A client is admitted with chest pain and is rubbing the left arm. The nurse initiates oxygen at 4 L/minute, and administers a dose of aspirin PO, nitroglycerin sublingually, and morphine sulfate IV. Which additional assessment should the nurse consider for a myocardial infarction (MI)?

A. Normal coagulation studies: While important for evaluating bleeding risk, coagulation values do not confirm or exclude myocardial infarction. They are more relevant when planning invasive procedures or anticoagulation, not in the acute diagnosis of MI. B. ST segment elevation: ST segment elevation on a 12-lead ECG is a critical diagnostic indicator of an ST-elevation myocardial infarction (STEMI). Recognizing this finding guides urgent reperfusion therapy such as PCI or thrombolytics, making it a key priority assessment. C. Premature ventricular contractions (PVC): PVCs may occur during or after an MI due to myocardial irritability, but they are not diagnostic. Isolated PVCs do not provide definitive evidence of infarction and may be seen in various other cardiac conditions. D. Relief of chest pain: Pain relief is an important treatment goal, but it is a response to intervention, not a diagnostic tool. Monitoring pain helps evaluate effectiveness of therapy, but confirming the MI requires objective findings like ECG changes.