A 58-year-old male arrives at the emergency department reporting severe, crushing substernal chest pain accompanied by profuse sweating that began one hour ago. On physical examination, he is pale and visibly uncomfortable. Jugular venous distention is prominently noted, but auscultation of the lungs reveals clear breath sounds bilaterally without crackles. Vital signs demonstrate a blood pressure of 78/50 mm Hg, a heart rate of 54/min, a respiratory rate of 16/min, and an oxygen saturation of 97% on room air. An electrocardiogram obtained at triage displays prominent ST-segment elevations in leads II, III, and aVF. Intravenous access is rapidly secured. What is the most appropriate initial step in the stabilization of this patient?
- Rapid infusion of isotonic crystalloidAnswer
- BPlacement of a sublingual nitroglycerin tablet
- CInjection of intravenous furosemide
- DAcquisition of a computed tomography pulmonary angiogram
- ETransfer to the intensive care unit for central venous monitoring
Answer
Rapid infusion of isotonic crystalloid.
The patient is presenting with an acute inferior wall myocardial infarction complicated by right ventricular involvement. This is characterized by the classic clinical triad of hypotension, elevated jugular venous pressure, and clear lungs on auscultation. Because the ischemic right ventricle loses its contractility, it becomes entirely dependent on venous return (preload) to propel blood through the pulmonary circulation to the left ventricle. Therefore, the immediate life-saving stabilization step is the rapid administration of isotonic crystalloids. This intervention increases right-sided filling pressures, restoring stroke volume and cardiac output.
Step-by-Step Solution
Key Concept
In right ventricular myocardial infarction, the ischemic right ventricle is highly preload-dependent; initial stabilization requires rapid volume expansion with isotonic crystalloids, while preload-reducing agents (nitrates, diuretics) are strictly contraindicated.