Final answer:
The appropriate test for a 51-year-old man with diabetes, hypertension, and left-sided jaw pain after shoveling snow is an electrocardiogram (ECG), not Panorex X-rays, due to the potential for a cardiovascular event.
Step-by-step explanation:
A 51-year-old man with a history of diabetes mellitus and hypertension presents with left-sided jaw pain after exertion, such as shoveling snow. Given his risk factors and symptom presentation, the priority test to order is an electrocardiogram (ECG).
The ECG is essential for evaluating the electrical activity of the heart and for ruling out cardiac causes like angina or myocardial infarction, which can present with referred pain to the jaw. A Panorex X-ray, typically useful for dental issues, is not the appropriate first response in this acute scenario. The man's combination of diabetes, hypertension, and exertional left-sided jaw pain indicates a potential cardiovascular event that requires immediate attention.