This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
Prinzmetal angina is - 
Select and explain. 
A. Angina after extreme exeion, B. Caused due to atherosclerotic blockade, C. Caused due to spasm of aery, D. Calcium channel blockers not effective
C: Caused due to spasm of aery
Answer: C: Caused due to spasm of aery 
Explanation: Ref: R. Alagappan Manual of Practical Medicine. 4th Edition pg no:79 Prinzmetal Angina Prinzmetal angina is a type of angina pectoris, which typically occurs during rest and may recur in a nightly cyclic pattern. ST-segment elevation or depression on the electrocardiogram and coronary aery spasm have been documented during an attack.