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: Pediatrics
[{'content': 'Essential criteria for TOF includes all except – \nSelect and explain. \nA. Valvular stenosis, B. Infundibular stenosis, C. Overriding of aorta, D. RVH', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Right ventricular outflow obstruction is one of the characteristics of tetralogy of Fallot.\n\nThis right ventricular outflow obstruction is mainly caused due to infundibular stenosis.\nPulmonary valve stenosis (alone) rarely contributes to the right ventricular outflow obstruction in tetralogy of fallot.\nHurst cardiology says\n"The pulmonary valve is often malformed, usually being either biscuspid or unicuspid. The valve may contribute to pulmonary stenosis, but, only uncommonly, it is the only site ofsignificant obstruction to the pulmonary.flow".\nCauses of right ventricular outflow tract obstruction.\n\nInfundibular stenosis (45%)\nObstruction at the pulmonary level (10%).\nCombination of infundibular and valvular obstruction (30%).\nPulmonary atresia (15%).', 'role': 'assistant'}]