This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Emergency Clinical Scenario, Subject name: Medicine
[{'content': 'Hockey-stick appearance in echocardiography is a feature of? \nSelect and explain. \nA. Mitral stenosis, B. Mitral incompetence, C. Aoic stenosis, D. Aoic regurgitation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: HOCKEY STICK SIGNS ECG Digoxin effect Echocardiography Mitral stenosis. Normal, biphasic, and rapid motion of the mitral valve is altered because it opens only paly and as a single unit. The posterior leaflet becomes immobile and the anterior mitral leaflet tethering results in a "hockey stick" appearance. These changes obstructs the blood flow from the atrium to the ventricle MRI Brain Hockey-stick sign of v CJD FLAIR image shows symmetrical pulvinar and dorsomedial thalamic nuclear hyperintensity. This combination gives a characteristic "hockey-stick"appearance.', 'role': 'assistant'}]