Cardiology > Aortic Dissection 

Background

Aortic dissection is a life-threatening condition characterized by a tear in the intimal layer of the aorta, allowing blood to enter the media and create a false lumen. This can obstruct blood flow to branch vessels or cause rupture, leading to ischemia of organs, cardiac tamponade, or death if not promptly recognized and treated. 

II) Classification/Types

By Stanford Classification (based on involvement of ascending aorta): 

• • Type A: Involves ascending aorta (± descending aorta). Surgical emergency. 

• • Type B: Involves descending aorta only (distal to left subclavian artery). Often managed medically unless complications arise. 

By DeBakey Classification: 

• • Type I: Ascending and descending aorta (originates in ascending) 

• • Type II: Ascending aorta only 

• • Type III: Descending aorta only (originates distal to left subclavian) 

By Onset: 

• • Acute: <14 days from symptom onset (higher mortality) 

• • Chronic: ≥14 days duration 

III) Pathophysiology 

Aortic dissection begins with an intimal tear due to underlying medial degeneration (e.g., cystic medial necrosis). High intraluminal pressure drives blood into the medial layer, forming a false lumen. Propagation can compress branch vessels, causing ischemia (stroke, MI, mesenteric ischemia), or rupture into the pericardium (tamponade), pleural cavity, or retroperitoneum. 

IV) Epidemiology

• • Sex: More common in men (2:1 ratio) 

• • Age: Peak incidence between 60–80 years; earlier onset in Marfan syndrome or congenital conditions 

• • Geography: Global incidence of 3–6 cases per 100,000 person-years 

• • Comorbidities: Strongly associated with hypertension, connective tissue disease, and aortic aneurysm 

Etiology

I) Causes

• • Chronic hypertension (most common) 

• • Connective tissue disorders (Marfan syndrome, Ehlers-Danlos) 

• • Bicuspid aortic valve 

• • Aortic aneurysm 

• • Aortic trauma (e.g., deceleration injury) 

• • Aortitis (e.g., syphilitic, Takayasu) 

• • Cardiac surgery or catheter-based procedures 

• • Cocaine or stimulant use 

II) Risk Factors

• • Age >60 

• • Male sex 

• • Hypertension 

• • Smoking 

• • Marfan or Ehlers-Danlos syndrome 

• • Prior cardiac/aortic surgery 

• • Family history of aortic disease 

• • Pregnancy (rare, typically third trimester or postpartum) 

Clinical Presentation

I) History (Symptoms)

• • Sudden, severe, tearing or ripping chest or back pain (most classic) 

• • Migratory pain as dissection propagates 

• • Syncope or collapse 

• • Dyspnea (if tamponade or aortic regurgitation) 

• • Neurologic symptoms (stroke, spinal cord ischemia) 

• • Abdominal or limb pain (mesenteric or limb ischemia) 

II) Physical Exam (Signs)

Vital Signs: 

• • Hypertension or hypotension (suggests rupture or tamponade) 

• • Pulse deficits or asymmetric BP (>20 mmHg difference between arms) 

• • Tachycardia 

Cardiac Exam: 

• • New diastolic murmur of aortic regurgitation 

• • Muffled heart sounds (cardiac tamponade) 

Pulmonary: 

• • Decreased breath sounds (hemothorax) 

Neurologic: 

• • Focal deficits, paraplegia, or altered mental status 

Peripheral Vascular: 

• • Absent pulses or cold limbs (limb ischemia) 

Differential Diagnosis (DDx)

• • Acute myocardial infarction 

• • Pulmonary embolism 

• • Pericardial tamponade 

• • Aortic aneurysm rupture 

• • Esophageal rupture (Boerhaave syndrome) 

• • Acute pancreatitis 

• • Spinal cord infarction 

Diagnostic Tests

Initial Tests: 

• • Chest X-ray: Widened mediastinum, pleural effusion (left-sided) 

• • ECG: May show LVH (hypertension), ischemia, or be normal 

Definitive Imaging: 

• • CT Angiography (CTA): First-line; rapid, sensitive, defines extent of dissection 

• • Transesophageal Echo (TEE): Preferred in unstable patients; bedside use 

• • MRI Angiography: Gold standard; used when stable and CTA contraindicated 

Other Tests: 

• • D-dimer: Elevated, but nonspecific; negative value may help rule out 

• • Echocardiogram (TTE): May detect aortic root dilation or tamponade 

Treatment

I) Medical Management:

Initial Goals: 

• • Reduce shear stress: Lower BP and dP/dt 

• • Target: SBP 100–120 mmHg, HR <60 bpm 

Medications: 

• • IV beta-blockers (e.g., esmolol, labetalol): First-line 

• • Add vasodilators (e.g., nicardipine, nitroprusside): If BP remains elevated after beta-blockade 

Pain control: 

• • IV opioids (e.g., morphine) to reduce sympathetic tone 

II) Surgical/Interventional Management:

Type A Dissection: 

• • Emergent surgical repair (ascending aorta replacement ± valve repair) 

• • Delay = high mortality 

Type B Dissection: 

• • Medical management unless complications (e.g., rupture, end-organ ischemia, persistent pain, refractory hypertension) 

• • Endovascular repair (TEVAR) or surgical repair if complicated 

Patient Education, Screening, Vaccines

• • Emphasize emergency response for sudden chest/back pain 

• • Adherence to antihypertensive therapy is critical 

• • Family screening for connective tissue disorders or known aortopathy 

• • Avoid high-intensity physical exertion or heavy lifting 

• • Vaccinations: 

• • Influenza annually 

• • Pneumococcal 

• • COVID-19 vaccination
    

    
    Consults

• • Cardiothoracic Surgery: Type A dissection or complicated Type B 

• • Vascular Surgery: Type B dissection with complications 

• • Cardiology: For chronic dissection monitoring and BP control 

• • Genetics: If connective tissue disorder suspected 

• • Radiology: Serial imaging and endovascular planning 

• • Primary Care/Internal Medicine: Chronic hypertension and risk factor management 

9. Follow-Up

• • Imaging: 

• • • Repeat CTA/MRA at 3, 6, and 12 months, then annually 

• • BP Monitoring: 

• • • Goal: SBP <120 mmHg, HR <60 bpm 

• • Medication Adherence: 

• • • Lifelong beta-blockers and antihypertensives 

• • Lifestyle Counseling: 

• • • Smoking cessation 

• • • Avoid heavy lifting and isometric exercises 

• • Surveillance for Aneurysm Expansion in chronic dissection