediates coronary vasodilation (peak effect ~30 sec after inj)

Question 5

what is the potency of the agonist determined by

Answer 5

affinity for its receptor

Question 6

high affinity=

Answer 6

binds readily and remains bound (prolonged response)

Question 7

low affinity=

Answer 7

bind less tightly and disassociates quickly (physiological response terminates quickly)

Question 8

duration for low affinity

Answer 8

short

Question 9

duration for high affinity

Answer 9

long

Question 10

lexiscan has a ____affinity for ________ ______ ______

Answer 10

low, adenosine receptor agonist

Question 11

coronary arteris have a high densisty of____ which causes_____

Answer 11

A2A receptors and only need to activate a fraction of them to reach max coronary vasodilation

Question 12

what is the chemical structure of lexiscan

Answer 12

modified form of adenosine molecule w/ additional side chain

Question 13

A2B ad A3 are responssible for

Answer 13

bronchoconstriction, a major issue seen with adenosine use

Question 14

lexi effects the A2A adenosine receptor agonist w/o activating other three receptors

Answer 14

which is good

Question 15

A2A receptor =

Answer 15

reduction in chest pain and nausea side effetc and slight inc in SOB

Question 16

symptoms start to dissipate about

Answer 16

5-15 min after

Question 17

3 T1/2 of lexi

Answer 17

intial phase=2-4 min
intermediate phase=30 min
terminal phase=2 hrs

Question 18

low level exercise can be done w lexi which includes benefits such as

Answer 18

help we decrease in side effects, clear GI uptake for better image quality, quicker imaging

Question 19

inj regadenoson over how many sec

Answer 19

10 sec

Question 20

inj saline over how many sec

Answer 20

same pace as reg- 10 sec

Question 21

inj radiotracer how many sec after flush

Answer 21

10-20 sec

Question 22

side effetcs of regadenoson

Answer 22

headache, dyspnea, flushing, chest pain/discomfort, nausea./abd discomfort, rhytym abnormality

Question 23

what is common to see after reg inj

Answer 23

modest HR incr and decr in BP

Question 24

contraindications to reg

Answer 24

same as adenosine

Question 25

headache is only symptom that take a little longer to rid

Answer 25

30 min

Question 26

how much aminophylline can be given

Answer 26

50-250 mg

Question 27

how long do you have to wait to give aminophylline

Answer 27

at least 1 min after reg inj

Question 28

what more serious events have been reported with aminophylline use

Answer 28

stroke, MI, ischemia, A-fib, A-flutter, seizures

Question 29

steps for a walking lexi

Answer 29

-12 series EKG (limbs, supine, standing)
-10-20 sec of walking at 0.8 mph (warm up)
- once pt comfy inject reg
-walk at 1 mph
-10-20 sec later inj regadenoson
-EKG monitored for 4 min