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Learn about the classification, pathophysiology, incidence, risk factors, symptoms, diagnosis, and treatment of acute aortic dissection. Includes information on DeBakey classification, risk factors such as hypertension and atherosclerosis, and signs like tearing pain.
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Acute Aortic Dissection AM Report 6/29/09 Brandon M. Williams, MD
Classification • Two systems: • DeBakey • Daily (Stanford) = most used
DeBakey • Type 1: origin in ascending aorta and propagates to at least arch • Type 2: origin in ascending and confined within ascending • Type 3: origin in descending and extends (distally or proximally)
Daily (Stanford) • Type A: involves ascending aorta • Type B: all others - Nomenclature doesn’t change secondary to site of origin
Pathophysiology • Tear in aortic intima • Need degeneration of media or cystic medial necrosis for nontraumatic dissections • Blood crosses into media via tear and separates intima from media/adventitia creating a false lumen • ? If rupture of intima or hemorrhage within media causing rupture of intima is initiating event
Incidence • Acute aortic dissection - 2.6-3.5/100,000 person years
Incidence • Classic is 60 – 80 yo males (mean 63yo) • Women 67 • Ascending 2x more likely than descending, with right lateral wall most common site
Risk Factors • 13% with known aortic aneurysm (19% if < 40yo) • Inflammatory disease vasculitis -giant cell arteritis -takayasu arteritis -rheumatoid arthritis -syphilitic aortitis
Risk Factors • HTN (71%) • Atherosclerosis (31%) • DM (5.1%) • Collagen disorders (Marfan, Ehlers-Danlos) • 19% of thoracic with family history • Bicuspid aortic valve (9% < 40yo) • Aortic coarctation (post intervention) • CABG • AVR • Cardiac catheterization • Trauma • High-intensity weight lifting and cocaine via transient HTN - cocaine 37% of AA inner city population
Signs and Symptoms • Abrupt, tearing pain, back (if distal to L subclavian) or anterior (ascending) • Associated: syncope, CVA, MI, HF • Syncope assoc with worse outcome (almost all type A) • Pulse deficit • Aortic insufficiency: murmur more at RSB than valve assoc AI (LSB) • >20mmHg difference in SBP between UE • Vocal cord paralysis (compression of L laryngeal nerve) • Hypotension (hemorrhage, tamponade, HF) • Spinal cord ischemia • “STEMI:” 3/820 EKGs showing STEMI found to have ascending aortic dissection
Diagnosis • Abrupt onset of pain, tearing/ripping • Mediastinal/aortic widening on Chest X ray • Variation in pulse
Imaging • Chest Xray • TTE • TEE • CTA chest • MRI • Coronary angiography
Treatment • Involvement of ascending aorta = surgical emergency • Descending aorta: medical management unless progression or hemorrhage into pleural or retroperitoneal space -morphine -SBP 100-120 or lowest tolerated *beta blocker titrate to HR < 60 (labetalol, propranolol, esmolol) *if beta blocker intolerant: verapamil, diltiazem *no nitroprusside until HR < 60 *no hydralazine *no inotropic agents, if hypotensive look for bleeding • A-line in radial artery with highest auscultatory pressure
References • UpToDate • Management of Patients with Aortic Dissection. Weigang et al. Dtsch Arztebl Int. 2008 Sep. 105 (38) 639-645 • Conditions mimicking acute ST-segment elevation myocardial infarction in patients referred for primary percutaneous coronary intervention. Gu et at. Neth Heart Journal. 2008 Oct: 16 (10) 325-31 • Google images