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': 'Wolff - Parkinson - White (WPW) syndrome is characterised by \nSelect and explain. \nA. Prolonged PR interval, B. Delta wave, C. U wave, D. Heart block', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (Delta wave) (1316, 1351-H) (1393-H17th)WPW-Svndrome - Triad consist of(I) Wide QRS complex associated with relatively short PR interval (0.12s)(II) Slurring of the initial part of the QRS {delta wave)(III) Aberrant activation of ventricular myocardiumTreatment of WPW syndrome and AF(I) DC cardioversion (life threatening)(II) Lidocaine or procainamide (non-life threatening situations)', 'role': 'assistant'}]