Aorta

How many findings?
Potential complications ?
What Systemic Disease could be present?
Next step?

2. Findings and Diagnosis

40 year old female Type A dissection pericardial fluid likely blood, extending into the descending aorta  with RCA and left renal artery dissection
Ashley Davidoff thecommonvein.com (40F-Type-A-aortic-dissection) (103H)

1. How many findings?
   1 Type A dissection extending to descending aorta
   2) Pericardial effusion or hemopericardium
2. Potential complications ?
   1) Hemopericardium with tamponade
   2) Acute aortic regurgitation
   3) RCA dissection and MI
   4) Left renal artery Cekiac axiz SMA and ileofemoral vessel involvement3) What Systemic Disease could be present?
   • 1. Marfan syndrome
     2. Loeys-Dietz syndrome
     3. Ehlers-Danlos syndrome (vascular type, Type IV)
     4. Turner syndrome
     5. Bicuspid aortic valve-associated aortopathy
     6. Familial thoracic aortic aneurysm and dissection (FTAAD)

     Less common syndromes that may be considered:

     • Shprintzen-Goldberg syndrome
     • Homocystinuria
     • ACTA2-related vasculopathy

     4) Next step?

   • Immediate Priorities (Do These Simultaneously)

     1. 🚨 Call Cardiothoracic Surgery STAT

        • Type A aortic dissection = surgical emergency
        • No delays—definitive management is emergent open aortic repair

     2. EKG (Rule out MI from RCA dissection)

        • Inferior STEMI? (ST elevation in II, III, aVF → Suggests RCA involvement)
        • Low voltage or electrical alternans? (Suggests tamponade)

     3. Troponins (Assess myocardial injury)

        • Can be elevated in aortic dissection due to RCA involvement
        • Does NOT change management—surgery remains priority

     4. Emergent Bedside TTE (Echocardiogram)

        • Tamponade? (Pericardial effusion, RA/RV collapse)
        • Severe aortic regurgitation (AR)?
        • LV function? (Ischemia vs. global dysfunction)

     5. If Stable → CT Angiography (CTA) of Chest/Abdomen/Pelvis

        • Gold standard for defining extent of dissection
        • Confirms involvement of branch vessels, true vs. false lumen
        • Skip CTA if unstable—go directly to OR

     Stabilization While Awaiting OR

     • BP & HR Control (Prevent propagation of dissection)
       • Esmolol (1st-line) ± Nitroprusside (if hypertensive)
       • Goal SBP: 100-120 mmHg
       • Goal HR: < 60 BPM
     • If Tamponade → Pericardiocentesis ONLY if peri-arrest
       • Rapid decompression can worsen collapse
       • Controlled drainage in OR preferred

     🚨 Key Takeaway

     💡 “Call CT Surgery First, Everything Else Supports Surgery.”
     💡 “Dissection First, MI Second.” RCA dissection is treated surgically, not with PCI.

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   • MCQ’s

   • 1. A 55-year-old man with hypertension presents with sudden, severe chest pain radiating to the back. His BP is 180/100 mmHg, and a CT angiogram reveals an intimal tear in the ascending aorta. Which of the following best classifies this condition?

     A) Stanford Type A Aortic Dissection
     B) Stanford Type B Aortic Dissection
     C) Intramural Hematoma
     D) Aortic Aneurysm
     E) Myocardial Infarction

     ✅ Correct Answer: A) Stanford Type A Aortic Dissection

     Explanation:
     Aortic dissections are classified using the Stanford system, which categorizes them based on involvement of the ascending aorta:

     • Type A = Involves the ascending aorta, with or without descending aorta involvement.
     • Type B = Limited to the descending aorta (begins distal to the left subclavian artery).

     Since this case involves the ascending aorta, and descending aorta  it is Stanford Type A, which is a surgical emergency. Even if the dissection extends into the descending aorta, any involvement of the ascending aorta makes it Type A.

     ❌ Incorrect Answers:

     • B) Type B Dissection – Incorrect because Type B involves only the descending aorta without ascending involvement.
     • C) Intramural Hematoma – Incorrect as intramural hematoma (IMH) does not have an intimal tear, though it can evolve into a dissection.
     • D) Aortic Aneurysm – Incorrect because an aneurysm is a dilatation of the aorta, whereas a dissection involves a tear in the intima.
     • E) Myocardial Infarction – Incorrect because MI is caused by coronary artery occlusion, not an aortic tear. However, Type A dissections can extend into the coronary arteries (especially RCA), causing STEMI.

   • Question:2

     A 67-year-old man with a history of hypertension presents with sudden-onset severe chest pain radiating to the back. His BP is 180/95 mmHg. A CT angiogram of the chest shows crescent-shaped aortic wall thickening (8 mm) without contrast enhancement or an intimal flap. What is the most likely diagnosis?

     A) Stanford Type A Aortic Dissection
     B) Stanford Type B Aortic Dissection
     C) Aortic Intramural Hematoma (IMH)
     D) Aortic Aneurysm
     E) Myocardial Infarction

     ✅ Correct Answer: C) Aortic Intramural Hematoma (IMH)

     Explanation:

     • This patient has a crescent-shaped, non-enhancing thickening of the aortic wall, which is the hallmark of IMH.
     • Unlike a dissection, IMH lacks an intimal tear and false lumen, but it can progress to a full dissection or rupture.
     • The most common cause is rupture of the vasa vasorum within the aortic media.

     ❌ Incorrect Answers:

     • A) Stanford Type A Aortic Dissection – Incorrect because Type A dissections involve a clear intimal flap and a true/false lumen, which are absent here.
     • B) Stanford Type B Aortic Dissection – Incorrect because Type B dissections still require a flap and lumens, and this case lacks both.
     • D) Aortic Aneurysm – Incorrect because an aneurysm refers to dilatation of the aorta, not a localized hematoma within the wall.
     • E) Myocardial Infarction – Incorrect as MI presents with EKG changes (e.g., ST elevations, Q waves) and does not cause crescentic aortic wall thickening.

3. Key Differences Between Aortic IMH and Aortic Dissection

   Feature	Aortic Dissection	Intramural Hematoma (IMH)
   Definition	Tear in the intima allows blood to enter the media, creating a false lumen	Hemorrhage within the media without an intimal tear or false lumen
   Intimal Tear?	Present (Identified on imaging as an entry point)	Absent (No visible tear on imaging)
   False Lumen?	Present (Blood flow within the false lumen)	Absent (No blood flow, just a thickened aortic wall)
   Imaging Features on CT/TEE/MRI	– Intimal flap visible separating true and false lumen – False lumen often larger than true lumen – Contrast-enhanced flow in false lumen	– Circular or crescent-shaped aortic wall thickening (≥7 mm) – No contrast enhancement in the hematoma – No visible intimal flap
   Pathophysiology	Blood enters and propagates through a tear in the intima into the media	Vasa vasorum rupture leads to localized hemorrhage within the media
   Progression	May lead to rupture, malperfusion, or tamponade	Can progress to dissection or aneurysm, or resolve
   Management	– Type A → Emergency surgery – Type B → BP control ± TEVAR (if complicated)	– Type A IMH → Surgery – Type B IMH → Medical therapy unless complicated

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   How to Differentiate on Imaging?

   1. CT Angiography (CTA)

   • Dissection: Visible intimal flap with contrast-filled true and false lumens.
   • IMH: Uniform, crescentic aortic wall thickening (≥7 mm) with no visible flap and no contrast enhancement within the hematoma.

   2. Transesophageal Echocardiography (TEE)

   • Dissection: Intimal flap seen oscillating between lumens.
   • IMH: Thickened aortic wall without a flap.

   3. MRI

   • Dissection: Identifies true and false lumens using flow-sensitive sequences.
   • IMH: Shows high-intensity signal (subacute blood) in the aortic wall without flow.

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   Clinical Significance

   • IMH can evolve into dissection if the hematoma extends and weakens the intima.
   • Both conditions can lead to rupture, requiring close monitoring.
   • Treatment for Type A IMH is surgery, similar to Type A dissection.
   • Type B IMH is treated like Type B dissection: medically unless complicated.
     

     3. Which of the following is the most immediate life-threatening complication of an ascending aortic dissection?

     A) Aortic Aneurysm Rupture
     B) Pericardial Tamponade
     C) Stroke
     D) Mesenteric Ischemia
     E) Aortic Regurgitation

     ✅ Correct Answer: B) Pericardial Tamponade

     • Explanation: Dissections of the ascending aorta can rupture into the pericardial sac, causing tamponade—leading to rapid hypotension, shock, and death if not treated immediately.

     ❌ Incorrect Answers:

     • A) Aortic Aneurysm Rupture – Rupture can occur but is less immediate than tamponade.
     • C) Stroke – A concern if the dissection involves carotid arteries, but not the most immediate cause of death.
     • D) Mesenteric Ischemia – Occurs if the dissection involves the SMA, but tamponade kills faster.
     • E) Aortic Regurgitation – Can be severe but usually does not cause immediate collapse like tamponade.

4. Question:

   A 58-year-old man with aortic dissection rupture is brought to the emergency department in shock. His BP is 70/40 mmHg, heart sounds are muffled, and jugular venous distension is noted. Bedside echocardiography shows a moderate pericardial effusion with right atrial and right ventricular diastolic collapse. What is the most likely reason why this patient developed severe hemodynamic compromise with a relatively small pericardial effusion?

   A) Acute tamponade occurs when pericardial fluid exceeds 1,000 mL
   B) The pericardium is highly elastic and can accommodate rapid fluid accumulation
   C) The pericardium lacks time to stretch in acute tamponade, leading to rapid compression of the heart
   D) Chronic tamponade is more dangerous than acute tamponade
   E) The right ventricle can compensate for acute tamponade by increasing preload

   ✅ Correct Answer: C) The pericardium lacks time to stretch in acute tamponade, leading to rapid compression of the heart

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   Explanation:

   • In acute tamponade (e.g., from aortic dissection rupture, myocardial rupture, trauma), the fibrous pericardium does not have time to stretch.
   • Even a small volume (50-200 mL) can cause rapidly increasing pericardial pressure, leading to diastolic collapse, obstructive shock, and death if untreated.

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   ❌ Incorrect Answers:

   • A) Acute tamponade occurs when pericardial fluid exceeds 1,000 mL → Incorrect. This is true for chronic tamponade, where slow accumulation allows the pericardium to stretch.
   • B) The pericardium is highly elastic and can accommodate rapid fluid accumulation → Incorrect. The pericardium is non-elastic acutely, which is why small volumes can cause tamponade.
   • D) Chronic tamponade is more dangerous than acute tamponade → Incorrect. Acute tamponade is more dangerous because it leads to rapid cardiovascular collapse, while chronic tamponade progresses more slowly.
   • E) The right ventricle can compensate for acute tamponade by increasing preload → Incorrect. The right ventricle actually collapses in diastole due to external pressure, worsening cardiac output.

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   Key Takeaways:

   💡 Acute tamponade = Small volume (50-200 mL) → Rapid shock
   💡 Chronic tamponade = Larger volume (1,000+ mL) → Gradual symptoms
   💡 Aortic dissection rupture → One of the fastest ways to fatal tamponade

4. A patient with acute Type A aortic dissection presents with hypotension, jugular venous distension, and muffled heart sounds. What is the most appropriate next step?

A) Urgent Pericardiocentesis
B) IV Fluids and Observation
C) Call Cardiothoracic Surgery for Emergent Repair
D) Coronary Angiography
E) Thrombolysis with tPA

✅ Correct Answer: C) Call Cardiothoracic Surgery for Emergent Repair

• Explanation: This patient has Beck’s Triad (hypotension, JVD, muffled heart sounds) = Pericardial Tamponade, likely due to ruptured Type A dissection. Emergency surgery is required immediately.

❌ Incorrect Answers:

• A) Pericardiocentesis – Only done if the patient is in cardiac arrest or peri-arrest, otherwise it may worsen outcomes.
• B) IV Fluids – Can worsen tamponade by increasing pericardial pressure.
• D) Coronary Angiography – Unnecessary and delays definitive treatment.
• E) Thrombolysis – Absolutely contraindicated in dissection (can worsen bleeding and rupture).