Visual Diagnosis in Emergency Medicine MASSIVE PULMONARY EMBOLISM WITH ACUTE CORONARY SYNDROME-LIKE ELECTROCARDIOGRAM MIMICKING ACUTE LEFT MAIN CORONARY ARTERY OBSTRUCTION Paolo Ciliberti, MD, Claudio Rapezzi, MD, Caterina Villani, MD, and Giuseppe Boriani, MD, PHD Institute of Cardiology, University of Bologna and Azienda Ospedaliera S.Orsola Malpighi, Bologna, Italy Reprint Address: Giuseppe Boriani, MD, PHD, Institute of Cardiology, University of Bologna, Policlinico S.Orsola-Malpighi, Via Massarenti 9, Bologna 40138, Italy INTRODUCTION Pulmonary embolism (PE) and acute coronary syndrome (ACS) share some clinical symptoms and features that may create difficulties in the differential diagnosis. Clinical decision-making may benefit from considerations about the value and limitations of a 12-lead electrocardiogram (ECG). CASE REPORT A 92-year-old woman with a clinical history of ischemic heart disease and prior hospitalization for paroxysmal atrial fibrillation presented to the Emergency Department (ED) due to loss of consciousness after sublingual nitro- glycerine (taken for an episode of persisting chest pain and dyspnea). Her usual medication included angiotensin-converting enzyme inhibitors and b-blockers. Aspirin had been recently withdrawn due to gastric intol- erance. An ECG performed at the patient’s home 2 h before admission recorded sinus rhythm, frequent atrial ectopic beats, and mild right intraventricular conduction delay (Figure 1). The patient’s blood pressure was 120/80 mm Hg. She was admitted to the ED of our hospital for persistent chest pain. While she was in the ED, acute Figure 1. Electrocardiogram recorded before admission showing sinus rhythm, frequent atrial ectopic beats, and mild right in- traventricular conduction delay. RECEIVED: 30 June 2010; FINAL SUBMISSION RECEIVED: 6 September 2010; ACCEPTED: 20 March 2011 e255 The Journal of Emergency Medicine, Vol. 43, No. 4, pp. e255–e258, 2012 Copyright Ó 2012 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/$ - see front matter doi:10.1016/j.jemermed.2011.03.037