In the ED, teasing out the cause of a cardiac arrest can be challenging.  Barring obvious electrographic data or a telling history of a seizure or intoxication, the ED physician must search for a cause of the arrest while stabilizing the patient.  A group from the University of Washington performed a prospective, observational trial to assess the utility of a specifically protocoled CT scan, the “sudden death CT” (SDCT).  The constituents of the SDCT include a CT head (non-contrasted), ECG gated CT of the thorax (coronary CT angiography, pulmonary artery angiography), and non-ECG gated (contrasted) CT of the abdomen and pelvis.  Over 27 months, the investigators enrolled 104 subjects.  They identified the cause of the cardiac arrest via SDCT in 43% of patients, with the remaining population having diagnoses unable to be seen on CT.  In this population, SDCT seems to be a useful tool when searching for a cause of an out-of-hospital cardiac arrest.  However, it is essential to remember that coronary CT angiography requires specialized CT scanners and trained radiologists for accurate interpretation.  Further, the patient’s heart rate needs sufficient control for quality images.  Finally, patients who have contraindications to contrasted CTs are excluded from the study population.

Reference: Branch, K. R. H. et al. Early Head to Pelvis Computed Tomography in Out‐of‐Hospital Circulatory Arrest Without Obvious Etiology. Academic Emergency Medicine (2021) doi:10.1111/acem.14228.