AKT · Acute care/Cardiac & respiratory

Aortic dissection

Tear in the aortic intima → blood tracks within the media (false lumen)

Overview

A tear in the aortic intima lets blood track into the media, splitting the wall. A time-critical emergency: Stanford type A (ascending aorta) is surgical; type B (descending) is usually medical. The classic picture is sudden TEARING chest pain radiating to the BACK with a pulse/blood-pressure differential between the arms.

Recognise

Sudden, severe, TEARING/ripping chest or interscapular (back) pain, maximal at onset
Blood-pressure or pulse DIFFERENTIAL between the two arms; a new early-diastolic murmur (aortic regurgitation) in type A
Complications by the branch involved: stroke (carotid), MI (coronary), tamponade, paraplegia (spinal), limb/renal/mesenteric ischaemia; risk factors — hypertension, Marfan/connective-tissue disease, bicuspid valve, pregnancy

Red flags

Hypotension/tamponade, neurological deficit, or a widened mediastinum on chest X-ray → immediate imaging and cardiothoracic referral; do NOT thrombolyse (it is not an MI)

Differentials & how to tell them apart

Acute coronary syndromepressure/heavy pain without the tearing-to-back quality or BP differential — but dissection can occlude a coronary and mimic MI; thrombolysis in an unrecognised dissection is catastrophic

Pulmonary embolismpleuritic pain, hypoxia, risk factors — CTPA

Pericarditispleuritic pain relieved by sitting forward, diffuse ST elevation

Oesophageal ruptureafter vomiting, mediastinitis, surgical emphysema

Investigations

ECG (may mimic/cause MI — exclude STEMI), chest X-ray (widened mediastinum), and urgent CT ANGIOGRAM aorta (the definitive test; TOE if too unstable to move). Crossmatch; assess both arms' BP.

Management

Control BP/HR with IV beta-blocker + analgesia → urgent CT angiogram + cardiothoracic referral

1Resuscitate; rapid BP and heart-rate control with an IV beta-blocker (e.g. labetalol) and opioid analgesia; urgent CT angiogram of the aorta and immediate cardiothoracic/vascular referral.Gate: Type A (ascending) dissection is a SURGICAL emergency (emergency repair); type B (descending) is usually managed MEDICALLY with strict BP/HR control — the location decides surgery vs medicine; and never thrombolyse chest pain with a BP differential/widened mediastinum
2Type A → emergency surgery; type B → blood-pressure control in HDU/ICU, surgery/stenting only for complications (malperfusion, rupture, refractory pain); lifelong antihypertensives + surveillance imaging.

IV beta-blocker (e.g. labetalol) — first-line to lower heart rate and blood pressure (reduce aortic wall stress); target a low systolic BP/HR

Analgesia (opioid) — pain control also reduces sympathetic drive

(Avoid thrombolysis/anticoagulation) — they are dangerous if this is a dissection, not an MI

Key points

Tearing pain to the back + inter-arm BP differential + widened mediastinum = dissection. Type A = surgery, type B = medical. The lethal trap is treating it as an MI and giving thrombolysis. (Cardiovascular Tier-2 too — cross-reference.)

Monitor & prognosis

BP/HR targets, end-organ perfusion (neuro, renal, limbs), serial imaging.

Type A has very high untreated mortality (hourly) — surgery is lifesaving; type B better if uncomplicated.

Source: Resuscitation Council UK / acute care; vascular guidance