Apendisitis

Blunt Cardiac Injury
MARIE-CARMELLE ELIE, M.D.

Abstract
The diagnosis and management of blunt cardiac injury, formerly known as myocardial contusion, has challenged clinicians for decades. Caused primarily by motor vehicle collisions, significant blunt cardiac injury carries a high mortality rate. Yet no reliable diagnostic test exists to identify those patients at greatest risk for anadverse outcome. A literature search using the MEDLINE database was performed to compose a review of epidemiology, diagnostic intervention, and therapeutic approach. The results of the search indicate that, along with a high index of suspicion, utilizing a combination of electrocardiogram, troponin, and echocardiography for appropriate patients may improve the diagnosis, risk stratification anddisposition of patients sustaining blunt cardiac injury. Key Words: Myocardial contusion, myocardial concussion, myocardial rupture, blunt cardiac injury, pericardial tamponade, blunt trauma, echocardiography, pericardiocentesis, cardiogenic failure.

Introduction THE TERM “BLUNT CARDIAC INJURY” (BCI) describes a spectrum of myocardial lesions acquired from non-penetrating mechanisms. Sequelae fromthese injuries range from the benign to catastrophic. Traumatic injuries remain the fifth leading killer of Americans (1). It has been estimated that in the prehospital setting, 20% of traumatic deaths are caused by cardiac-related injuries (2). Over the past 2 decades, the improvement of prehospital transport and early implementation of advanced life support (ALS) have enabled victims of formerlynonsurvivable cardiac injuries to arrive in advance of terminal shock. A heightened level of suspicion and early identification of the blunt cardiac injury is vital. Reliable detection, however is challenging, as there are still no diagnostic criteria for blunt cardiac injury (3).
Assistant Professor, Division of Emergency Medicine, Department of Surgery and Division of Critical Care, Department ofMedicine Director of Emergency Critical Care, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, NJ. Address all correspondence to Marie-Carmelle Elie, M.D., 150 Bergen Street, M219, Newark, New Jersey 07103; email: eliema@umdnj.edu Accepted for publication July 2005.
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Nomenclature Historically, the term “myocardial contusion and concussion” wascriticized for its lack of specificity for severity and injury pattern. “Myocardial contusion” was used as a general term encompassing the gamut of myocardial injuries. The true incidence of myocardial injury is difficult to discern, since studies differ in their diagnostic criteria. The reported incidence of myocardial contusion ranges from 17 – 70% in different study populations despite similarmechanisms of injury (2, 3). The interpretation of literature using these terms remains problematic and fails to assist in the identification of patients at greatest risk. In 1992, Mattox recommended the replacement of “myocardial contusion and concussion” with “blunt cardiac injury” along with specific descriptors to provide less ambiguous identification of the injury and its sequelae (Table) (3). Thefollowing review presents an evidencebased approach to the evaluation and management of the patient who presents with blunt thoracic injury that may involve a cardiac injury. Epidemiology The Centers for Disease Control and Prevention (CDC) reports that approximately 30,000 pa© THE MOUNT SINAI JOURNAL OF MEDICINE Vol. 73 No. 2 March 2006

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BLUNT CARDIAC INJURY—ELIE

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TABLETypes of Blunt Cardiac Injury (3) Blunt Blunt Blunt Blunt Blunt Blunt cardiac cardiac cardiac cardiac cardiac cardiac injury injury injury injury injury injury with with with with with with minor ECG or enzyme abnormality complex arrhythmia coronary artery thrombosis free wall rupture septal rupture cardiac failure

Copied with permission from Mattox KL, Flint LM, Carrico CJ, et al. Blunt...