Priority Intervention for Hemodynamic Instability

A 57-year-old male patient with a history of hypertension and type 2 diabetes presents to the emergency department with complaints of chest pain and shortness of breath. His vital signs show a blood pressure of 88/58 mmHg, heart rate of 110 beats per minute, and respiratory rate of 24 breaths per minute. An ECG reveals sinus tachycardia with no acute ST elevation. Laboratory tests indicate elevated troponin levels. Which of the following interventions is the priority for this patient to address his current hemodynamic status?