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
[{'content': 'Aggrevation of symptoms of angina in a patient when given nitrates is seen in \nSelect and explain. \nA. Aoic regurgitation, B. Mitral regurgitation, C. Single left coronary aery stenosis, D. Idiopathic hyperophic subaoic stenosis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ref Harrison 19 th ed pg 1568 Idiopathic hyperophic cardiomyopathy ( HOCM) is a dynamic outflow obstruction which is increased by any mechanism decreasing the preload . Nitrates decrease the preload,the volume of blood in LV and thereby increase the dynamic obstruction and symptom of angina', 'role': 'assistant'}]