How can cardiac injury be excluded in the presence of stab wounds in the proximity of the heart?
Among the most lethal of all forms of trauma, cardiac injuries can present variably with hemodynamic instability, cardiovascular collapse with shock, or frank cardiac arrest. Acutely, as little as 150 ml blood can lead to tamponade. Cardiac lacerations due to penetrating trauma are associated with high morbidity and mortality. In the right clinical setting, physical exam findings, especially decreased heart sounds, distended neck veins, and hypotension (Beck’s Triad), can be diagnostic. In reality, this rarely occurs and the diagnosis of pericardial or cardiac injury must be made by diagnostic testing or surgical exploration. Surgical creation of a subxiphoid pericardial window is the gold standard for diagnosis of pericardial injury. However, because this is a highly invasive procedure with a high morbidity, it has essentially disappeared from emergency practice. While removal of 10 to 15 ml of blood can be lifesaving, it is unclear how well pericardiocentesis works in this setting, a
