This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Electrocardiography, Subject name: Medicine
[{'content': 'PR interval is reduced in ? \nSelect and explain. \nA. Wenckebach phenomenon, B. WPW syndrome, C. Hypothyroidism, D. Complete heart block', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., WPW syndrome o In WPW, the bundle of Kent is an accessory pathway which allows fast conduction to the ventricles and consequently leads to complaints of palpitations and reduction of PR interval.PR interval has an inverse relation with heart rateo All other options are characterized by bradycardia therefor PR interval increased.", 'role': 'assistant'}]