First known case was King George II on October, 25, 1760
First known case was King George II on October, 25, 1760
First successful repair by Dr. Michael DeBakey in 1955.
". . . spontaneous tear of the arterial coats is associated with atrocious pain, with symptoms, indeed, in the case of the aorta of angina pectoris and many instances have been mistaken for it"
William Osler, 1910.
Primary event is a tear in the aortic intima.
Primary event is a tear in the aortic intima.
Degeneration of aortic media, or cystic medial necrosis, is felt to be a prerequisite nontraumatic aortic dissection
Blood passes into the aortic media through the tear, separating the intima from the media and creating a false lumen.
Propagation of the dissection can occur both distal and proximal to the initial tear,
Propagation of the dissection can occur both distal and proximal to the initial tear,
Complications of dissection:
ischemia (coronary, cerebral, spinal, or visceral)
aortic regurgitation
Pericardial effusion/cardiac tamponade
DeBakey classification system
DeBakey classification system
Type I - Originates in ascending aorta, propagates at least to the aortic arch and often beyond it distally.
Type II – Originates in and is confined to the ascending aorta.
Type III – Originates in descending aorta, rarely extends proximally but will extend distally.
Daily (Stanford) classification system
Divided into 2 groups; A and B depending on whether the ascending aorta is involved.
A = Type I and II DeBakey
B = Type III DeBakey
Background
Background
Epidemiology
Clinical characteristics
Diagnostic Modalities
Treatment
Ranges from 2-10 per 100,000 person-years
Ranges from 2-10 per 100,000 person-years
Evidence of dissection is found in 1-3% of all autopsies
International Registry of Acute Aortic Dissection (IRAD)
International Registry of Acute Aortic Dissection (IRAD)
65% men
mean age 63yrs
Women tend to present older (67 vs. 60yrs)
Highest incidence in patients 50 to 70 years old.
Male-to-female ratio 2:1
Half of dissections in females before age 40 occur during pregnancy
When left untreated…
When left untreated…
33% of patients die within the first 24 hours
50% die within 48 hours
~75% die within 2-weeks
Myocardial ischemia due to an acute coronary syndrome with or without ST segment elevation
Myocardial ischemia due to an acute coronary syndrome with or without ST segment elevation
Collagen disorders (Marfan’s [50% of pts <40], Ehlers-Danlos, Pseudoxanthoma elasticum
Coarctation (Turner’s syndrome)
Family history (up to 19% of pts, # of mutations identified)
Bicuspid aortic valve
Trauma/Iatrogenic
Crack cocaine, (37% in largely AA, inner-city population study)
mean duration from last cocaine use ~12 hours. Mechanism may be abrupt, transient hypertension due to catecholamine release.
Abrupt onset of severe, sharp or "tearing" posterior chest or back pain (70-90%)
Abrupt onset of severe, sharp or "tearing" posterior chest or back pain (70-90%)
Pulse deficit
weak/absent carotid, brachial, or femoral pulse resulting from intimal flap or compression by hematoma
HTN at initial presentation is more common in those with a type B dissection (70 vs 36%)
Acute aortic insufficiency --> diastolic decrescendo murmur, hypotension, or heart failure (1/2 to 2/3 of pts)
Acute aortic insufficiency --> diastolic decrescendo murmur, hypotension, or heart failure (1/2 to 2/3 of pts)
Acute MI due to coronary occlusion (1-2%). RCA most commonly involved (L main sudden death) and, in infrequent cases, leads to complete heart block.
Tamponade
Hemothorax (if extends through adventitia)
Stroke (if involves carotids)
Horner syndrome (compression of superior cervical sympathetic ganglion) or vocal cord paralysis (compression of the left recurrent laryngeal nerve)
An analysis of 250 patients with acute chest and/or back pain (128 with a dissection) found that 96 percent of acute aortic dissections could be identified based upon some combination of the following:
An analysis of 250 patients with acute chest and/or back pain (128 with a dissection) found that 96 percent of acute aortic dissections could be identified based upon some combination of the following:
1. Abrupt onset of thoracic or abdominal pain with a sharp, tearing and/or ripping character
2. Mediastinal and/or aortic widening on chest radiograph
3. A variation in pulse (absence of a proximal extremity or carotid pulse) and/or blood pressure (>20 mmHg difference between the right and left arm)
The incidence of dissection related to the presence or absence of these three:
All three absent: 7%
Pain alone: 31%
Presence of chest radiographic abnormalities: 39%
Variation in pulse or blood pressure differential: ≥83%
Any two out of three variables: ≥83%
Background
Background
Epidemiology
Clinical characteristics
Diagnostic Modalities
Treatment
normal (31%)
normal (31%)
nonspecific ST--T wave changes (30-42%)
(commonly, LVH and strain patterns associated with HTN)
ischemic changes (15%)
acute MI (5%)
>98% do not show ST elevation
***Based on 464 IRAD patients
D-dimer ?
D-dimer ?
14-center international study of 220 patients (87 with AD, 133 controls)
Entry criteria: suspicion of AD within first 24hrs high enough to obtain imaging
D-dimer levels 3213 ±1465 and 3574 ± 1430 for type A and B respectively
Nitroprusside if HR controlled but SBP still >100mmHg
Start with β-blockers
Start with β-blockers
use of a vasodilator in isolation will actually increase aortic shear stress by widening the pulse pressure and the dP/dT of left ventricular ejection.
Blood pressure should be measured in the arm with the highest reading.
Blood pressure should be measured in the arm with the highest reading.
