Blunt cardiac injury describes a range of cardiac injury patterns resulting from blunt force trauma to the chest. Due to the multitude of potential anatomical injuries blunt force trauma can cause, the clinical manifestations may range from simple ectopic beats to fulminant cardiac failure and death. Because there is no definitive, gold-standard diagnostic test for cardiac injury, the emergency clinician must utilize an enhanced index of suspicion in the clinical setting combined with an evidence-based diagnostic testing approach in order to arrive at the diagnosis. This review focuses on the clinical cues, diagnostic testing, and clinical manifestations of blunt cardiac injury as well as best-practice management strategies.
You are working a quiet morning shift when 2 patients are brought in after a motor vehicle crash. The first patient is hypotensive, and the FAST exam reveals a pericardial effusion. You know that time is of the essence, so you rapidly assess the options and wonder whether a needle pericardiocentesis is the best option…
The second patient from the MVC has an ecchymosis across his chest. He has normal vital signs and a normal ECG, so you decide to send him for a CT to assess for thoracic and abdominal injuries. Upon returning from CT, he is tachycardic at 115 beats/min, the CT is negative, and he has a troponin of 0.0. Given that he has a seat belt sign and tachycardia, you are still concerned there may be a cardiac injury, and you wonder whether the ECG without ischemic changes and negative troponin are sufficient to exclude blunt cardiac injury. You question whether the patient needs to be admitted or observed . . . and if so, for how long?
Blunt cardiac injury (BCI) encompasses a spectrum of cardiac conditions resulting from blunt force trauma to the anterior chest wall. In 1992, Mattox used the term blunt cardiac injury to describe the spectrum of disease from a minor “bruise” to the heart to specific postcontusion cardiac conditions such as free wall rupture or myocardial hemorrhage.1 Depending upon the extent and the anatomical location of injury, the manifestations of these injury patterns range from benign ectopic beats to cardiac wall rupture resulting in sudden death. Because there are no universally accepted diagnostic criteria for the diagnosis of BCI, the true incidence is undetermined.
Motor vehicle crashes (MVCs) are the cause of most reported cases of BCI,2,3 accounting for many of the deaths related to these accidents.4-6 Failure to identify and understand the extent of blunt cardiac injuries can result in significant morbidity to the trauma patient. A high index of suspicion, application of current diagnostic protocols, and prompt and appropriate management are fundamental to maximizing good outcomes. This issue of Emergency Medicine Practice describes the most common cardiac injuries resulting from blunt trauma, the most effective diagnostic studies, and the most effective treatments for these life-threatening injuries.
PubMed was queried using the search term blunt cardiac injury. The search produced 1209 articles; however, most were case reports and reviews; large prospective trials on this topic are lacking. Additionally, this review was informed by guidelines from the Eastern Association for Surgery in Trauma (EAST). (See Table 1.)
1. “I always wait 3 hours before obtaining a troponin as part of my BCI workup.”
It would be appropriate to send troponin as part of the initial blood draw, therefore decreasing the duration of workup in the ED. Very few patients with significant BCI will have both a negative initial ECG and troponin. The important concept is to perform both tests initially, and if both are negative, then there is very little value to serial testing.
2. “The chest x-ray was normal, so I felt comfortable ruling out a pericardial effusion.”
A significant amount of fluid may be present in the pericardium despite a normal chest x-ray. If suspicion for a BCI or pericardial effusion remains, both point-of-care ultrasound and CT have high sensitivity and should be considered.
6. “For all patients with BCI, I order a formal echocardiogram and admit them to inpatient telemetry.”
Patients with suspected BCI can be effectively ruled out while in the ED or observation unit. Formal echocardiograms are reserved for patients with hemodynamic instability, persistent new dysrhythmias, and increasing troponin levels, and in symptomatic patients with significant mechanisms of injury. In otherwise stable patients, consideration of discharge home versus observation can avoid an inpatient admission.
Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, randomized, and blinded trial should carry more weight than a case report.
To help the reader judge the strength of each reference, pertinent information about the study, such as the type of study and the number of patients in the study is included in bold type following the references, where available. In addition, the most informative references cited in this paper, as determined by the author, are highlighted.
Why to Use
The FAST examination is a rapid, noninvasive, and repeatable imaging modality that can guide a surgeon in the decision to operate. It is performed in the trauma bay, and does not require patient transport out of the emergency department, which would be risky for an unstable patients.
When to Use
FAST examination results alone should not determine the decision to operate. However, a FAST examination can be a helpful adjunct for clinical decision-making, particularly in an unstable blunt trauma patient, in order to rapidly assess the chest and abdomen for potential causes of hypotension
The clinician must consider additional clinical information, including hemodynamic stability and clinical suspicion for injury.
Pericardial FAST (penetrating thoracic trauma)
Abdominal FAST (blunt abdominal trauma)
Abbreviations: CT, computed tomography; DPA, diagnostic peritoneal aspiration; TTE, transthoracic echocardiography.
Jennie Kim, MD
Morgan Schellenberg, MD, MPH
Kenji Inaba, MD, FRCSC, FACS
It can be useful to repeat the FAST examination while preparing to perform diagnostic peritoneal aspiration, in order to quickly reassess unstable patients with blunt abdominal trauma who have an initial negative FAST result. Intra-abdominal hemorrhage may not be significant enough on initial presentation to give a positive FAST result.
Clinicians should be cautious if the pericardial FAST examination is negative in a patient with penetrating thoracic trauma, especially if the patient is unstable. Cardiac injuries can decompress through the injured pericardium, most commonly into the left hemithorax, resulting in a negative pericardial FAST result (Ball 2009). Unstable patients with this mechanism of injury and a negative FAST finding should undergo a chest x-ray. If the x-ray reveals a hemothorax, a chest tube must be placed. Ongoing or high-volume chest tube output in this clinical context may be from cardiac injury.
The original study conducted by Rozycki et al in 1993 utilized the FAST examination in patients aged ≥ 16 years who had blunt or penetrating trauma (n = 476). When compared to the gold standards of computed tomography scan, diagnostic peritoneal lavage, and/or operative findings, FAST had a sensitivity of 79% and a specificity of 96%. FAST was further validated in a much larger study (n = 1540) by the same group in 1998. The validation study showed that FAST is most sensitive and specific in patients with penetrating precordial wounds (100% sensitivity, 99% specificity) and in hypotensive patients with blunt abdominal trauma (100% sensitivity, 100% specificity). Rozycki et al (1998) concluded that the accuracy of FAST in these clinical scenarios justified surgical intervention on the basis of the FAST examination findings in these trauma patients. With the application of FAST outside of study protocols by nonexperts and nonradiologists, the contemporary diagnostic yield of FAST ranges more broadly. Recent studies indicate a sensitivity of 22% to 98% for FAST in the detection of hemoperitoneum (Richards 2017, Carter 2015).
More recently, thoracic views have been added to the FAST examination, which is then termed eFAST. These windows assess the chest bilaterally for pneumothoraces and hemothoraces. In some series, the reported sensitivities of eFAST (86%- 100%) are superior to the sensitivities of chest x-ray (27%-83%) in the detection of pneumothoraces (Governatori 2015, Nandipati 2011, Wilkerson 2010).
Grace Rozycki, MD, MBA
Copyright © MDCalc • Reprinted with permission.
Eric J. Morley, MD; Bryan English, MD; David B. Cohen, MD, FACEP; William F. Paolo, MD
Jennifer Maccagnano, DO, FACOEP; Ashley Norse, MD, FACEP
March 1, 2019
March 31, 2022
Physician CME Information
Date of Original Release: March 1, 2019. Date of most recent review: February 10, 2019. Termination date: March 1, 2022.
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