When myocardial infarction is not just inferior: The importance of recognising right ventricular infarction in the prehospital setting

Introduction: Right ventricular myocardial infarction (RVMI) occurs as a consequence of an acute right coronary artery occlusion proximal to the branches supplying the right ventricular free wall. It rarely occurs as an isolated entity but presents as a complication of approximately 50% inferior myocardial infarctions. It is clinically characterised by the triad of arterial hypotension, elevated jugular venous pressure, and an absence of pulmonary congestion. In this setting, vasodilator therapy is contraindicated, while prompt intravenous volume loading represents the cornerstone of initial management. Case Presentation: A 50-year-old male presented with an acute onset of bilateral shoulder pain, nausea, and diaphoresis. The initial 12-lead electrocardiogram demonstrated an inferior STEMI, with maximal ST-segment elevation in lead III, suggestive of right coronary artery involvement. In the presence of hypotension, jugular venous distension, and clear lung fields, right-sided precordial leads were obtained, revealing ST-segment elevation in leads V4R-V6R, consistent with right ventricular involvement (Erhardt's sign). A rapid intravenous bolus of 0.9% sodium chloride was administered, resulting in hemodynamic stabilisation. The patient was urgently transferred to the cardiac catheterisation laboratory under continuous electrocardiographic and hemodynamic monitoring for primary percutaneous coronary intervention. Conclusion: Right ventricular myocardial infarction is associated with an unfavourable prognosis and carries a significant risk of iatrogenic complications if not promptly recognised. Early identification of RVMI and timely initiation of appropriate therapy are essential, especially in the prehospital setting.