8.
A 65-year-old male presents to the emergency department complaining of severe, deep substernal chest pain, diaphoresis, and nausea. His initial 12-lead ECG demonstrates hyperacute ST-segment elevation in leads II, III, and aVF. On physical examination, his blood pressure is 85/50 mm Hg, and his heart rate is 92 beats/minute. You note prominent distended jugular veins, but auscultation of the lungs reveals completely clear lung fields bilaterally.
Which of the following is the most appropriate next step in the initial hemodynamic management of this patient?
Correct Answer: B) Administer an intravenous bolus of 0.9% saline
Explanation / Rationale: This patient’s clinical presentation—featuring ST-segment elevation in leads II, III, and aVF—indicates an acute inferior (diaphragmatic) ST-segment elevation myocardial infarction (STEMI). The classic triad of hypotension, elevated jugular venous pressure, and clear lung fields in the setting of an inferior STEMI strongly points to a complicating right ventricular (RV) infarction.
- Option B is correct: Patients with right ventricular infarction are highly preload-dependent. The appropriate initial management for hypotension in this setting is volume loading with 1 to 2 L of 0.9% normal saline to maintain right-sided filling pressures and improve cardiac output.
- Option A is incorrect: Nitrates (such as nitroglycerin) are powerful venodilators that reduce preload. In patients with RV infarction, reducing preload can severely compromise cardiac output and precipitate profound hypotension; therefore, they must be avoided.
- Option C is incorrect: Diuretics (such as furosemide) also reduce preload and can cause severe hypotension in the setting of RV ischemia. They are contraindicated in this scenario.
- Option D is incorrect: While beta-blockers are a standard part of therapy for acute MI to reduce cardiac workload and oxygen demand, they are specifically contraindicated in patients presenting with marked hypotension (systolic blood pressure < 100 mm Hg) or signs of cardiogenic shock.
Acute coronary syndrome