This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Medicine
[{'content': 'Neurocardiogenic syncope which is true? \nSelect and explain. \nA. Vasodilation and bradycardia, B. Initiated at lv, C. Forceful contraction of heart, D. Heart chambers filled with blood', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (A) Vasodilation and bradycardia> Fainting due to bradycardia, heart block, or sinus arrest is called neurocardiogenic syncope. In addition, fainting is the presenting symptom in 7% of patients with myocardial infarctions. Thus, all cases of syncope should be investigated to determine the cause.', 'role': 'assistant'}]