Which laboratory value should the nurse review to validate a diagnosis of a myocardial infarction (MI) that was suspected of occurring approximately 3 hours earlier?

Question

Quizplus · Accepted Answer

1. Creatinine phosphokinase (CK) serum levels peak between 12 and 14 hours and return to normal after 72 to 96 hours. Therefore, it would not help during the first few hours to validate an MI.
2. Troponin T assay is the most sensitive for cardiac damage but does not appear in the bloodstream until 4 to 12 hours after the damage occurs. It returns to normal after 4 to 10 days.
3. Myoglobin will peak between 1 and 4 hours after the hypoxic/necrotic event and return to normal in 24 hours. Therefore, it is the first to rise when tissue damage has occurred.
4. PTT does not measure tissue damage; it measures serum clotting times for anticoagulant therapy. Therefore, it would not validate when or if an MI occurred.

Which Laboratory Value Should the Nurse Review to Validate a Diagnosis