Acute aortic syndromes

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

A tear or wall injury allows blood to split aortic layers, accumulate within the media or penetrate an atherosclerotic plaque. Death results from rupture, tamponade, severe acute aortic regurgitation, coronary compromise or organ malperfusion.

Risk rises with known thoracic aneurysm, hypertension, bicuspid aortic valve, coarctation, Marfan/Loeys-Dietz or other heritable aortopathy, family history, previous aortic intervention, pregnancy/postpartum state, stimulant use and major deceleration trauma.

The first minutes have two parallel objectives: confirm anatomy quickly and reduce pain, heart rate and pressure without compromising cerebral, coronary, renal or limb perfusion.

Acute type B becomes complicated with rupture or impending rupture, malperfusion, refractory pain, refractory hypertension or early expansion. These findings shift treatment from medical surveillance to intervention.

Key points

Acute aortic syndromes comprise classic dissection, intramural haematoma and penetrating atherosclerotic ulcer; each may rupture or cause branch-vessel malperfusion.
Stanford type A involves the ascending aorta; type B does not. The classification predicts the immediate treatment pathway.
Think of AAS when severe chest, back or abdominal pain is abrupt and maximal at onset, especially with a pulse/BP deficit, focal neurology, syncope, shock or new aortic regurgitation.
Normal ECG, chest radiograph, troponin or D-dimer does not safely exclude AAS when clinical probability is high.
Preferred definitive imaging is ECG-gated CTA from neck to pelvis to define the entry tear, full extent, rupture and coronary, cerebral, visceral, renal or limb malperfusion.
Begin analgesia and anti-impulse therapy in a monitored setting: typical goals are heart rate 60/min or lower and systolic BP below 120 mmHg, or the lowest pressure that maintains organ perfusion.
Control heart rate with an IV beta-blocker before adding a vasodilator; vasodilation alone may provoke reflex tachycardia and increase aortic shear.
Type A AAS requires emergency surgical assessment. Complicated type B disease generally requires urgent endovascular repair when anatomy permits; uncomplicated type B begins with optimal medical therapy and close surveillance.
Survivors need lifelong BP control and aortic imaging, commonly at 1, 6 and 12 months and then annually if stable.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Hypertension and degenerative aortic disease

Long-standing hypertension increases aortic wall stress, while aneurysmal or atherosclerotic disease weakens the wall. A penetrating aortic ulcer usually develops when atherosclerotic plaque ulcerates through the intima into the media.

Inherited and congenital aortopathy

Marfan, Loeys–Dietz and related heritable disorders impair aortic wall structure. Bicuspid aortic valve, coarctation, family history and a known thoracic aneurysm also identify people with greater susceptibility.

Procedural or traumatic injury

Previous aortic or cardiac intervention can injure the intima, while major deceleration trauma produces sudden shear forces. Either can disrupt the aortic wall and may initiate dissection.

Transient high-stress states

Pregnancy and the postpartum period alter haemodynamic and aortic-wall stress, particularly in underlying aortopathy. Cocaine or other stimulants can provoke an abrupt pressure and impulse surge.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Aortic wall disruption
Classic dissection follows an intimal tear; intramural haematoma reflects bleeding within the media, while a penetrating ulcer erodes through plaque. Each process separates or weakens aortic wall layers.
2
Longitudinal propagation
Pressurised blood tracks along the diseased media, creating a false channel or extending a haematoma. Repeated ventricular impulse and uncontrolled pressure increase shear and can drive rapid extension.
3
Branch-vessel malperfusion
The expanding false lumen can narrow a branch origin or extend directly into it. Cerebral, coronary, visceral, renal or limb blood flow then falls, sometimes fluctuating as the flap moves.
4
Proximal structural failure
Ascending-aortic involvement may distort the valve, obstruct a coronary artery or bleed into the pericardium. Acute regurgitation, myocardial infarction or tamponade can therefore dominate the presentation.
5
Rupture and exsanguination
Continued wall disruption can breach the outer aortic layer, causing haemorrhage into the pericardium, pleural space or mediastinum. The resulting shock may be rapidly fatal without definitive repair.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

High-risk painRed flag

Abrupt, severe pain maximal at onset in the chest, interscapular back or abdomen; pain may migrate as dissection extends. Painless presentations occur, especially with syncope or neurological deficit.

High-risk examinationRed flag

Pulse deficit, inter-arm pressure difference, focal neurological deficit, new early diastolic murmur, shock, tamponade, acute pulmonary oedema or signs of limb/mesenteric/renal ischaemia.

High-risk historyRed flag

Known aneurysm or aortopathy, bicuspid valve, coarctation, family history of aortic disease, recent aortic/cardiac procedure, pregnancy/postpartum state, cocaine or major deceleration injury.

Complicated type B featuresRed flag

Rupture/impending rupture, organ or limb malperfusion, persistent or recurrent pain, uncontrolled hypertension despite treatment, rapid expansion or shock require urgent aortic-team intervention.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
Immediate ABCDE assessment, both-arm BP and complete pulse/neurological examinationFirst step
Why
Identify shock, tamponade, acute AR and dynamic malperfusion while preparing definitive imaging.
Interpretation and limitations
A deficit supports AAS, but symmetrical pulses and pressures do not exclude it; repeat examinations because malperfusion can evolve.
02
12-lead ECG and continuous monitoring
Why
Detect myocardial ischaemia and guide rate-control safety.
Interpretation and limitations
A normal ECG is common; ischaemic changes may reflect coronary involvement and do not rule out AAS.
03
FBC, U&E/creatinine, LFT, coagulation, group and crossmatch, lactate, troponin
Why
Assess bleeding, renal/visceral malperfusion and operative readiness.
Interpretation and limitations
Rising lactate, creatinine or transaminases may signal malperfusion; do not delay CTA for routine results.
04
D-dimer
Why
Adjunct only in low/intermediate clinical probability within a structured diagnostic strategy.
Interpretation and limitations
A value below 500 ng/mL makes dissection less likely but cannot rule it out in high-probability disease, late presentation, intramural haematoma or thrombosed false lumen.
05
Focused transthoracic echocardiography
Why
Rapidly assess pericardial effusion/tamponade, LV function, acute AR, aortic-root size and occasionally a flap.
Interpretation and limitations
Useful at the bedside but a negative TTE does not exclude distal or even proximal disease.
06
ECG-gated CT angiography from neck to pelvisPreferred
Why
Preferred rapid anatomical test in most suspected AAS.
Interpretation and limitations
Define Stanford type, entry tear, branch involvement, rupture and malperfusion; include access-vessel anatomy for intervention.
07
Transoesophageal echo or cardiovascular MRI
Why
TOE is an alternative when haemodynamic instability prevents CT transfer; CMR is an alternative in stable patients when CT is unsuitable and delay is acceptable.
Interpretation and limitations
Choice depends on immediate availability and expertise; neither should create a harmful delay.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Acute coronary syndrome

Myocardial ischaemia more often produces pressure-like pain with evolving regional ECG and troponin changes. However, coronary malperfusion from dissection can mimic infarction, so abrupt maximal pain or pulse deficits remain important.

Pulmonary embolism

Pleuritic pain, hypoxaemia, venous thromboembolic risk and right-heart strain favour pulmonary embolism. A pulse deficit, new aortic regurgitation or migrating pain points instead towards aortic disease.

Acute pericarditis

Sharp pain relieved by sitting forward, a pericardial rub and diffuse rather than regional ECG change support pericarditis. Tamponade physiology can occur in either condition, so aortic imaging may still be required.

Oesophageal rupture

Severe chest pain following forceful vomiting, subcutaneous emphysema, pneumomediastinum or early sepsis suggests oesophageal rupture. Pulse deficits, focal neurology, a new aortic-regurgitation murmur or other malperfusion instead favour an acute aortic syndrome, but their absence does not exclude it.

Tension pneumothorax

Sudden pleuritic pain, unilateral absent breath sounds and obstructive shock favour tension pneumothorax and require immediate decompression on clinical grounds. Preserved bilateral breath sounds with a pulse deficit, new aortic-regurgitation murmur or malperfusion instead raise concern for an acute aortic syndrome, although none is required.

Additional chapter-specific clues

Alternative diagnoses do not exclude AASRed flag

ST changes, troponin elevation, stroke signs or abdominal findings can result from dissection. Thrombolysis or antithrombotic escalation before considering AAS may be catastrophic.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01Immediate / protocol-dependentSuspected AAS before anatomy is knownFirst stepCredible high-risk pain, history or examination feature.

1Activate emergency, aortic/cardiothoracic, anaesthetic and critical-care pathways; use two large-bore IVs, continuous ECG, oxygen saturation and frequent BP, with an arterial line when expertise is available.
2Give titrated IV opioid analgesia and obtain urgent ECG-gated CTA neck-to-pelvis; use bedside TOE if too unstable for CT. Inform the receiving aortic centre early and do not delay transfer for nonessential tests.
3Start IV beta-blockade if haemodynamics permit. Target heart rate 60/min or lower, then systolic BP below 120 mmHg or the lowest pressure maintaining organ perfusion.
4If BP remains above target after rate control, add a titratable IV vasodilator such as nicardipine. Do not start a vasodilator before controlling tachycardia.
5If shock is present, search immediately for rupture, tamponade, severe AR or malperfusion; avoid reflexively lowering BP and expedite operative control.

02Preferred interventionStanford type APreferredAny acute syndrome involving the ascending aorta, including dissection or intramural haematoma.

1DefinitiveContinue analgesia and carefully titrated anti-impulse therapy only while arranging emergency surgery; medical treatment is a bridge, not definitive care.
2Correct major coagulopathy and prepare blood products without delaying theatre. Coronary, cerebral and visceral malperfusion require a multidisciplinary operative strategy.
3DefinitivePericardiocentesis for tamponade is generally avoided before definitive repair because full decompression can precipitate fatal bleeding; any controlled drainage is an aortic-surgeon decision.

03Preferred / escalationStanford type BPreferredEscalationAAS confined to the descending aorta.

1Uncomplicated: admit to a monitored specialist setting for optimal anti-impulse therapy, serial examination, renal/lactate monitoring and interval imaging.
2PreferredComplicated and anatomically suitable: urgent thoracic endovascular aortic repair is preferred. Complications include rupture, malperfusion, refractory pain or hypertension and expansion.
3If anatomy is unsuitable for TEVAR, the aortic team considers open or hybrid repair. High-risk uncomplicated anatomy may justify planned subacute TEVAR after multidisciplinary review.

04Long-termAfter AAS repair or medical treatmentSurvival to discharge.

1Continue strict BP control, usually with a beta-blocker foundation if tolerated, and modify smoking and atherosclerotic risk.
2Arrange aortic-centre follow-up and cross-sectional imaging at about 1, 6 and 12 months, then annually when stable; an additional scan within 3 months may be selected by anatomy/procedure.
3Assess the entire aorta, residual false lumen, graft/stent integrity and branch vessels; refer for genetic evaluation when age, phenotype or family history suggests heritable thoracic aortic disease.

Key medicines and prescribing safety4 treatments · regimens, roles and cautions

ESC 2024 anti-impulse option when tachycardia and hypertension are present because it blocks alpha and beta receptors; use in monitored critical care.

Labetalol IV

50 mg IV over at least 1 minute, often over 1–2 minutes; repeat after 5 minutes if necessary to a usual maximum cumulative 200 mg. A specialist infusion around 15–20 mg/hour may be titrated to target.

Avoid or seek senior advice with cardiogenic shock, severe bradycardia, second/third-degree block, decompensated heart failure or active bronchospasm. Severe acute AR and borderline perfusion demand specialist titration.

ESC 2024 short-acting beta-1 blocker alternative when rapid reversibility is valuable; use in monitored critical care.

Esmolol IV

500 micrograms/kg/min for 1 minute, then 50 micrograms/kg/min for 4 minutes; if needed repeat the loading dose and increase maintenance stepwise to 100, 150 then 200 micrograms/kg/min at 5-minute intervals.

Critical-care use only; bradycardia, block, shock and decompensated heart failure. AAS use and loading strategy should follow the aortic/critical-care protocol.

ESC 2024 option for persistent hypertension only after heart-rate control, or when a beta-blocker strategy is unsuitable under specialist direction.

Nicardipine IV

Start 3–5 mg/hour for 15 minutes, then increase by 0.5–1 mg/hour every 15 minutes to a maximum 15 mg/hour; usual maintenance 2–4 mg/hour after target is reached.

Can cause hypotension and reflex tachycardia; use invasive or very frequent BP monitoring. Exercise caution with heart failure, severe aortic stenosis and hepatic/renal impairment.

Analgesia to reduce sympathetic drive while definitive imaging and treatment proceed.

Morphine sulfate IV

Give small slow IV aliquots, typically 2.5–5 mg, reassessing pain, respiratory rate and BP every 5 minutes; the SmPC adult IV range is 2.5–15 mg given over 4–5 minutes and must be individually titrated.

Respiratory depression, hypotension, reduced consciousness and renal impairment; have monitoring and reversal capability, and do not mask deterioration or delay imaging.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Aortic rupture

Full-thickness failure causes major internal haemorrhage and profound shock. A falling pressure in suspected aortic disease should prompt concern for rupture rather than reassurance that hypertension has resolved.

Cardiac tamponade

Proximal rupture into the pericardial space compresses the heart, restricting filling and causing obstructive shock. Further blood-pressure reduction may worsen perfusion while urgent surgical control is arranged.

Acute aortic regurgitation

Disruption of the aortic root or valve support permits sudden severe regurgitation. Left-ventricular filling pressure rises quickly, producing pulmonary oedema, hypotension and a need for emergency surgical assessment.

Coronary and cerebral malperfusion

Extension into coronary or arch vessels may cause myocardial infarction, syncope or stroke. These features may dominate and classic pain or pulse findings may be absent, so the wider aortic context should still be considered.

Visceral, renal or limb ischaemia

Branch-vessel obstruction can infarct bowel, impair renal function or threaten a limb. Rising lactate or creatinine, abdominal pain or new peripheral neurological deficits should raise concern for evolving malperfusion and complicated disease requiring urgent intervention.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

Continuous ECG, oxygen saturation and neurological/limb observations; arterial-line BP during IV anti-impulse therapy when feasible.
Track urine output, creatinine, lactate, acid-base status, haemoglobin and evolving abdominal or limb findings for dynamic malperfusion or rupture.
During titration, target HR 60/min or lower and SBP below 120 mmHg only if organ perfusion remains adequate; targets are syndrome- and patient-dependent.
Reassess pain: recurrent or refractory pain despite treatment is a complication and an intervention trigger, not simply an analgesic problem.
After discharge, lifelong BP review and serial whole-aorta cross-sectional imaging are essential even after technically successful repair.
Monitor beta-blockers for bradycardia, block, bronchospasm and low-output state; monitor vasodilators for reflex tachycardia and hypotension.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Rate before pressure

An arterial vasodilator can lower the number while increasing reflex tachycardia and dP/dt; beta-block the impulse first unless contraindicated.

A normal test can mislead

Normal pulses, chest radiograph or D-dimer never overrides a high-probability story. CTA is the decisive test in most stable patients.

Stroke can be aortic

Dissection may occlude arch vessels. Check pulses and consider AAS before thrombolysis when stroke accompanies abrupt chest/back pain, hypotension or a new AR murmur.

Type B is not automatically benign

Pain that will not settle, rising creatinine/lactate, limb findings or uncontrolled BP converts an apparently distal dissection into complicated disease needing urgent intervention.

The aorta remains diseased

Repair treats the immediate lesion, not the lifelong tendency to dilate, dissect or develop stent/graft complications.

11Common pitfallsFrequent interpretation and management errors.

01
Using D-dimer as a stand-alone rule-out test in a high-probability presentation.
02
Scanning only the chest and missing cerebral, visceral, renal or access-vessel involvement.
03
Giving a vasodilator before heart-rate control.
04
Treating shock with further BP lowering rather than seeking rupture, tamponade, severe AR or malperfusion.
05
Calling all type B dissections uncomplicated despite persistent pain, hypertension or organ injury.
06
Delaying aortic-centre contact until after every laboratory result is available.