A nurse admits a client to the emergency department who reports nausea, vomiting, and epigastric pain that worsens when lying down. The provider suspects acute pancreatitis. Which of the following laboratory test results should the nurse expect to see?

Choice A reason: A 12-lead ECG can reveal changes in the ST segment, T wave, and QRS complex, which are indicative of myocardial ischemia, injury, or infarction. It is the first line diagnostic test that needs to be recorded within 10 minutes after the first medical contact in cases of suspected acute coronary syndromes.

Choice B reason: While pain radiating to the left arm can be a symptom of MI, it is not a definitive diagnostic action. It is a common symptom but can also be associated with other conditions.

Choice C reason: Checking the client's blood pressure is important in the overall assessment of the client's cardiovascular status but does not specifically diagnose MI. Blood pressure can be normal, elevated, or decreased in the case of MI.

Choice D reason: Auscultating heart tones can provide information about the presence of murmurs, gallops, or rubs, but it is not a specific diagnostic action for MI. Heart sounds may be normal during an MI.

Choice A: Troponin Troponin levels increase within 3-12 hours from the onset of chest pain, peak at 24-48 hours, and return to baseline over 5-14 days. Troponin is a protein found in cardiac muscle fibers that regulates muscular contraction. When heart muscle is damaged, as in the case of an MI, troponin is released into the bloodstream. The elevation of troponin levels is a key indicator of myocardial infarction and can be used to diagnose and assess the extent of heart muscle damage. Troponin is the most reliable laboratory value that is expected to be elevated following a myocardial infarction, making it the correct choice in this scenario.

Choice B: Aspartate aminotransferase (AST) AST is an enzyme found in high concentrations in the liver, heart, muscles, kidneys, and brain. It is released into the bloodstream when any of these tissues are damaged. While AST can be elevated in cases of MI, it is not as specific as troponin because it is present in many other tissues besides the heart.

Choice C: Serum amylase Serum amylase is an enzyme that helps digest carbohydrates and is primarily associated with the pancreas and salivary glands. Its elevation is not specifically related to myocardial infarction but can be seen in other conditions such as pancreatitis.

Choice D: Unconjugated bilirubin Unconjugated bilirubin is a breakdown product of hemoglobin from red blood cells. Elevated levels of unconjugated bilirubin are typically associated with conditions affecting the liver or the breakdown of red blood cells, not myocardial infarction.