a history of periodic chest pain for which she uses nitroglycerine sublingually, but today mediations did not relieve the pain. Her blood

pressure is 140/100 mm Hg, pulse – 130/min, respiratory rate – 18/min, temperature – 37oC. A bedside electrocardiogram shows ST-segment

elevation in leads II, III, and a VF. Blood is drawn and sent to the lab, which is positive for specific biomarker. A diagnosis of acute

inferior myocardial infarction is made, and the patient is sent to the catheterization lab for angioplasty with stent placement. Which of

the following is the most likely specific and sensitive biomarker of cardiac injury?