What is the next step in evaluating a 43‑year‑old woman with sudden interscapular pain, dyspnea, headache, and dizziness after a negative chest CT angiogram for aortic dissection?

Obtain a Second Imaging Study Immediately

If high clinical suspicion exists for acute aortic dissection despite a negative chest CT angiogram, a second imaging study should be obtained using a different modality (TEE, MRI, or repeat CT). 1

Clinical Context Analysis

This 43-year-old woman presents with several high-risk features for aortic dissection that warrant continued concern despite the negative CTA 1:

• Sudden interscapular pain (classic location for dissection)
• Age under 45 years (raises concern for connective tissue disorders)
• Abrupt onset (characteristic of dissection)

Why Pursue Additional Imaging

The 2010 ACC/AHA guidelines explicitly state: "If a high clinical suspicion exists for acute aortic dissection but initial aortic imaging is negative, a second imaging study should be obtained." 1 This Class I recommendation (Level of Evidence: C) exists because:

• CT can miss dissections, particularly intramural hematomas (IMH) or thrombosed false lumens 1
• Case reports document CT-negative type A dissections that were only diagnosed at surgery 2
• Approximately 6.4% of dissections present without typical pain, and imaging can be falsely reassuring 3
• The mortality for untreated ascending dissection is 1-2% per hour 4

Recommended Imaging Sequence

Choose based on institutional availability and patient stability 1:

1. Transesophageal echocardiography (TEE) - Excellent for ascending aorta, can be done at bedside
2. Cardiac MRI - High sensitivity for IMH and subtle dissections
3. Repeat CT angiography - If technique was suboptimal or timing allows progression

Critical Pitfalls to Avoid

• Do not rely solely on negative CTA when clinical features are high-risk 1
• Do not delay for D-dimer results - while D-dimer has 94% sensitivity, false negatives occur with IMH and thrombosed false lumens 1
• Do not assume alternate diagnosis - even when other findings are present, dissection can coexist 5

Concurrent Management While Arranging Imaging

While organizing the second imaging study, initiate medical management immediately 1:

• IV beta-blockade first (target heart rate ≤60 bpm) - labetalol preferred
• Then control blood pressure (target SBP <120 mmHg) with additional vasodilators if needed
• Never give vasodilators before rate control - reflex tachycardia increases aortic wall stress 1

Additional Diagnostic Considerations

Given her headache and dizziness, specifically assess for 1, 6:

• Pulse deficits between extremities
• Blood pressure differential >20 mmHg between arms
• Focal neurologic deficits (dissection can extend to carotid arteries)
• New aortic regurgitation murmur

These examination findings would further elevate suspicion and urgency.

Bottom Line

The combination of sudden interscapular pain in a young woman with neurologic symptoms creates sufficient pretest probability that a negative CTA should not end the evaluation. Proceed directly to alternative imaging (TEE or MRI) while maintaining aggressive blood pressure and heart rate control. The stakes are too high - ascending dissection mortality approaches 50% by 48 hours without surgery 4, 3.