[Sternal Fracture as a Risk Factor for Blunt Cardiac Injury]

Motor vehicle collisions are the leading cause of blunt chest trauma, including blunt cardiac injury (BCI) and sternal fracture (SF). Blunt cardiac injury occurs in about 20% of blunt chest trauma reaching to 76% in polytrauma patients. Reported SF rates range from 1.6% to 42%. This review evaluates the link between SF and BCI with focus on incidence, diagnosis and implications for patient management. A systematic search of the scientific literature in online databases over the past 15 years was conducted. The final set included 31 studies, predominantly retrospective, which were subsequently analyzed with emphasis on the definition of BCI, its occurrence and its association with SF. BCI refers to a heterogeneous group of cardiac injuries resulting from a common traumatic mechanism. The term is often used interchangeably with myocardial contusion, thereby limiting the comparability of study results. Clinically significant injury can range from mild arrhythmias to cardiogenic shock, while some cases of BCI may remain completely asymptomatic. SF is common and indicates a substantial force to the chest. Patients are often categorized into two groups: those with an isolated sternal fracture, which is usually a benign injury without cardiac involvement, and those with a combined sternal fracture, which is common in polytrauma patients. The association between SF and BCI remains controversial. Some studies regard SF as a general indicator of overall trauma severity, whereas others identify it as an independent risk factor for BCI. There are multiple approaches in diagnostics of BCI. Initial screening includes electrocardiography and monitoring of troponin I levels. If both are within normal limits, BCI is unlikely. Echocardiography is recommended for hemodynamically unstable patients or when initial test results are abnormal. Management includes continuous ECG monitoring, treatment of arrhythmias and analgesia. Current recommendations support screening for BCI following blunt chest trauma. Evidence is mixed on whether SF alone predicts the presence of BCI. Further prospective studies using a uniform definition of BCI are required to confirm the clinical significance of SF in the diagnosis and patient prognosis. Physicians should maintain a high index of suspicion for BCI in patients after high-energy chest trauma.