Pharmacological Stress Test Flashcards
Other name for dipyridamole
Persantine
Pt prep for adenosine and dipyridamole
- NPO 4 hours
- D/C xanthine derivatives (aminophylline, theophylline, caffeine) 12-34 hours prior
How does dipyridamole work
Vasodilation
Indirectly increases adenosine
Contraindications of dipyridamole
History of bronchospasm or pulmonary disease, active wheezing, low BP, mitral valve disease
Reversal of dipyridamole
Aminophylline
Aminophylline dose
50-250 mg
50-100 over 30-60 seconds
Dipyridamole dose and administration
0.56 mg/kg in 50 ml saline
Infused over 4 minutes
When is tracer injected when using dipyridamole
Within 5 minutes AFTER the infusion has ended
How does adenosine work
Vasodilation
Directly increases adenosine
Contraindications for adenosine
Same as dipyridamole + 2nd or 3rd degree AV block (without a pacemaker)
Half life of adenosine and dipyridamole
<2 seconds
Reversal of adenosine
Aminophylline
Adenosine dose and administration
240 ug/kg
Infused over 6 minutes
When is tracer injected with adenosine?
3 minutes into 6 minute infusion
Must have 2 IV lines
How does regadenoson work
A2A adenosine receptor that produces coronary vasodilation
Maximum plasma concentration of regadenoson
1-4 minutes after injection
Regadenson pt prep
- avoid methylxanthines 12 hours prior (caffeine, decaf, theophylline)
- d/c dipyridamole 2 days prior
Contraindications for regadenoson
2nd or 3rd degree AV block, sinus node dysfunction, bronchospasm, low BP
Reversal of regadenson
Aminophylline
50-250mg (50-100 over 30-60 seconds)
Regadenson dose and administration
0.4 mg in 5 ml over 10 seconds
When to inject tracer when using regadenoson
10-20 seconds after regadenoson
Advantages of combination of low level exercise + pharmacological stress agent
Decrease side effects and subdiaphragmatic uptake
Increase target to background ratio
How does dobutamine work
Stimulates B1 receptors
Enhances the force of the hearts contractions and heart rate
Which agent is most similar to exercise
Dobutamine
