Journal of the Louisiana State Medical Society
Figure 2: Transesophageal echocardiogram with color Doppler revealing the ventricular septal defect and left-to-right shunt. Note: LV=left ventricle; S = left-to-right shunt.
Physical exam of the patient in the ICU revealed a holo- systolic murmur. A bedside transthoracic echocardiogram revealed the presence of a VSD with left-to-right shunting of blood, but the patient remained hemodynamically stable. Because of the VSD, there was concern that liberation from positive pressure ventilationmay result in cardiopulmonary compromise; however, noting that the patient remained hemodynamically stable and that most VSDs will close spontaneously, the decisionwas made to proceedwith usual care and further evaluate the septal defect once the patient was breathing spontaneously. The patient was weaned from sedation and liberated from the mechanical ventilator per the institutional Spontaneous Awakening and Breathing Trial Protocols that were derived from previously reported data. 8 Immediately following extubation, the patient became hypoxic while receiving oxygen at 5 liters/minute by na- sal cannula. Oxygen saturation reached 89% with labored respirations, tachypnea, and tachycardia. The patient was reintubated with resumption of invasive positive-pressure ventilation, and the treating clinicians chose to proceedwith urgent repair of the VSD. A preoperative transesophageal echocardiogram (TEE) revealed an unmeasured ventricular septal defect (Figure 1) with left-to-right shunt (Figure 2). Repair of the defect was performed on hospital day four. A posteroperative TEE revealed no evidence of residual shunt following the repair. The remainder of the course was uncomplicated, and the patient was admitted to an Figure 1: Transesophageal echocardiogram revealing a ventricular septal defect. Note: LV = left ventricle; RV = right ventricle; VSD = ventricular septal defect.
inpatient rehabilitation facility. The patient was discharged three weeks later with residual blindness from anoxic brain injury sustained during his initial period of cardiac arrest. DISCUSSION There are no established criteria for detecting ventricu- lar septal defects upon physical examination. In general, physicians are trained to look for signs of cardiac injury or dysfunction. Because all initial effort is directed toward keeping the patient with cardiac trauma alive in a hectic and noisy emergency department, hearing a VSD murmur often first occurs days later. Diagnostic information can be gathered expeditiously through computed tomography and echocardiography. ECG-gated CT offers improved spatial and temporal resolution and can be helpful in detecting complications after cardiac injury. 9 Transthoracic echocar- diography can be performed in the emergency department and has demonstrated excellent reliability in patients who received penetrating cardiac injury treated with emergency thoracotomy. 10 However, echocardiography may fail to de- tect a VSD. 11 Strong suspicion of VSDs is warranted in the presence of penetrating cardiac injuries and a holosystolic murmur. In such cases, VSDs should not be ruled out based solely on a negative echocardiogram. 12 Cardiac catheteriza- tionmay offer more accurate information about the presence and size of VSDs to facilitate decision-making regarding
240 J La State Med Soc VOL 166 November/December 2014
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