Blunt Cardiac Injury
VBMC TRAUMA CARE SERVICES GUIDELINE
Blunt
Cardiac Injury (BCI)
Blunt cardiac injury (BCI), formerly
called myocardial contusion, encompasses a spectrum of disease ranging from
histologic injury to the myocardium without clinical manifestation to blunt
cardiac rupture.1 BCI contributes to 20% of prehospital deaths
from blunt trauma.2 An exact incidence of BCI does not exist
because there is no “gold standard” for diagnosis, i.e., the available data are
conflicting with regard to how the diagnosis should be made (ECG,
echocardiography, enzyme analysis, etc.). This lack of a diagnostic standard
makes the literature difficult to interpret and leads to confusion in clinical
practice.
The major priority is identification
of patients at risk for adverse events resulting from BCI and providing
appropriate workup, monitoring and treatment. Patients with any significant
blunt trauma to the anterior chest should be screened. Conversely,
patients not at risk can potentially be discharged home. Patients with
appropriate mechanism of injury and clinical evidence of cardiac dysfunction
(electrophysiological or mechanical) can be considered to have BCI.
BCI results from 5 possible
mechanisms: direct pre-cordial impact, crush between sternum and spine,
deceleration or torsion causing a tear in the heart at a point of fixation,
hydraulic effect resulting in rupture from elevated intra-abdominal and caval pressure,
and blast injury.3 Few clinical signs are diagnostic of BCI.
Chest pain is the most common finding. Dyspnea, palpitations, chest wall
ecchymosis, murmur or rub, muffled heart sounds, subcutaneous emphysema and rib
fractures may also be present. Associated injuries include hemothorax, sternal
fracture and great vessel injury. Clinical signs consistent with BCI include
dysrhythmias, cardiac ischemia, low cardiac output and hypotension.4
Diagnostic tests include ECG,
echocardiography, and troponin analysis. Controversy exists regarding the
application of these tests. Frequency of diagnosis of BCI will be proportional
to the aggressiveness with which it is sought. Appropriate workup commands
achieving a balance between cost-effectiveness and information acquisition with
attention to the clinical value of information gained in changing patient
management. Guidelines for using diagnostic tests are as follows:
Level 1
An admission ECG should be
performed on all patients in whom BCI is suspected. Using any ECG
abnormality, including sinus tachycardia, bradycardia, conduction delays, and
PAC’s/PVC’s, the diagnostic sensitivity of ECG is 100%.6
Level 2
A. If
the admission ECG reveals a new abnormality (arrhythmia, ST changes, ischemia,
heart block, and unexplained ST changes), the patient should be admitted for
continuous ECG monitoring. For patients with preexisting abnormalities,
comparison should be made to a previous ECG to determine need for
monitoring.
B. In
patients with a normal ECG result and normal troponin I level, BCI is ruled
out. Patients with normal ECG but elevated troponin should be
admitted to a monitored setting.
C. For
patients with hemodynamic instability or persistent new arrhythmia, an
echocardiogram should be obtained. If transthoracic echo cannot be
performed, the patient should have a trans esophageal echo.
D. The
presence of a sternal fracture alone does not predict the presence of BCI and
should not prompt monitoring in the setting of a normal ECG and troponin.
E. CPK
with isoenzyme analysis should not be performed because it is not useful in
predicting which patients have or will have complications related to BCI.
F. Nuclear
medicine studies add little when compared with ECG and should not be routinely
performed.
Level 3
A. Elderly
patients with known cardiac disease, unstable patients, and those with an
abnormal admission ECG can safely undergo surgery provided that they are
appropriately monitored. Consider placement of a pulmonary artery
catheter in such cases.
B. Troponin
should be measured routinely for patients with suspected BCI. If
elevated, patients should be admitted to a monitored setting and troponin
should be followed serially.
C. CT or
MRI can be used to help differentiate acute myocardial infarction from BCI in
trauma patients with abnormal ECG, cardiac enzymes, and/or abnormal echo to
determine need for cardiac catheterization and/or anticoagulation.
Suspected Blunt Cardiac Injury
References:
1. Mattox KL, Flint LM, Carrico CJ,
Grover F, Meredith J, Morris J, et al. Blunt cardiac injury. J Trauma
1992;33(5):649-50.
2. Schultz
JM, Trunkey DD. Blunt cardiac injury. Crit
Care Clin 2004;20:57-70.
3. Fulda G, Brathwaite CE, Rodriguez A,
Turney SZ, Dunham CM, Cowley RA. Blunt traumatic rupture of the heart and
pericardium: a ten-year experience (1979–1989). J Trauma 1991;31(2):167-73.
4. Miller FB, Shumate CR, Richardson JD.
Myocardial contusion. When can the diagnosis be eliminated? Arch Surg
1989;124(7):805-8.
5. Pasquale NK, Clarke J. Screening of
blunt cardiac injury.1998. The Eastern Association for the Surgery of Trauma.
Available: http://www.east.org/tpg/chap2.pdf
6. Fabian TC, Cicala RS, Croce MA,
Westbrook LL, Coleman PA, Minard G, et al. A prospective evaluation of
myocardial contusion: correlation of significant arrhythmias and cardiac output
with CPK-MB measurements. J Trauma 1991;31(5):653-60.
7. Karalis DG, Victor MF, Davis GA,
McAllister MP, Covalesky VA, Ross Jr JJ, et al. The role of echocardiography in blunt chest trauma: a transthoracic and
transesophageal echocardiographic study. J Trauma 1994;36(1):53-8.
8. Fabian TC, Cicala RS, Croce MA,
Westbrook LL, Coleman PA, Minard G, et al. A prospective evaluation of
myocardial contusion: correlation of significant arrhythmias and cardiac output
with CPK-MB measurements. J Trauma 1991;31(5):653-60.
9. Salim
A, Velmahos GC, Jindal A, Chan L, Vassiliu P, Belzberg H, et al. Clinically significant blunt cardiac trauma: role of serum Troponin
levels combined with electrocardiographic findings. J Trauma 2001;50(2):237-43.
10. Collins JN, Cole FJ, Weireter LJ,
Riblet JL, Britt LD. The usefulness of serum Troponin levels in evaluating
cardiac injury [discussion]. Am Surg 2001;67(9):821-6.
11. Clancy, K.,
Velopulos, C., Bilaniuk, J., Collier, B., Crowley, W., Kurek, S…Haut, E.
(2012). Screening for blunt cardiac injury. Journal Trauma 73 (5): S301-S306.
