Prioritizing Complications Post-Myocardial Infarction

A 55-year-old patient with a history of hypertension presents to the emergency department with complaints of severe chest pain radiating to the left arm and jaw, diaphoresis, and shortness of breath. An ECG reveals ST-segment elevations in the inferior leads. The physician suspects an inferior wall myocardial infarction (MI). After stabilizing the patient, the nursing staff is instructed to monitor for potential complications of myocardial infarction. Which complication should the nurse prioritize in the immediate post-MI phase?