The document describes a study evaluating the "straight left heart border" (SLHB) radiological sign for detecting hemopericardium after penetrating chest trauma. The study prospectively analyzed 162 patients over 8 years, finding the SLHB sign had low sensitivity (40%) but high specificity (84%) for detecting hemopericardium identified by surgical window. While an absent SLHB does not rule out cardiac injury, its presence should alert surgeons to potential hemopericardium.

1. The Straight Left Heart Border :
A new radiological sign for detection of a
hemopericardium after penetrating chest trauma
Andrew Nicol
Sharfuddin Chowdhury
Delawir Kahn
Sorin Edu
Pradeep Navsaria
Trauma Centre
Department of Surgery
Groote Schuur Hospital and University of Cape Town
SRS 2012

2. Background
 The chest radiograph is not considered to be
particularly useful in the diagnosis of a
penetrating cardiac injury.
 At GSH Trauma Centre, the straight left heart
border, is a newly described radiological sign
associated with the presence of blood in the
pericardial sac.

3. Aim
The aim of this study was to determine the
sensitivity and specificity of the SLHB in
the diagnosis of a hemopericardium in
stable patients after penetrating chest
trauma

4. Methods
 Prospective study – 8 year period. (2001-2009).
 All patients admitted to the GSH Trauma Centre
following penetrating chest trauma who did not
have an indication for emergency surgery.
 An erect CXR was done.

5. Methods
 A true positive was the presence of a SLHB
sign on the CXR and hemopericardium found at
subxiphoid pericardial window (SPW).
 A false positive was defined as the presence of
a SLHB sign on the CXR but the SPW was
negative for blood.
A P value < 0.05 was considered to be significant.

6. Methods
Normal Chest X- ray

7. Methods

8. Results
SLHB sign SPW positive SPW negative Total
Positive 49 6 55
Negative 75 32 107
Total 124 38 162
No. of patients 162
Mean age 27.7 (r 13 – 62)
No. of patients with SLHB 55 (34%)
True positive 49
False positive 75
Sensitivity 40%
Specificity 84%
P - value 0.005 (Chi-square)

9. Conclusion
SLHB is not a very sensitive sign for the
presence of a hemopericardium (40%) .
Although the absence of a SLHB does not
exclude a cardiac injury, it is highly specific (84%)
P = 0.005
When SLHB sign is present on CXR, it should alert
the surgeon about the possibility of a
hemopericardium.