It’s 3:00 AM and the ER theme song wakes you from your Trauma swivel chair nap. “County, this is CFD. We’re bringing you an 11-year-old male who was a restrained passenger involved in a head-on motor vehicle collision going 45 miles per hour. Airbags deployed, and the patient was able to self-extricate. We’ll be there in 2-3 minutes.”
On arrival, you initiate your trauma exam. Your primary survey is intact. Your secondary survey is significant for an abdominal seatbelt sign and bradycardia. An eFAST is negative for abdominal, thoracic, and pericardial fluid. You obtain an ECG (Figure 1). What is your interpretation?
Interpretation:
Rate: 48 bpm; Rhythm: sinus bradycardia; Axis: normal axis (I: pos, II: pos., aVF: pos) Intervals: PR: 163, normal; QRS: 82, normal; QT: 452, prolonged (age 1-15, normal <440) ; P-Waves: present and associated with every QRS; QRS Complex: normal, good R wave progression; ST Segment/T-waves: abnormal ST elevations and T-waves in leads V2-V4, inverted T-waves in leads III, V1
A point-of-care echocardiogram is performed without obvious regional wall motion abnormalities (RWMA) or pericardial fluid. An ECG is repeated and demonstrates the same abnormalities. The troponin level comes back unremarkable at <0.03.
What is your diagnosis? What are your next steps? What do the data say about how this patient should be managed?
Discussion:
This patient was diagnosed with blunt cardiac injury (BCI) and admitted to the Cook County PICU for telemetry monitoring and serial ECGs. During his hospital course, the patient developed occasional PVCs on telemetry and became hypotensive with systolic blood pressures ranging from 84-89 mmHg. The patient was ultimately transferred to a pediatric specialty hospital for a transthoratic echocardiogram (TTE) and transesophageal echocardiogram (TEE), as well as further evaluation by the Pediatric Cardiology service.
What constitutes BCI? How often is it seen? What do the EAST guidelines say regarding treatment of BCI? How do the data support the management of the patient in this case?
What constitutes BCI?
The term “blunt cardiac injury” refers to a range of pathologies resulting from blunt trauma to the thorax, including myocardial contusion, valvular laceration, cardiac rupture, and comotio cordis. In this case, the patient likely suffered from myocardial contusion given his presentation.
What do the EAST guidelines say regarding the treatment of BCI?
The most recent EAST guidelines for the treatment of BCI were published in 2012 and provide three levels of recommendation:
Level 1: The recommendation is convincingly justifiable based on the available scientific information alone (L1);
Level 2: The recommendation is reasonably justifiable by available scientific evidence and strongly supported by expert opinion (L2);
Level 3: The recommendation is supported by available data, but adequate scientific evidence is lacking (L3).
All patients with a traumatic mechanism concerning for BCI should receive an ECG (L1), and if a new abnormality (unknown or compared to previous ECGs) is identified, the patient should be admitted for serial ECGs (L2). All patients with a trauma mechanism concerning for BCI should have a troponin level checked. If the troponin level is elevated, the patient should receive a serial troponin level (L3). A patient with a normal ECG but an elevated troponin level should also be admitted for serial ECGs (L2) and troponin levels (L3). Hemodynamic instability or a persistent new arrhythmia should prompt obtaining an emergent echocardiogram (L2). A normal ECG and a normal troponin lvel effectively rule out BCI (L2) (1).
How does the data support the management of BCI in this case?
A review article published in 2004 demonstrated that the most common ECG abnormalities identified in patients with BCI are non-specific ECG changes such as bradycardia, frequent PACs/PVCs (50-70%), non-specific ST-T wave changes (4-42%), new Q waves (2-4%), and dysrhythmias (4-30%) (2-3). Our patient demonstrated new bradycardia with new ST-T wave abnormalities, some of the most common findings in patients with BCI.
Per the most recent EAST guidelines, this patient should also receive a troponin level, which was negative. As BCI is not reliably ruled out (+EKG, -Trop), the patient was admitted for telemetry and observation (Level 2 EAST recommendation) with serial ECGs.
There is currently no sufficient data to determine the need for serial troponin levels or the timing of these. However, the EAST guidelines do recommend trending troponin levels with ECGs (1). Notably, one study demonstrated that peak troponin levels specifically in a pediatric population did not correlate with abnormalities on echocardiography and was not useful in detecting cardiac injury (1).
The patient in this case did not become symptomatic while in the PICU, which would have been an indication for emergent echocardiography (1-3). However, he did have persistent bradycardia and hypotension with development of PVCs (hemodynamic instability, cardiac dysfunction), which is an indication for emergent echocardiography (2, 5-7), and the decision was made to obtain echocardiography (Level 2 EAST recommendation) in consultation with Pediatric Cardiology.
Take Away Points:
Order an ECG and troponin level on all patients with a mechanism or exam findings consistent with blunt cardiac injury.
Order emergent echocardiography (TEE preferred to TTE) in patients with blunt cardiac injury who demonstrate hemodynamic instability or severe dysrhythmias.
Delayed echocardiography should be performed on all patients that develop hemodynamic instability or evolving ECG changes.
An initial negative ECG and troponin level effectively rules out blunt cardiac injury.
Authored by Michael Hohl, MD'; Taylor Wahrenbrock, MD; and Ari Edelheit, MD.
References:
Clancy K, Velopulos C, Bilaniuk JW, et al. Screening for blunt cardiac injury: an Eastern Association for the Surgery of Trauma practice management guideline. J Trauma Acute Care Surg. 2012;73(5 Suppl 4):S301-S306. doi:10.1097/TA.0b013e318270193a
Schultz JM, Trunkey DD. Blunt cardiac injury. Crit Care Clin. 2004;20(1):57-70. doi:10.1016/s0749-0704(03)00092-7
El-Chami MF, Nicholson W, Helmy T. Blunt cardiac trauma. J Emerg Med. 2008;35(2):127-133. doi:10.1016/j.jemermed.2007.03.018
Sangha GS, Pepelassis D, Buffo-Sequeira I, Seabrook JA, Fraser DD. Serum troponin-I as an indicator of clinically significant myocardial injury in paediatric trauma patients. Injury. 2012;43(12):2046-2050. doi:10.1016/j.injury.2011.10.034
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Dowd MD, Krug S. Pediatric blunt cardiac injury: epidemiology, clinical features, and diagnosis. Pediatric Emergency Medicine Collaborative Research Committee: Working Group on Blunt Cardiac Injury. J Trauma. 1996;40(1):61-67. doi:10.1097/00005373-199601000-00012