%0 Journal Article %T Acute Myocardial Infarction and Massive Pulmonary Embolus Presenting as Cardiac Arrest: Initial Rhythm as a Diagnostic Clue %A Nirmanmoh Bhatia %A Haree Vongooru %A Sohail Ikram %J Case Reports in Emergency Medicine %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/343918 %X Myocardial infarction (MI) and massive pulmonary embolism (MPE) are common causes of cardiac arrest. We present two cases with similar clinical presentation and EKG findings but different initial rhythms. Case£¿£¿1. A 55-year-old African American male (AAM) was brought to the emergency room (ER) with cardiac arrest and pulseless electrical activity (PEA). Twelve-lead electrocardiogram (EKG) was suggestive of ST segment elevations (STEs) in anterolateral leads. Coronary angiogram did not reveal any significant obstruction. An echocardiogram was suggestive of a pulmonary embolus (PE). Autopsy revealed a saddle PE. Case£¿£¿2. A 45-year-old AAM with a history of coronary artery disease was brought to the ER after ventricular fibrillation (VF) arrest. Twelve-lead EKG was suggestive of STE in anterior leads. Coronary angiogram revealed in-stent thrombosis. In cardiac arrests, distinguishing the two major etiologies (MI and MPE) can be challenging. PEA is more commonly associated with MPE versus MI due to near complete obstruction of pulmonary blood flow with an intact electrical conduction system. MI is more commonly associated with VF as the electrical conduction system is affected more often by ischemia. In conclusion, the previous cases illustrate that initial rhythm may be a vital diagnostic clue. 1. Background Myocardial infarction (MI) and massive pulmonary embolism (MPE) are common causes of cardiopulmonary arrest and together constitute about two-thirds of out-of-hospital arrests of no immediate apparent cause [1]. These entities may present with similar clinical features of chest pain, shortness of breath, hemodynamic instability, and cardiac arrest. Electrocardiograms (EKGs) may have striking similarities in these cases, sometimes not leading to the correct diagnosis [2, 3]. An important clue to differentiate the two could be the initial rhythm. We present two cases with similar clinical presentation and EKG changes but completely different etiology. An important diagnostic clue was the rhythm at presentation. 2. Case Presentations Case 1. A 55-year-old African American male was brought to the emergency room (ER) after a witnessed syncopal episode on the street. He was nasally intubated and resuscitated for 15 minutes after which he regained a pulse. In the ER, the patient lost his pulse again and went into pulseless electrical activity (PEA). Advanced cardiac life support (ACLS) protocol was initiated, and attempts at resuscitation were eventually successful after multiple cycles of cardiopulmonary resuscitation (CPR). A 12-lead EKG after regaining %U http://www.hindawi.com/journals/criem/2013/343918/