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
[{'content': 'Nitrates decrease myocardial oxygen consumption by all of the following mechanisms EXCEPT: \nSelect and explain. \nA. By increasing the left ventricular end diastolic pressure, B. By direct reduction of oxygen consumption of myocardial the cell, C. By dilation of the capacitance vessels, D. By decreasing the size of hea', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Nitrates decrease the ventricular end diastolic pressure by decreasing end-diastolic ventricular volume they cause venodilation, decreases oxygen consumption by hea and en diastolic pressure They are mainly useful in treating angina. REF.Essentials of Pharmacology KD Tripathi 8th ed.', 'role': 'assistant'}]