Metaraminol-induced coronary vasospasm masquerading as ST-elevation myocardial infarction during general anaesthesia

Editor—Metaraminol is a peripheral vasoconstrictor used to maintain normotensive blood pressure during anaesthesia, and it has previously been linked with coronary vasospasm. 1 Anderson M.M. Gooi J. Bhagwat K. Bain C. Coronary vasospasm as an unexpected cause of intraoperative hemodynamic instability and cardiac arrest. Ann Thorac Surg. 2015; 100: 1086-1089 Google Scholar , 2 Khavandi A. Gatward J. Whitaker J. Walker P. Myocardial infarction associated with the administration of intravenous ephedrine and metaraminol for spinal-induced hypotension. Anaesthesia. 2009; 64: 563-566 Google Scholar , 3 Anderson M. Heparin/metaraminol: coronary vasospasm due to metaraminol and subsequent haemorrhage due to heparin: case report. Reactions. 2015; 1570: 103-126 Google Scholar To increase awareness of this phenomenon, we present a case of metaraminol-induced coronary vasospasm masquerading as ST-elevation myocardial infarction (STEMI) during general anaesthesia. A 65-yr-old female underwent general anaesthesia for a repeat pulmonary vein isolation procedure for atrial fibrillation. The patient provided written consent for publication of this report. She had a past uncomplicated pulmonary vein isolation 15 months prior, an indwelling dual-chamber permanent pacemaker for bradycardia, hypertension well controlled on perindopril, and no history of angina or exertional symptoms. Pulmonary vein isolation was performed while on therapeutic dabigatran 150 mg twice a day, with baseline activated clotting time (ACT) of 176 s. At procedure commencement, the patient was in an atrial-paced rhythm and not in atrial fibrillation. Pre-induction, a 20 G i.v. cannula and 20 G radial arterial line were inserted in the right arm. The patient received midazolam 2 mg i.v., and remifentanil infusion was commenced and continued throughout at 0.08 μg kg−1 min−1. Metaraminol infusion was commenced at 5 mg h−1 and continued throughout at 3–7 mg h−1. Induction of general anaesthesia was achieved with propofol 150 mg and rocuronium 100 mg i.v., and the trachea was intubated. Post-induction, dexamethasone 4 mg and ondansetron 4 mg i.v. were given for postoperative nausea and vomiting prophylaxis, and anaesthesia was maintained with end-tidal sevoflurane 1.8 vol%.