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': 'A child presented with headache, dizziness, intermittent claudication with occasional dyspnoea.The most probable diagnosis in – \nSelect and explain. \nA. ASD, B. PDA, C. TOF, D. Coarctation of aorta', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Clinical manifestations of COA \n\nSymptoms of coarctation of aorta occurs due to decrease in blood supply distal to aortic obstruction.\nIf obstruction is distal to left subclavian artery, manifestations are due to arterial insufficiency to lower limbs.\nIntermittent claudication\nPain\nWeakness of Leg\nDysnea on running\nWeak pulses and lower BP in the lower extremities --> Delayed or weak impalpable femorals compared to strong brachial arteries.\nCollateral circulation develops between precoarctation arterial branches and the post coarctation arteries through enlarged intercostal and internal mammaty arteries.\nThis produces radiologically visible erosions (notching) of undersurface (inferior) of ribs.\nHypertension --> Headache, dizziness.\nIf the obstruction is proximal to left subclavian artery ---> Blood supply to left arm (supplied by left subclavian) is interrupted whereas blood supply to right arm is normal -* Pressure difference in two arms.\n\nMurmur in coarctation of aorta \n\nThe blood passing through the narrowed aorta —> Midsystolic murmur in anterior part of chest, back and spinous process.\nWhen lumen becomes severly narrowed the blood flow through it, turns into a high velocity jet -p Continous murmur.\nCOA is associated with bicuspid aortic valve in 50-80% of patients. The bicuspid valve produce aortic regurgitation Diastolic murmur.', 'role': 'assistant'}]