Aortic Dissection Flashcards
What is aortic dissection?
It is defined as a condition in which there is a tear within the intimal layer of the aortic wall, allowing blood to pass between the intima and media – creating a false lumen
Which section of the aorta tends to be affected by aortic dissection?
Ascending Aorta
What is the pathophysiological consequence of aortic dissection?
The false lumen can propagate longitudinally along the aorta either anterograde, towards the iliac arteries, or retrograde, towards the aortic valve
This can cause branch occlusion and ischaemia of the affected arterial territory – leading to end-organ malperfusion
What are the two classification systems used in aortic dissection?
Stanford Classification System
DeBakey Classification System
What are the two classifications of aortic dissection using the Stanford Classification System?
Type A Aortic Dissection
Type B Aortic Dissection
What is type A aortic dissection?
It is defined as dissection involving of the ascending aorta, with or without involvement of the arch and descending aorta
What is type B aortic dissection?
It is defined as dissection involving of the descending aorta, distal to the left subclavian artery, and/or the abdominal aorta
What is more common - type A aortic dissection or type B aortic dissection?
Type A
What are the three classifications of aortic dissection using the DeBakey Classification System?
Type I Aortic Dissection
Type II Aortic Dissection
Type III Aortic Dissection
What is type I aortic dissection?
It is defined as dissection originating in the ascending aorta, which propagates to the aortic arch and variable amounts of the descending aorta
What is type II aortic dissection?
It is defined as dissection that originates and is confined to the ascending aorta
What is type III aortic dissection?
It is defined as dissection originating in the descending aorta, distal to the left subclavian artery
What are the seven risk factors of aortic dissection?
Male Gender
Middle Aged, 50 – 70 Years Old
Hypertension
Atherosclerotic Disease
Connective Tissue Disorders
Bicuspid Aortic Valve
Coarctation of The Aorta
What is the most common risk factor of aortic dissection?
Hypertension
Which two connective tissue disorders are associated with aortic dissection?
Ehler’s Danos syndrome
Marfan’s syndrome
What two genetic conditions commonly cause congenital heart defects - such as biscupid aortic valve and coarctation of the aorta?
Turner’s syndrome
Noonan’s syndrome
What are the seven clinical features of aortic dissection?
Severe Sudden Chest Pain
Interscapular Back Pain
Asymmetrical Blood Pressures
Absent Peripheral Pulses
Hypertension
Tachycardia
Aortic Regurgitation Murmur
Describe the two features of chest pain associated with aortic dissection
It is described as sharp, ripping and tearing in nature
It settles spontaneously
What asymmetrical blood pressure readings are considered significant?
> 20mmHg blood pressure difference between limbs
What are the six murmur features of aortic regurgitation?
Early-Diastolic, High Pitched, Blowing Murmur
Collapsing Pulse
Wide Pulse Pressure
Quincke’s Sign
De Musset’s Sign
Austin Flint Murmur
Which two clinical features indicate type A aortic dissection?
Weak pulses
Aortic regurgitation
What are the five investigations used to diagnose aortic dissection?
Blood Tests
ECG Scan
Chest X-Ray (CXR)
CT Angiogram of Chest, Abdomen & Pelvis (CTA-CAP)
Transoesophageal Echocardiography (TOE)
What three blood test results indicate aortic dissection?
Increased Lactate Levels
Increased Troponin Levels
Positive D-Dimer Result
What is the feature of aortic dissection on ECG scans?
Myocardial Ischaemia
This includes ST elevation in the inferior leads, new left bundle branch block, T wave inversion and Q waves
What are the five features of aortic dissection on CXR?
Widened Mediastinum > 8cm
Double/Irregular Aortic Contour
Inward Displacement of Atherosclerotic Calcification
Pleural Effusion
Haemothorax
What is the main feature of aortic dissection on CXR?
Widened Mediastinum > 8cm
What two CXR features indicate that aortic dissection rupture?
Pleural Effusion
Haemothorax
What is the gold standard investigation used to diagnose aortic dissection?
CT angiogram of the chest, abdomen & pelvis (CTA-CAP)
When is CT angiogram recommended to investigate aortic dissection?
Stable patients
How are CT angiograms used to investigate aortic dissection?
They are used to confirm diagnosis, classify disease and plan appropriate management
What are the five features of aortic dissection on CT angiogram?
False Lumen
Entry Tear
Aortic Dilatation
End-Organ Malperfusion Features
Acute Aortic Rupture Features
When is TOE recommended to investigate aortic dissection?
Unstable patients, in which CT angiograms scans are contraindicated
What are the six immediate management options of aortic dissection?
High Flow Oxygen
Two Wide-Bore IV Cannulas
IV Opiate Analgesia
Arterial Line Insertion
Central Venous Catheter Insertion
Urinary Catheter Insertion
How do we pharmacologically manage aortic dissection?
It involves the administration of cardiovascular agents that rapidly lower systolic blood pressure (100-120mmHg) and heart rate (60 -80bpm) levels
This is used to minimise the stress of the aortic dissection and limit further propagation
What are the three pharmacological management options of aortic dissection?
Beta-Blockers
Calcium Channel Blockers
Vasodilators
What is the first line pharmacological management option used in aortic dissection?
Beta-blockers
Name a beta blocker used to manage aortic dissection
IV labetalol
What is the second line pharmacological management option used in aortic dissection?
Calcium channel blockers
Name a calcium channel blocker used to manage aortic dissection
IV nicardipine
When are vasodilators used to manage aortic dissection?
They are used to control refractory hypertension
Name a vasodilator used to manage aortic dissection
IV sodium nitroprusside
What is the surgical management option of aortic dissection?
Open repair surgery
What is open repair surgery of aortic dissection?
It involves removal of the ascending aorta, with or without the aortic arch, and replacement with a synthetic graft
How do we manage type A aortic dissection?
Surgical management
However, whilst awaiting pharmacological management of blood pressure and heart rate is required
How do we manage type B aortic dissection?
Pharmacological management is usually all that is required
In complicated type B aortic dissections, in which aortic rupture develops, surgical management is considered
What are the seven complications of aortic dissection?
Aortic Regurgitation
Myocardial Ischaemia
Cardiac Tamponade
Ischaemic Stroke
Acute Limb Ischaemia
Renal Failure
Bowel Ischaemia
