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Radiology · Radiotherapy and nuclear medicine basics: pharmacological stress agent
Sample itemA patient with severe active asthma cannot exercise and needs stress myocardial perfusion imaging. Which stress agent is preferred?
Original practice item, not a recalled exam question. Nothing here is recorded.
The answer and the reasoning
B. Dobutamine
Adenosine and dipyridamole act through adenosine receptors and can precipitate bronchospasm, so they are avoided in active reactive airway disease. Dobutamine increases heart rate and contractility and is the usual alternative. Aminophylline is used to reverse the effect of vasodilators, not to stress the heart.
Option by option
A. Dipyridamole
Dipyridamole raises adenosine levels and can cause bronchospasm.
B. Dobutamine (correct)
Correct. Dobutamine does not act on adenosine receptors and does not provoke bronchospasm.
C. Aminophylline
Aminophylline is an antagonist used to reverse vasodilator stress.
D. Adenosine
Adenosine can cause severe bronchospasm.
Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.
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