Myocardial contusion as a result of isolated sternal fractures: a fact or a myth?

Isolated sternal fractures are seen with an increasing frequency in traffic road accidents especially after the introduction of the seatbelt legislation. In most cases, the victims are young, otherwise healthy individuals. The medical records of all patients who were treated with a diagnosis of sternal fracture over the past 10 years were retrospectively reviewed. All patients with a radiologic diagnosis of sternal fracture were admitted for cardiac monitoring for at least 24 hours. ECG, determinations of cardiac enzyme levels CK (creatinephosphokinase) and CK-MB and evaluation by a cardiologist were routinely performed. An echocardiography was performed when indicated by the cardiologist. A total of 86 patients had sustained a sternal fracture during the 10-year study period. There were 39 males and 47 females with a mean age of 50 years (range 15-97 years). Serial 12-lead electrocardiograms, which were performed in 83 (97%) patients, revealed no information about myocardial contusion or cardiac arrhythmias with consequent therapy. In eight patients, a significant elevation in cardiac enzyme levels (elevation of CK-MB fraction above 10% of CK) was observed. All were normalized within 24 hours without development of any arrhythmias. Echocardiography was performed in 31 patients. In two patients, dyskinesia of the right ventricle (without enzyme elevations or arrhythmias) was observed. Within 24 hours these abnormalities resolved. The cardiac rhythm was monitored in 61 (71%) patients for a total of 1550 hours. No arrhythmias were observed. The cardiac enzyme studies, ECG and echocardiography revealed no consequent information about arrhythmias. In case of a sternal fracture, we recommend a chest X-ray to exclude other associated intrathoracic injuries. If no abnormalities are identified, admission to hospital is not necessary.