Which of the following is the first step in respiration? a. oxygen passes into capillaries to the blood. b. oxygen is taken into the lungs. c. carbon dioxide passes into capillaries to the blood. d. carbon dioxide passes from the blood to the lungs.

A62-year-old man is being treated for an acute myocardial infarction. he originally came to the ed with substernal chest pain and diaphoresis. given his risk factors of hypertension, diabetes, tobacco use, and family history, he is considered high risk. an ecg in the ed reveals a left-bundle branch pattern, and cardiac enzymes are elevated slightly. after a focused evaluation in the ed, the patient receives iv thrombolytics. although his bundle branch pattern never resolves, the patient is chest pain-free and haemodynamically stable after thrombolysis. two days later, however, the patient reports episodes of recurrent chest discomfort and shortness of breath overnight. in evaluating for potential myocardial reinfarction, which of the following is the most appropriate diagnostic test? - creatinine kinase- dynamic ecg changes- lactate dehydrogenase- myoglobin levels- troponin i level