Authors: Courtney Johnson, Jessica Jahoda, Kianna Freisz, Olivia Treutline
Emergency Medicine Student Interest Group, American University of the Caribbean School of Medicine, Cupecoy, Sint Maarten
A 91 year-old female presents to the Emergency Department (ED) after being involved in a motor vehicle collision (MVC). The patient was a restrained rear seat passenger when the vehicle was rear-ended. The patient arrived at the ED complaining of pain to her neck, chest, abdomen, and left hand. Upon physical exam she was found to be tachycardic and have facial and extremity hematomas, and mild tenderness to her C-spine and periumbilical region. At the ED, the patient became hypotensive, developing hypoxia, premature ventricular contractions, and nonsustained ventricular tachycardia, which resolved with pharmacological intervention. Later the patient’s chest x-ray showed a left anterior pneumothorax with bilateral atelectasis, in which a chest tube placement was successful. Echocardiogram also showed diffuse hypokinesis, left ventricular failure, and aortic stenosis. Lab work performed revealed elevated troponin, potassium, creatinine kinase, and alcohol. The elevated troponin and creatine kinase and abnormal imaging indicates cardiac tissue involvement which could be used to determine differential diagnosis’, such as cardiac dysfunction, myocardial infarction, or cardiac tamponade. Despite the patient being successfully intubated after three attempts she eventually expired, in which the autopsy and histological examination of the myocardium confirmed the diagnosis of myocardial contusion.
While this patient eventually manifested signs of myocardial contusion, most cases are more ambiguous due to the variable clinical manifestations, absence of clear diagnostic criteria, and lack of reliable diagnostic tests. The most accurate diagnosis of a contusion can only be performed by histological examination of the myocardium. Shearing from rapid decelerations, often seen in an MVC, are the likely mechanism of injury; however, other mechanisms can include compression, abrupt pressure fluctuations, or blast injuries. While mild to moderate cases of cardiac contusion have favorable outcomes, more severe cases and trauma can lead to life threatening arrhythmias or cardiac failure. With myocardial contusions time is critical, as the life-threatening manifestations can present within the first hour and can ultimately be fatal, as shown in this case.