Critical Alerts

• Type A (ascending) is a surgical emergency - mortality 1-2% per hour without surgery
• Type B (descending) is usually managed medically unless complicated
• Control heart rate BEFORE blood pressure - beta-blockers first
• CTA is the diagnostic test of choice - high sensitivity and specificity
• Pulse deficits and neurological symptoms indicate malperfusion

Key Diagnostics

• CTA chest/abdomen/pelvis with contrast (gold standard)
• ECG (rule out MI, may show ischemic changes)
• Chest X-ray (widened mediastinum in ~60%)
• Bedside echocardiography (aortic regurgitation, pericardial effusion)
• D-dimer (<500 ng/mL has high negative predictive value)

Emergency Treatments

• Heart rate control first: Esmolol or labetalol IV
• Target HR <60 bpm, SBP 100-120 mmHg
• Then BP control: Add nitroprusside if needed
• Pain control: IV opioids
• Type A: Emergent cardiothoracic surgery
• Type B (uncomplicated): Medical management, often ICU

Aortic dissection is a tear in the intimal layer of the aorta that allows blood to enter the media, creating a false lumen. It is the most common acute aortic emergency and carries high mortality without prompt treatment.

Stanford Classification (Most Commonly Used)

DeBakey Classification

Timing Classification

Epidemiology

• Incidence: 3-4 per 100,000 per year
• Type A: ~60% of cases
• Type B: ~40% of cases
• Mortality (Type A untreated): 50% within 48 hours
• Peak age: 60-80 years; males > females

Critical Presentations

Complications of Type A Requiring Emergent Surgery

• Aortic rupture
• Cardiac tamponade
• Severe aortic regurgitation
• Coronary malperfusion
• Stroke (relative - controversial)

Complicated Type B Requiring Intervention

• Rupture or impending rupture
• Malperfusion syndrome (visceral, renal, limb)
• Rapid expansion
• Refractory pain despite BP control
• Uncontrollable hypertension

Other Causes of Severe Chest/Back Pain

Mimics to Consider

• Intramural hematoma (variant of dissection)
• Penetrating aortic ulcer (variant)
• Aortic aneurysm without dissection
• Symptomatic thoracic aneurysm

Risk Assessment (ADD-RS - Aortic Dissection Detection Risk Score)

High-Risk Conditions (1 point)

• Marfan syndrome or connective tissue disease
• Family history of aortic disease
• Known aortic valve disease
• Known thoracic aneurysm
• Prior aortic manipulation

High-Risk Pain Features (1 point)

• Abrupt onset
• Severe intensity
• Tearing or ripping quality

High-Risk Examination Features (1 point)

• Pulse or BP differential
• Focal neurological deficit + pain
• Aortic regurgitation murmur (new)
• Hypotension/shock

Score Interpretation:

• 0: Low risk (consider D-dimer)
• 1: Intermediate
• ≥2: High risk (proceed to imaging)

D-Dimer

• Useful for ruling OUT dissection in low-risk patients
• D-dimer <500 ng/mL has ~95% sensitivity
• NOT useful if positive (non-specific)
• Don't use to rule OUT if high clinical suspicion

Imaging

CTA Chest/Abdomen/Pelvis (Gold Standard)

Findings on CTA

• Intimal flap separating true and false lumen
• True lumen: Usually smaller, enhances first
• False lumen: Usually larger, may have slow flow
• Branch vessel involvement

TEE (Transesophageal Echo)

MRI

• Excellent sensitivity/specificity
• Limited availability in acute setting
• No contrast needed for some protocols

Chest X-ray

• Widened mediastinum (~60% sensitivity)
• Abnormal aortic contour
• Pleural effusion (usually left)
• Cannot exclude dissection

ECG

• Often normal or non-specific
• May show LVH (hypertension)
• May show inferior STEMI (RCA involvement in Type A)
• Critical: Don't give thrombolytics or anticoagulants until dissection excluded

Type A Dissection

• Destination: Operating room for emergent surgery
• If transfer needed: Contact cardiothoracic surgery at receiving hospital
• Transport: Ideally critical care transport
• Continue: Anti-impulse therapy during transport

Type B Dissection (Uncomplicated)

• Destination: ICU for close monitoring
• Monitoring: Continuous BP, HR, neuro checks
• Imaging: Repeat CTA if clinical change
• Disposition goal: Transition to oral medications, then floor/step-down

Type B Dissection (Complicated)

• Destination: OR or IR suite
• Coordination: Vascular surgery, interventional radiology
• May need: TEVAR, fenestration, open repair

Follow-up (All Patients)

Understanding Aortic Dissection

• A tear developed in the inner layer of your aorta
• This is a serious, life-threatening condition
• Treatment aims to prevent the tear from extending or rupturing
• Lifelong blood pressure control and monitoring are essential

After Treatment

• Take blood pressure medications exactly as prescribed
• Avoid heavy lifting and straining (increases aortic stress)
• Control blood pressure to target levels
• Attend all follow-up appointments and imaging
• Avoid stimulants (cocaine, amphetamines)

Warning Signs to Return

• Severe chest or back pain
• Shortness of breath
• Weakness or numbness (especially one side)
• Abdominal pain
• Leg pain or weakness

Genetic Counseling

• If connective tissue disorder suspected
• Family screening may be indicated
• Discuss with genetics if Marfan, Loeys-Dietz, etc.

Marfan Syndrome and Connective Tissue Disorders

• Higher risk at younger age
• May dissect at smaller aortic diameter
• Prophylactic surgery at lower threshold
• Family screening important

Pregnancy

• Highest risk in third trimester and peripartum
• Type A: Emergent surgery with fetal monitoring
• Type B: Medical management preferred
• Multidisciplinary care essential
• Epidural anesthesia considerations for delivery

Cocaine/Stimulant Use

• Acute hypertensive surge precipitates dissection
• Young patients presenting with chest pain
• May have normal aorta otherwise
• Beta-blockers traditionally controversial (unopposed alpha); labetalol preferred

Prior Aortic Surgery

• May dissect at anastomotic sites
• Type A vs B classification still applies
• Surgery more complex

Performance Indicators

Documentation Requirements

• Time of symptom onset
• Pain characteristics
• Vital signs in both arms
• Complete pulse examination
• Neurological examination
• Imaging results with type classification
• Anti-impulse therapy timing and agents
• Surgical consultation time
• Disposition and transfer details

Diagnostic Pearls

1. Sudden maximal onset pain is the classic feature
2. Check BP in both arms - differential indicates subclavian involvement
3. D-dimer negative (<500) helps rule out in low-risk patients
4. CXR cannot exclude dissection - widened mediastinum only 60% sensitive
5. Consider dissection before giving anticoagulants for suspected ACS

Treatment Pearls

1. Beta-blocker BEFORE vasodilator - prevents reflex tachycardia
2. Target HR <60, SBP 100-120 - reduce shear stress
3. Esmolol preferred - titratable, short-acting
4. Pain control is therapeutic - reduces sympathetic drive
5. Type A is ALWAYS surgical - don't delay

Disposition Pearls

1. Type A → OR emergently - 1-2% mortality per hour
2. Uncomplicated Type B → ICU for medical management
3. Complicated Type B → intervention (TEVAR or surgery)
4. Lifelong surveillance - all survivors need regular imaging
5. Transfer early if no cardiothoracic surgery available