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Difficulty: HardInitial Stabilization and Triage

A 61-year-old man arrives at the emergency department reporting severe, crushing substernal chest pain that radiates to his jaw, accompanied by profound diaphoresis and nausea. The symptoms began abruptly 45 minutes prior. His past medical history is notable for hypertension, type 2 diabetes mellitus, and hyperlipidemia. Vital signs are temperature 36.8°C (98.2°F), heart rate 112/min, blood pressure 74/48 mm Hg, respiratory rate 22/min, and oxygen saturation 96% on room air. Physical examination reveals elevated jugular venous pressure with prominent a-waves. Pulmonary auscultation reveals clear breath sounds bilaterally without crackles or wheezes. A 12-lead electrocardiogram demonstrates 3-mm ST-segment elevations in leads II, III, and aVF, with reciprocal ST-segment depressions in leads I and aVL. Which of the following is the most urgent initial step in the management of this patient?

  1. Intravenous normal saline bolusAnswer
  2. B
    Administration of sublingual nitroglycerin
  3. C
    Transthoracic echocardiography
  4. D
    Urgent cardiology consultation for percutaneous coronary intervention
  5. E
    Computed tomography angiography of the chest

Answer

Intravenous normal saline bolus
The clinical triad of hypotension, elevated jugular venous pressure, and clear lung fields in the setting of an inferior wall myocardial infarction (ST elevations in II, III, and aVF) is highly specific for a right ventricular infarction. The ischemic right ventricle loses its contractile force and becomes exquisitely dependent on adequate preload to push blood into the pulmonary circulation and subsequently to the left heart. The immediate stabilization step is administering intravenous isotonic crystalloids to increase right-sided filling pressures and restore cardiac output.

Step-by-Step Solution

1
Analyze the clinical presentation and diagnostic findings.
The patient has hypotension, elevated jugular venous pressure, clear lung fields, and an electrocardiogram showing an inferior ST-segment elevation myocardial infarction (STEMI).
Recognizing this classic triad is necessary to diagnose right ventricular myocardial infarction.
2
Identify the underlying pathophysiology causing the hemodynamic instability.
The ischemic right ventricle loses contractility, making it exquisitely dependent on adequate preload to maintain forward blood flow to the left ventricle and systemic circulation.
Understanding the mechanism of cardiogenic shock in this specific context dictates the correct treatment pathway.
3
Determine the most urgent initial step for hemodynamic stabilization.
Administer an intravenous normal saline bolus to maximize right-sided filling pressures.
Hemodynamic stabilization (ABCs) must precede or occur concurrently with definitive diagnostic workup and subspecialty interventions.

Key Concept

Patients with right ventricular myocardial infarction (characterized by hypotension, elevated JVP, clear lungs, and inferior STEMI) are highly preload-dependent and require immediate intravenous fluid resuscitation for initial stabilization.
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Topics

Initial Stabilization and Triage

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