This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: CHF, Angina Pectoris and Myocardial Infarction, Subject name: Pharmacology
Which of the following drug can cause coronary steal phenomenon? 
Select and explain. 
A. Hydralazine, B. Glyceryl trinitrate, C. Disopyramide, D. Diltiazem
A: Hydralazine
Answer: A: Hydralazine 
Explanation: Coronary steal phenomenon:* Caused by drugs which dilate small vessels only.* Atherosclerotic vessels are maximally dilated already, so fuher administration of vasodilators leads to more dilation of normal vessels rather than atherosclerotic one, blood supply to ischemic area is taken towards dilated small vessel - STEALING Coronary steal phenomenon is shown by: -H- HydralazineI- IsofluraneD- DipyridamoleE- Enflurane