Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (49 page)

   Chest x ray: abnormal in most cases (>85%) with widened mediastinum and angulation of aortic border.

   Transesophageal echocardiography: Sensitivity and specificity of 99% and 88%. Doppler may be used to discriminate true from false lumen. Cannot distinguish full arch or abdominal aorta but provides detailed information of aortic valve and pericardial involvement.

   CT: 64 slice CTA near 100% accuracy. Rapid acquisition and ED availability make CTA the first imaging choice for suspected aortic syndromes. Requires echo for detailed cardiac information.

   MRI: Superior spatial resolution improves accuracy for intramural hematomas and aortic ulcers. Provides cardiac information as well (10% of hematomas will progress to dissection, ulcer depth of >1 cm and >2 cm diameter portend worse prognosis. Small ulcers may be managed conservatively with serial imaging).

   Laboratory Findings

   
D
-dimer (by-product of fibrin degradation) is 99% sensitive for detection of dissection, but nonspecific. Elevation occurs only after dissection; hence, it is not useful as a predictor.

   Aneurysm-related mRNA signature tests show promise for detection and monitoring purposes but are not yet available for clinical use.

   It is recommended that a STAT 64 slice CT with
D
-dimer is obtained in any patient with suspected aortic dissection.

   If aortitis is noted on imaging studies, serologic evaluation for giant cell arteritis, HLA-B27, syphilis, and tuberculosis (infectious aortitis) should be performed.

Suggested Readings

Baverman AC. Acute aortic dissection: clinician update.
Circulation.
2010;122:184–188.

Hiratzka LF, Bakris GL, Beckman JA, et al. 2010 ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/ STS/SVM Guidelines for the diagnosis and management of patients with thoracic aortic disease.
J Am Coll Cardiol.
2010;55:e27–e129.

Wang YY, Barbacioru CC, Shiffman D, et al. Gene expression signature in peripheral blood detects thoracic aortic aneurysm.
PLoS One.
2007;2:e1050.

CHEST PAIN: MUSCULOSKELETAL

Potential life-threatening cardiovascular and pulmonary conditions are considered first in the evaluation of any patient with chest pain; however, there are a number of isolated chest wall syndromes and systemic conditions that may manifest as chest pain.

   Who Should Be Suspected?

   Patients whose chest pain is persistent, lasting hours to days, and is sharp and localized

   Pain that is exacerbated with movement