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': 'All are contraindications of digitalis except \nSelect and explain. \nA. Carditis, B. Increased calcium, C. AV block, D. Hepatic failure', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Digoxin is contraindicated in .... Myxedema low amount of potassium in the blood hyperophic cardiomyopathy atrioventricular hea block Wolff-Parkinson-White syndrome ventricular fibrillation sick sinus syndrome sinus bradycardia Amyloid Hea Muscle Disease kidney disease with a likely reduction in kidney function Ref: KD tripathi 8th ed', 'role': 'assistant'}]