Priority Action for Chest Pain in Emergency

A 45-year-old male presents to the emergency department with severe chest pain radiating to his left arm and diaphoresis. His vital signs are as follows: blood pressure 90/60 mmHg, heart rate 120 beats per minute, and respiratory rate 24 breaths per minute. The patient appears anxious and is clutching his chest. Based on the provided information, which priority action should the nurse take to address this medical emergency?