Practice Question
A nurse in an emergency department is caring for a client who reports substernal chest pain and dyspnea. The client is vomiting and is diaphoretic. Which of the following laboratory tests are used to diagnose a myocardial infarction? (Multiple Response- Select all that apply.)
Answer Choices:
Correct Answer:
Myoglobin.
Rationale:
Myoglobin
🔹 Myoglobin is an early marker released into the bloodstream when muscle injury occurs, including cardiac muscle.
🔹 It appears within 2 hours of myocardial injury and peaks around 3–15 hours.
🔹 While not specific to cardiac tissue, it is useful for early detection of myocardial infarction (MI).
🔹 It helps in ruling out MI if levels remain normal after chest pain onset.
🔹 It is often used in combination with more specific markers like troponins for accurate diagnosis.
Troponin T
🔹 Troponin T is a cardiac-specific protein, highly sensitive and specific for myocardial cell damage.
🔹 It begins to rise within 3–6 hours after injury and can remain elevated for 10–14 days, aiding in late diagnosis.
🔹 Elevated levels confirm myocardial infarction, even in the absence of ECG changes.
🔹 It is one of the gold-standard markers for MI diagnosis in emergency settings.
🔹 Troponin testing is central in evaluating chest pain and suspected cardiac events.
CK-MB (Creatine Kinase-MB)
🔹 CK-MB is an enzyme found primarily in cardiac muscle, making it a moderately specific marker for MI.
🔹 Levels begin to rise 4–6 hours after myocardial injury, peaking around 24 hours, and return to baseline in 2–3 days.
🔹 It is useful for detecting reinfarction due to its short half-life compared to troponins.
🔹 Elevated CK-MB levels support a diagnosis of acute MI, especially when used with troponin.
🔹 Serial measurements can help determine evolving infarction patterns.
Troponin I
🔹 Troponin I, like Troponin T, is highly specific to myocardial tissue and sensitive to damage.
🔹 It elevates 3–6 hours after MI, peaks at 12–24 hours, and stays elevated up to 7 days.
🔹 It is used to differentiate cardiac from non-cardiac chest pain.
🔹 Persistent elevation is useful in detecting myocardial injury, especially in unstable angina.
🔹 Troponin I is preferred in clinical practice due to its specificity and diagnostic reliability.
Want to practice more questions like this?
This question is from Custom: NUR 211 Midpoint Assessment- Summer 2 2025 which contains 29 questions.
More Questions from This Exam
A nurse is planning to teach a community group about preventative measures for heart disease. Which of the following recommendations should the nurse include in the teaching plan? (Select All that Apply.)
Answer Choices:
A nurse is assessing a toddler who has heart failure. Which of the following findings should the nurse expect?
Answer Choices:
A nurse is assessing a 3-year-old child who has aortic stenosis. Which of the following findings should the nurse expect? (Select All that Apply.)
Answer Choices:
Which of the following are the most common manifestations of COPD? (Select all that apply.)
Answer Choices:
A nurse is caring for a client with asthma. Which of the following happens physiologically when bronchospasm occurs?
Answer Choices:
From Exam
Custom: NUR 211 Midpoint Assessment- Summer 2 2025
29 Questions
View Full Exam Start PracticingQuestion Details
- Category: RN Nursing Exam(s)
- Subcategory: ATI Exam(s)
- Domain: RN Custom Exam(s)
- Answer Choices: 5