Aortic Dissection ✅

Related Subjects: |Assessing Chest Pain |Acute Coronary Syndrome (ACS) General |Aortic Dissection |Pulmonary Embolism |Acute Pericarditis |Diffuse Oesophageal Spasm |Gastro-oesophageal reflux |Oesophageal Perforation Rupture |Pericardial Effusion Tamponade |Pneumothorax |Tension Pneumothorax |Shingles | Ankle-Brachial pressure Index (ABPI) and Peripheral Vascular Disease | Peripheral Arterial Disease (PAD) | Abdominal Aortic Aneurysm (AAA) | Carotid Endarterectomy | Buerger's disease (Thromboangiitis obliterans ) | Leriche syndrome (aortoiliac occlusive disease)

🚨 Aortic Dissection is a life-threatening emergency caused by a tear in the aortic intima, allowing blood to enter the media and create a false lumen. Early recognition is critical: misdiagnosis as MI ❤️‍🔥 or PE 🩸 is dangerous, as anticoagulation can worsen outcomes. Urgent imaging and specialist referral are essential.

📖 Overview

• Mortality: ~40% die before reaching hospital ⚰️; an additional 10% peri/post-op.
• High-risk features: severe sudden chest/back pain, BP differences, syncope, neurologic deficits.
• Types: Stanford A (ascending aorta) and B (descending aorta), guiding management.
• NICE and ESC guidelines emphasise rapid recognition, blood pressure control, imaging, and cardiothoracic referral.

🧬 Pathophysiology

• The aortic wall has three layers: intima, media, adventitia.
• A tear in the intima allows blood under high pressure to dissect into the media → formation of a false lumen.
• Complications: rupture, tamponade, branch vessel obstruction, acute aortic regurgitation, MI, stroke.
• Extension can be antegrade (distal vessels) or retrograde (aortic valve/coronaries).
• Shear stress and hypertension exacerbate propagation; connective tissue disorders weaken the media.

🌍 Epidemiology

• Incidence: ~3–4 per 100,000/year; more common in males ♂, age >60.
• Type A: ~2/3 of cases; Type B: ~1/3.
• Risk factors: chronic hypertension, connective tissue disease (Marfan, Ehlers–Danlos), bicuspid aortic valve, pregnancy (3rd trimester), cocaine, trauma, aortitis.
• Mortality rises 1–2% per hour if Type A dissection is untreated.

🧬 Causes / Risk Factors

🫀 Classification of Thoracic Aortic Dissection

🧠 Core idea: thoracic aortic dissection is classified mainly by whether the ascending aorta is involved. This matters because ascending aortic involvement has a high risk of tamponade, acute aortic regurgitation, coronary occlusion, stroke and rupture, so it usually needs urgent surgery.

🧠 Simple Memory Aid

• 🅰️ Stanford A = Ascending aorta involved → urgent surgery.
• 🅱️ Stanford B = Beyond the left subclavian → usually medical first.
• 📍 DeBakey I and II both involve the ascending aorta, so both are Stanford A.
• 📍 DeBakey III begins in the descending aorta, so it is Stanford B.

⚠️ Complicated Type B Dissection

📌 Learning tip: In exams and acute medicine, always classify dissection first as Stanford A or B. The key question is: is the ascending aorta involved? If yes, it is Type A and the patient needs urgent cardiothoracic discussion even if they look temporarily stable.

🩺 Clinical Presentation

• Sudden severe chest/back pain: “tearing”, radiates to interscapular area ⚡🖤.
• BP asymmetry between arms >20 mmHg.
• New diastolic murmur of aortic regurgitation.
• Syncope (15%), neurological deficits, limb ischemia, abdominal pain.
• Shock or hypotension → tamponade or rupture.
• Pulsus paradoxus or absent peripheral pulses indicate major compromise.

❗ Complications

• Type A: cardiac tamponade, aortic regurgitation, MI, stroke, rupture, death 💥
• Type B: renal or mesenteric ischemia ⚠️, spinal cord ischemia 🦽, distal limb ischemia, rupture
• Chronic dissection: aneurysm formation, persistent pain, heart failure

🔎 Investigations

• Bloods: FBC, U&E, creatinine, troponin, D-dimer (helps rule out if normal).
• ECG: may mimic MI if coronary involved; usually non-specific.
• CXR: widened mediastinum, pleural effusion.
• Transthoracic echocardiography (TTE): limited, proximal ascending aorta only.
• Transoesophageal echo (TOE): bedside, rapid, sensitive for unstable patients.
• CT Aortogram (spiral CT): gold standard for diagnosis and anatomy delineation 🖥️.
• MRI: useful in chronic cases or if contrast contraindicated.

🩺 Initial Management (Acute Phase)

• ABC: oxygen, IV access, monitor vitals 💨❤️
• Pain control: IV morphine 2.5–5 mg titrated
• Blood pressure & heart rate control: IV beta-blocker (labetalol first-line), target HR ~60 bpm, systolic BP 100–120 mmHg
• Avoid anticoagulants, antiplatelets, and thrombolytics ❌
• Urgent imaging and cardiothoracic referral for Type A dissection
• Type B: medical management if uncomplicated (strict BP control, analgesia, monitoring)

🩺 Definitive Management

💊 Pharmacological Management

• IV Beta-blockers: labetalol or esmolol (reduce shear stress, HR)
• Vasodilators: nitroprusside if BP not controlled after beta-blocker
• Analgesia: IV opioids
• Avoid anticoagulation unless otherwise indicated
• Post-op: long-term antihypertensive therapy, surveillance imaging (CTA or MRI at 3, 6, 12 months)

🧪 Monitoring & Follow-up

• Continuous telemetry in acute phase
• Serial imaging: CT or MRI to monitor false lumen, aneurysm formation
• BP & HR targets lifelong: systolic 100–120 mmHg, HR 60–70 bpm
• Patient education: avoid high-intensity isometric exercise
• Genetic counseling if connective tissue disorder suspected

📚 Guidelines & NICE Compliance

• 2014 ESC Guidelines: “Acute aortic syndromes – diagnosis, imaging, and treatment”
• NICE (NG136, NG206): recommend urgent imaging for suspected dissection, avoid anticoagulation until diagnosis, early cardiothoracic referral, BP control, and long-term follow-up
• Conservative vs surgical management based on type, comorbidities, and complications
• Emphasis on structured care: ED recognition, ICU management, MDT review

🧑‍⚕️ Case Examples

• Case 1 – Type A: 58M, sudden tearing chest/back pain, unequal arm BP. ECG non-diagnostic. CT confirms ascending aorta dissection. Managed with IV labetalol, urgent surgery.
• Case 2 – Type B: 70F, interscapular back pain, hypertensive, no malperfusion. CT confirms descending dissection. Managed medically with IV antihypertensives, analgesia, monitored in ICU. TEVAR reserved for complications.
• Case 3 – Complicated: 65M, Marfan’s, chest pain, syncope, left leg weakness, hypotension. CT: Type A with branch vessel compromise. Emergency surgery + ICU care.

📊 Key Teaching Points

• Always consider dissection in acute chest/back pain, especially if tearing, radiating to back, with BP asymmetry
• Do not give anticoagulants before ruling out dissection
• Type A = surgical emergency; Type B = usually medical
• CT aortogram is gold standard; TOE useful if unstable
• Rapid BP control and pain management reduce mortality
• Follow-up imaging and lifelong BP control are essential to prevent recurrence or aneurysm formation

📚 References

• 2014 ESC Aortic Disease Guidelines
• NICE Guideline NG136: Acute chest pain assessment
• NICE Guideline NG206: Cardiac conditions emergency care
• Hiratzka LF et al., Circulation, 2010; 121: e266–369 – ACC/AHA Guidelines on Thoracic Aortic Disease