Prioritization of Patient Care in a Telemetry Unit

A nursing team in a busy hospital is managing patient care on a telemetry unit. The patients include:

1. A 75-year-old male with a history of atrial fibrillation who is complaining of chest pain and has a heart rate of 150 beats per minute.

2. A 65-year-old female who is post-operative day 1 from a total knee replacement and reports a pain level of 8/10, but her vital signs are stable.

3. A 50-year-old male diagnosed with congestive heart failure who has edema on assessment and is showing signs of dyspnea.

4. A 30-year-old female with a new diagnosis of diabetes who is requesting education on insulin administration, but her blood glucose is within normal limits.

Considering the priorities of care and the immediate needs of these patients, which patient should the nurse assess first?