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: Medicine
[{'content': 'Gradient in pulmonary aery wedge pressure and left ventricular end diastolic pressure is seen in \nSelect and explain. \nA. Aoic regurgitation, B. Constrictive pericarditis, C. Left atrial myxoma, D. Pulmonary thromboembolism', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Answer is C (Left atrial myxoma) An increased gradient during diastole is suggestive of an obstructive lesion between Left atrium and Left ventricle that is not allowing pressures to normalize between the atria and ventricle such as atrial myxoma. Pulmonary aery wedge pressure represents Left atrial pressure. Left ventricular end diastolic pressure represents Left ventricular pressure. Gradient between Left atrial pressure (PCWP) and Left ventricular pressure during diastole: Normally there is no gradient during diastole as both pressures are equal. An increased gradient during diastole is suggestive of an obstructive lesion between Left atrium and Left ventricle that is not allowing pressures to normalize between the atria and ventricle. This may thus be seen in obstructive lesions between Left atria and ventricle such as : Mitral stcnosis Atrial myxomas', 'role': 'assistant'}]