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
All are contraindications of digitalis except 
Select and explain. 
A. Carditis, B. Increased calcium, C. AV block, D. Hepatic failure
B: Increased calcium
Answer: B: Increased calcium 
Explanation: 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