By María José Bello, MD, Esther Rodríguez, MD, and Alejandro Manuel Díaz, MD
Transient cardiac arrest.
The CT scan that was acquired 70 seconds after the start of IV
contrast administration showed a contrast agent deposit with a
blood-contrast level in the dependent portion of the superior vena
cava (Figure 1A) and the inferior vena cava (Figure 1B), dense
cation of the right
portal and right hepatic veins (Figure 1C), contrast material
pooling in the right renal parenchyma (Figure 1D), and a
nonenhanced small abdominal aorta (Figure 1B, C, and D). The other
abdominal organs and vessels were unenhanced. The late-phase CT
scan, acquired 4 minutes after contrast administration, revealed
homogeneous enhancement of the abdominal organs and vessels (Figure
2) and a signiﬁ
increased abdominal aorta diameter (Figure 2C). A diagnosis of
transient cardiac arrest
was made. Seven hours later, the patient
collapsed with hypotension and cardiovascular shock. Aggressive
management (including inotropic support and ﬂ
uid resuscitation) was instituted in
the intensive care unit, and the patient temporarily revived but
remained comatose. The patient died 8 days after the CT scan.
</<span class="end-tag" />P
Burns on >
10% of the total body
surface area are responsible for systemic perturbations, which, in
cases of very severe ﬂ
volume abnormalities and electrolyte changes, can eventually lead
to burn shock, and can represent a vital risk. Removal of necrotic
tissue is a priority in treating the burn wound, but it may cause a
class="end-tag" />Sup>CT ﬁ
ndings during cardiac arrest are very
infrequently reported, and the incidence of this disorder during CT
scanning is, in fact, unknown. However, the current wide
availability of and high demand for CT scanning on seriously
injured patients has made it possible to document states of shock
or death during a CT examination. </<span class="end-tag"
>The small caliber of the aorta, the ﬂ
attened inferior vena cava, and the
decreased volume of cardiac chambers are well-known CT signs that
are associated with hypovolemic shock.<Sup
>2,3 </<span class="end-tag"
/>Sup>In this patient, a small abdominal aorta and a
attened inferior vena cava
were associated with the stasis of contrast material in the venous
system and the dependent portions of the right side of the body on
the CT images acquired 70 seconds after the start of IV contrast
administration. The pooling of contrast material in the venous
system and in the dependent parts of the right side of the body has
been described in very few previous reports, and it was suggested
that these CT ﬁ
indicative of cardiac arrest during or immediately after CT
</<span class="end-tag" />Sup>This peculiar
distribution of contrast material in severly hypotensive patients
has been attributed to the combination of the pushed pressure of
injection, the heavier hydrostatic pressure of the contrast
material, and the force of the artiﬁ
>5 </<span class="end-tag"
/>Sup>Our patient was hypotensive during the CT scan, but he
did not suffer cardiac arrest until 7 hours later. One possible
explanation for the uniform enhancement of vessels and parenchymal
organs and the signiﬁ
increased abdominal aorta diameter that were seen in our patient on
the CT scan obtained 4 minutes after contrast administration would
be the improvement of his hemodynamic status. Although vigorous
uid resuscitation is likely
needed to have a signiﬁ
effect on central venous pressure, the relatively small volume of
uid that was administered
during the CT examination probably would have made a
cant difference in the
hemodynamic status in this patient. </<span class="end-tag"
class="end-tag" />B></<span class="end-tag"
>This case illustrates that the presence of contrast
material pooling in the dependent parts of the right side of the
body in patients with serious tran</<span class="end-tag"
>sient hemodynamic abnormalities during a CT scan should
be considered a sign of transient cardiac arrest
or of the imminent
development of cardiac arrest. </<span class="end-tag" />P
>Luterman A. Burns and metabolism. J Am Coll Surg.
2000;190:104-114. </<span class="end-tag" />LI
>Shin MS, Berland LL, Ho KJ. Small aorta: CT detection
and clinical signiﬁ
Comput Assist Tomogr. 1990;14:102-103. </<span
>Rotondo A, Catalano O, Grassi R, et al. Thoracic CT
ndings at hypovolemic
shock.Acta Radiol. 1998;39:400-404. </<span class="end-tag"
>Stoger A, Munsterer B, Schinnerl A. Acute heart arrest
in spiral CT [in German]. Rofo. 2000;172:490-491. </<span
>Tsai PP, Chen JH, Huang JL, Shen WC. Dependent pooling:
A contrast-enhanced sign of cardiac arrest during CT. AJR Am J
Roentgenol. 2002;178:1095-1099. </<span class="end-tag"
>Ko SF, Ng SH, Chen MC, et al. Sudden cardiac arrest
during computed tomography examination: Clinical ﬁ
ndings and “
dense abdominal veins”
on computed tomography. J Comput
Assist Tomogr.2003; 27: 93-97. </<span class="end-tag"
>Meiner E, Rosioreanu A, Katz DS. CT ﬁ
ndings of impeding cardiac arrest.Am J
Emerg Med.2004; 22: 504-505. </<span class="end-tag"
>Roth C, Sneider M, Bogot N, et al. Dependent venous
contrast pooling and layering. A sign of imminent cardiogenic
shock. AJR Am J Roentgenol.2006;186: 1116-1119
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