This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Rheumatic Hea disease & infective endocarditis, Subject name: Medicine
[{'content': 'A 60-year-old patient presents with recurrent TIA episodes. Echocardiography shows candle flame sign. The probable etiology of the disease is? \nSelect and explain. \nA. Senile calcification of hea valve, B. Rheumatic fever when he was a youth, C. Long-standing undiagnosed hypeension, D. Undiagnosed congenital condition', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The clue is candle flame sign on echo which is a feature of mitral stenosis. Hence the answer is B. In longstanding mitral stenosis, left atria appendage clots can develop. This can explain the neurological presentation of this patient. Most common valvular cause of RHD is mitral stenosis at young age .', 'role': 'assistant'}]