Free Pocket Medicine: The Massachusetts General Hospital Handbook of Internal Medicine by Marc Sabatine Page A

p/w severe constant pain and hemorrhagic shock; ~80% mortality at 24 h
• Acute aortic syndromes (qv) • Thromboembolic ischemic events (eg, to CNS, viscera, extremities) • Compression of adjacent structures (eg, SVC, trachea, esophagus, laryngeal nerve) Follow-up ( Circ 2010;121:e266; Nat Rev Cardiol 2011;8:92; JAMA 2013;309:806)
• Expansion rate 0.1 cm/y for TAA, 0.3–0.4 cm/y for AAA • AAA: q3y if 3–3.9 cm; q6–12 mo if 4.0–5.4 cm (? q2y if 4–4.4) • TAA: 6 mo after dx to ensure stable, then annually.
• Screen for CAD, PAD and aneurysms elsewhere, esp. popliteal. About 25% of Pts w/
TAA will also have AAA, and 25% of AAA Pts will have a TAA: consider pan-Ao imaging.

ACUTE AORTIC SYNDROMES
    Definitions ( Circ 2003;108:628 & 2010;121:e266; Eur Heart J 2012;33:26)
• Aortic dissection : intimal tear → blood extravasates into Ao media (creates false lumen) • Intramural hematoma (IMH): vasa vasorum rupture → medial hemorrhage that does not communicate with aortic lumen; 6% of aortic syndromes; clinically identical to AoD
• Penetrating ulcer : atherosclerotic plaque penetrates elastic lamina → medial hemorrhage Classification (proximal twice as common as distal)
• Proximal : involves ascending Ao, regardless of origin (= Stanford A, DeBakey I & II) • Distal : involves descending Ao only, distal to L subclavian art. (= Stanford B, DeBakey III) Risk factors
• Hypertension (h/o HTN in >70% of dissections); male sex (~70%); cocaine • Connective tissue disease : Marfan (fibrillin-1): arachnodactyly, joint disloc., pectus, ectopia lentis, MVP; Ehlers-Danlos type IV (type III procollagen): translucent skin; bowel or uterine rupture; Loeys-Dietz (TGFbR) ; annuloaortic ectasia, familial AoD; PCKD
• Congenital aortic anomaly : bicuspid AoV, coarctation (eg, in Turner’s syndrome) • Aortitis (eg, Takayasu’s, GCA, Behçet’s, syphilis, now rare); pregnancy (typ. 3rd trim.) • Trauma : blunt, deceleration injury; IABP, cardiac or aortic surgery, cardiac catheterization

    Diagnostic studies ( Circ 2005;112:3802; & 2010;121:e266; Annals 2006;166:1350)
• Check bilateral BP and radial pulses for symmetry • CXR : abnl in 60–90% (↑ mediastinum, left pl effusion), but cannot be used to r/o dissection • CT : quick, noninvasive, readily available, Se ≥93% & Sp 98%; however, if& high clin. suspicion → additional studies ( 2 ⁄ 3 w/ AoD have ≥2 studies; AJC 2002;89:1235) • TEE : Se >95% prox, 80% for distal; can assess cors/peric/AI; “blind spot” behind trachea • MRI : Se & Sp >98%, but time-consuming test & not readily available • Aortography : Se ~90%, time-consuming, cannot detect IMH; can assess branch vessels • D-dimer : Se/NPV ~97%; ? <500 ng/mL to r/o dissec ( Circ 2009;119:2702); does not r/o IMH
    Treatment ( Lancet 2008;372:55; Circ 2010;121:1544; JACC 2013;61:1661)
• Initial Medical : ↓ dP/dt targeting HR ~60 & central BP 100–120 (or lowest that preserves perfusion; r/o pseudohypotension, eg, arm BP ↓ due to subclavian dissection)
first with IV b B (eg, propranolol, esmolol, labetalol) to blunt reflex ↑ HR & inotropy that would occur in response to vasodilators; verap/dilt if bB contraindic.
then ↓ SBP with IV vasodilators (eg, nitroprusside)
control pain with MSO 4 prn to blunt sympathetic response
• Proximal : surgery (root replacement); all acute ; chronic if c/b progression, AI or aneurysm • Distal : med Rx unless c/b progression, branch artery involvement → malperfusion/ ischemia, refractory HTN, refractory pain, rapid ↑ aneurysm size, rapid ↑ false lumen size. Repeat imaging: routinely (eg, 7 d, 3 wk, then q yr) & with any clinical or significant lab Δ. If complic., endovascular repair (covered stent graft to seal off entry, fenestrate flap, open occluded branch) preferred over surgery due to possible ↓ mort. (  JACC 2013;61:1661).
    Complications
• Rupture : pericardial sac → tamponade (avoid pericardiocentesis unless PEA); blood