Traumatic injuries to the chest wall can arise from blunt or penetrating forces. Blunt cardiac injury occurs commonly in thoracic injury approximately 20–76% of the time and is often overlooked.1 The range of presentations from an asymptomatic cardiac bruise to a severe cardiac rupture necessitates early recognition. Furthermore, the consequences can be quite serious and potentially fatal for unrecognized cardiac injuries; hence, early assessment and aggressive management can lead to improved outcomes. Ultrasound provides a useful method of evaluating cardiac trauma because it is readily available at the bedside, provides good image quality, and can be used serially to monitor the effects of interventions.
Utility of Transthoracic Echocardiography in Trauma Patients
The patient history, including an understanding of the mechanism of injury, and the physical examination remain primary methods of gathering objective information for the trauma victim. Although there are limited data to support the use of ultrasound in blunt cardiac injury, cardiac ultrasound complements the history and physical examination particularly if there is concern for anatomical irregularities, pericardial effusion, apical thrombi, or structural damage, such as cardiac contusions, concussion, muscle rupture, or valvular disruption, that would be difficult to identify through physical examination alone. Cardiac ultrasound can also help to assess hemodynamic profiles, volume status, and the cardiac index. Transthoracic echocardiogram (TTE) is warranted as a component of the focused assessment with sonography in trauma (FAST) examination and when questionable signs are encountered on the physical examination or when symptoms manifest after a traumatic injury. Table 16-1 provides a summary of the indications for echocardiography in trauma patients.2
TABLE 16-1Summary of Indications for Cardiac Ultrasonography in Traumatic Injury
One of the important contributions of cardiac ultrasound is that it has portability and is noninvasive. It can be used serially to monitor a patient over time. This is highly relevant for the hemodynamic assessment of trauma patients. In a study by Gunst et al., transthoracic ultrasonographic measures were well correlated with cardiac index and central venous pressure measurements obtained by a pulmonary artery catheter.3
Sequela After Blunt Cardiac Injury
Blunt cardiac trauma can lead to myocardial injury and manifest as wall motion abnormality ...