This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
[{'content': 'The drug of choice in digitalis-induced ventricular arrhythmias is \nSelect and explain. \nA. Lignocaine, B. Phenytoin, C. Quinidine, D. Procainamide', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Lignocaine suppresses ventricular arrhythmias. It acts by blocking the sodium channel in the inactivated and active states. It is less toxic and has a rapid onset of action and sho duration of action. It has no action on A-V nodal conduction velocity. 1st DOC is lidocaine, 2nd DOC is phenytoin Lidocaine is class IB antiarrhythmic Ref: Tripati 8th edition', 'role': 'assistant'}]