A blunt cardiac injury is an injury to the heart as the result of blunt trauma, typically to the anterior chest wall. It can result in a variety of specific injuries to the heart, the most common of which is a myocardial contusion, which is a term for a bruise (contusion) to the heart after an injury. Other injuries which can result include septal defects and valvular failures. The right ventricle is thought to be most commonly affected due to its anatomic location as the most anterior surface of the heart. Myocardial contusion is not a specific diagnosis and the extent of the injury can vary greatly. Usually, there are other chest injuries seen with a myocardial contusion such as rib fractures, pneumothorax, and heart valve injury. When a myocardial contusion is suspected, consideration must be given to any other chest injuries, which will likely be determined by clinical signs, tests, and imaging. The signs and symptoms of a myocardial contusion can manifest in different ways in people which may also be masked by the other injuries. It is recommended that people with blunt chest trauma receive an electrocardiogram to determine if there are any irregularities with cardiac function. The presentation of an abnormal heart rhythm after sustaining a myocardial contusion can be delayed for up to 72 hours. Etiology The most common cause of blunt cardiac injury (BCI) is due to motor vehicle collisions. In evaluating causes for BCI, it is important to understand how the heart is situated within the thorax. It is protected to a certain degree by bony structures like the sternum, ribs and spine, thereby offering it significant protection and thus requiring substantial amounts of force to cause BCI. Motor vehicle collisions are implicated in most causes of BCI as significant deceleration can result in the heart tearing from its attachments to surrounding structures. It is important to note that there should be a high index of suspicion for BCI when evaluating injuries to the thoraco-abdominal area. Pathophysiology Possible mechanisms for BCI include direct, indirect, bidirectional, deceleration, blast, crush, concussive, or combined. A direct injury is the most common and occurs most likely near the end of diastole, during ventricular filling. Indirect injury results from increased preload on the heart secondary to spikes in venous circulation which can then lead to rupture of the heart. Bidirectional injuries are a result of compressive forces on the