Tearing pain to the back, with unequal pulses
Expansion
Classification
- Stanford A - involves the ascending aorta, whatever the site of the tear. About two thirds. Surgical emergency
- Stanford B - does not involve the ascending aorta. Managed medically unless complicated by rupture, malperfusion or refractory pain
“A is for ascending and for the Anaesthetist; B is for Beta blocker.”
Presentation
- Sudden, severe, tearing or ripping chest pain, classically radiating to the back, maximal at onset
- Unequal pulses or a blood pressure difference over 20 mmHg between arms
- New aortic regurgitation murmur, in proximal dissection
- Hypertension, or hypotension if there is tamponade or rupture
- Widened mediastinum on chest radiograph, though this is neither sensitive nor specific
Complications map onto the branches occluded: stroke (carotid), myocardial infarction (usually right coronary), tamponade, paraplegia (spinal arteries), renal failure, limb ischaemia and mesenteric ischaemia.
Investigation is CT angiography of the aorta, or transoesophageal echo if too unstable to move.
Management: reduce the shear force before the pressure, with an intravenous beta blocker first to target a systolic under 120 and a heart rate under 60, then a vasodilator. Giving a vasodilator alone causes reflex tachycardia and worsens the dissection.
Risk factors: hypertension, Marfan’s and Ehlers-Danlos, bicuspid valve, coarctation, pregnancy, cocaine and vasculitis.