This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Digoxin is contraindicated in - \nSelect and explain. \nA. Supraventricular tachycardia, B. Atrial fibrillation, C. Congestive hea failure, D. Hyperophic obstructive cardioinyopathy', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Hyperophic obstructive cardiomyopathy Digitalis is contraindicated in o HOCM - By increasing the contractility it decreases the size of ventricle --> obstruction. o Paia1A-V block - Digitalis increases ERP of A-V node --> A.V. conduction --> may conve paial block into complete block. o WPW syndrome - Digitalis slows the conduction in the normal AV bundle and accelerates it in the aberrant pathway --> increase chances of reentry --> ventricular fibrillation may occur. o Ventricular tachycardia - Digitalis decreases the refractory period of ventricle muscle ventricular fibrillation may occur.", 'role': 'assistant'}]