A tear in the intima allows blood to enter the media creating a false lumen that separates the layers of the aortic wall
Aetiology
Pathophysiology
- Intimal tear
- Blood enters media
- Formation of false lumen
- Propagation along aorta
- Complications:
- Vessel occlusion
- Aortic rupture
- Organ ischemia
Clinical Presentation
Pain (Most Important Symptom)
Characteristics
- Sudden onset
- Severe intensity (max at onset)
- “Tearing / ripping” quality
Migratory Pain (Classic Feature)
- Pain moves as dissection extends
Location & Radiation
Location | Suggests |
Anterior chest | Ascending aorta (Type A) |
Back (interscapular) | Descending aorta (Type B) |
Associated Symptoms
Cardiovascular
- Syncope due to:
- ↓ cerebral perfusion
- cardiac tamponade
- Palpitations
Respiratory
- Dyspnea
- Orthopnea (if heart failure)
Warmth & Erythema
- Local inflammation
- Skin appears:
- Red
- Warm
Neurological
- Stroke-like deficits
- Altered consciousness
- Paraplegia (spinal ischemia)
Systemic
- Anxiety
- Sweating
Physical Examination Findings
Blood Pressure Abnormalities
- Inter-arm BP difference (>20 mmHg)
- May have:
- Hypertension (common early)
- Hypotension (late, severe)
Pulse Deficits
- Weak/absent pulses (radial, femoral)
- Asymmetry between limbs
Classifications
Stanford Classification
Type | Location | Management |
Type A | Ascending ± descending | Urgent surgery |
Type B | Descending only | Medical (BP control) unless complications |
DeBakey Classificatio
Type | Description |
Type I | Originates in ascending, extends to arch & descending |
Type II | Confined to ascending aorta |
Type III | Originates in descending aorta |
Investigations
CT Angiography (CTA)
Key Findings
- Intimal flap (hallmark)
- True vs false lumen
- Extent of dissection
- Branch vessel involvement
Chest X-Ray
Findings
- Widened mediastinum (classic)
- Abnormal aortic contour
- Pleural effusion
⚠️ Not diagnostic → normal X-ray does NOT exclude dissection
Electrocardiogram (ECG)
- Often normal or nonspecific
- May show ischemic changes (if coronary arteries involved)
Important to differentiate from acute coronary syndrome
Management
Core Principle
- Rapid stabilization (reduce shear stress)
- Prevent propagation/rupture
- Definitive repair based on type (Stanford A vs B)
Initial Emergency Managementt
Hemodynamic Control (Immediate)
β-blockers — FIRST-LINE
- e.g., labetalol, esmolol
- ↓ heart rate & ↓ dP/dt (shear stress)
Add Vasodilator (if BP still high)
- e.g., nitroprusside
Only after β-blocker (avoid reflex tachycardia)
Targets
- HR < 60 bpm
- SBP 100–120 mmHg
Pain Control
- IV opioids (e.g., morphine) → reduces sympathetic drive
💊 Pharmacology
Drug Class | Examples | Mechanism | Route | Target / Monitoring | Typical Dose (Acute Setting) | Key Notes |
β-blockers (First-line) | Esmolol | β1-blockade → ↓HR, ↓contractility → ↓shear stress | IV | HR target <60 bpm, SBP 100–120 mmHg | Bolus 500–1000 mcg/kg, then 50–200 mcg/kg/min infusion | Rapid onset, short half-life |
ㅤ | Labetalol | α + β blockade → ↓HR & ↓BP | IV | Same | Bolus 20 mg, then 20–80 mg every 10 min (max 300 mg) OR infusion 0.5–2 mg/min | Useful single agent |
ㅤ | Metoprolol | β1 selective blocker | IV | Same | 5 mg IV every 5 min (up to 15 mg) | Less titratable than esmolol |
Vasodilators (Only AFTER β-blocker) | Nitroprusside | Direct arterial & venous dilation → ↓BP | IV | Continuous BP monitoring | 0.25–10 mcg/kg/min infusion | Risk of reflex tachycardia → MUST combine with β-blocker |
ㅤ | Nicardipine | Dihydropyridine CCB → arterial vasodilation | IV | BP control | 5 mg/hr infusion, increase by 2.5 mg/hr every 5–15 min (max 15 mg/hr) | Alternative to nitroprusside |
ㅤ | Clevidipine | Ultra–short-acting CCB | IV | BP control | Start 1–2 mg/hr, double every 90 sec (max ~16 mg/hr) | Rapid titration |
Non-dihydropyridine CCBs (if β-blocker contraindicated) | Diltiazem | ↓HR & contractility | IV | HR/BP | Bolus 0.25 mg/kg, then 5–15 mg/hr infusion | Use if asthma, severe β-blocker intolerance |
ㅤ | Verapamil | Same | IV | HR/BP | Bolus 5–10 mg, repeat after 15–30 min if needed | Alternative |
Analgesics | Morphine | Opioid → ↓pain & sympathetic tone | IV | Pain control | 2–4 mg IV, repeat as needed | Important to reduce catecholamine surge |
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