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': 'Digoxin use in CHF associated with: \nSelect and explain. \nA. HOCM (Hyperophic obstructive cardiomyopathy), B. High output failure, C. Atrial fibrillation with high ventricular rate, D. All of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Digitalis is used for controlling the ventricular rate in atrial fibrillation. Digitalis reduces ventricular in atrial fibrillation by decreasing the number of impulses that are able to pass down the AV node and bundle of his. It increases ERP of AV node by direct, vagomimetic and antiadrenergic actions. Essentials of medical pharmacology, seventh edition, KD Tripathi, page no:519', 'role': 'assistant'}]