CT Chest with Contrast is the Most Appropriate Diagnostic Test for Suspected Aortic Dissection
CT chest with contrast is the most appropriate diagnostic test for this 59-year-old male presenting with symptoms and signs highly suggestive of acute aortic dissection.
Clinical Presentation Analysis
The patient's presentation strongly suggests aortic dissection based on several key findings:
- 59-year-old male with multiple cardiovascular risk factors (hypertension, type 2 diabetes, hyperlipidemia)
- Stabbing upper back pain for two days unresponsive to over-the-counter medications
- Severely elevated blood pressure (180/100 mmHg)
- Diastolic blowing murmur (3/6)
- S4 heart sound
- Tachycardia (HR 95)
This combination of findings—particularly the stabbing upper back pain, diastolic murmur, and severe hypertension in a patient with multiple cardiovascular risk factors—creates a high clinical suspicion for aortic pathology, specifically aortic dissection.
Diagnostic Test Selection
CT Chest with Contrast
- Primary choice for suspected aortic dissection
- Provides rapid, detailed visualization of the aorta and branch vessels
- Can identify the presence, extent, and complications of aortic dissection
- Can rule out other causes of acute chest/back pain (pulmonary embolism, pneumothorax)
- High sensitivity (>95%) and specificity (>98%) for aortic dissection 1
Echocardiogram
- While useful for assessing cardiac function and valvular abnormalities
- Less sensitive than CT for visualizing the entire aorta, particularly the descending thoracic aorta
- May miss distal dissections
- Better suited as a follow-up test after initial diagnosis 2
MRI
- Excellent for aortic imaging but impractical in emergency settings
- Time-consuming and not readily available in many emergency departments
- Contraindicated in unstable patients 2
Chest X-ray
- Limited utility for diagnosing aortic dissection
- May show widened mediastinum but has poor sensitivity
- Cannot definitively diagnose or exclude aortic dissection 2
Evidence-Based Approach
According to the American College of Physicians guidelines, patients presenting with acute back pain and concerning cardiovascular findings require immediate advanced imaging 2. The European Society of Cardiology guidelines specifically recommend CT with contrast as the first-line diagnostic test for suspected aortic dissection due to its wide availability, rapid acquisition time, and high diagnostic accuracy 2.
The diastolic murmur in this patient likely represents aortic regurgitation secondary to aortic root involvement in the dissection process. The S4 heart sound indicates decreased ventricular compliance, which can occur with acute pressure overload from severe hypertension or acute aortic pathology.
Management Considerations
After obtaining CT chest with contrast:
- Immediate blood pressure control (target SBP 100-120 mmHg)
- Pain management
- Surgical consultation if Type A dissection is confirmed
- Medical management for Type B dissection unless complications exist
Common Pitfalls to Avoid
- Delay in diagnosis: Aortic dissection has a mortality rate that increases approximately 1-2% per hour if untreated
- Misdiagnosis as acute coronary syndrome: Administering anticoagulants or thrombolytics could be catastrophic in aortic dissection
- Inadequate blood pressure control: Uncontrolled hypertension can worsen dissection
- Incomplete imaging: The entire aorta must be visualized from aortic root to iliac bifurcation
In this patient with multiple cardiovascular risk factors, severe hypertension, diastolic murmur, and stabbing upper back pain, CT chest with contrast represents the most appropriate initial diagnostic test to rapidly confirm or exclude aortic dissection and guide immediate management decisions.