This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Medicine
[{'content': 'Which of the following is the most striking difference in the cardiac actions of epinephrine and norepinephrine? \nSelect and explain. \nA. heart rate, B. stroke volume, C. cardiac output, D. arrhythmias', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Epinephrine results in a more rapid heart rate and more powerful systolic contraction resulting in increased cardiac output. Norepinephrine results in an unchanged or even decreased cardiac output.', 'role': 'assistant'}]