Nontraumatic thoracic aortic dissection
Background
2-3x > men usually 50-70 yrs old
Predisposing factors: Marfans, Ehlers-Danlos, congenital heart dz, pregnancy (third trimester), bicuspid valve (9x), cocaine, decelerating trauma, aortitis (syphilis, Takayasu, giant cell)
RISK FACTOR: Hypertension >>> smoking, cocaine, dyslipidemia
Classification
Stanford:
Type A - involves ascending Aorta, +/- descending Ao (DeBakey I & II)
Type B - distal to the origin of the L subclavian a (DeBakey III)
DeBakey:
Type I - ascending and descending Ao
Type II - isolated to ascending Ao
Type III - isolated to descending Ao
Chronic > 2wks otherwise Acute
Diagnosis
History
Pain - 90% - abrupt
VasoVagal - sweat, N\V, lt headed
Neurologic Deficit - 20-40%
Syncopy - 5-10%
Physical Exam
Tachycardia
Pulse Deficits/Discrepencies - (50% of proximal lesions but can be fleeting)
Aortic Insufficiency
Tamponade
Neuro - hemiplegia, parapesia, neuropathy
- Rare - fever unknown origin
Studies
- D-Dimer always elevated (sensitive but not specific)
ECG - Vent. hypertrophy from HTN, 10-40% may show ischemia or infarction, 33% normal
CXR - 60-90% mediastinal widening (S/S 67/70), double shadow, aortic knob, CA+ sign rare but specific, pleural effusions
Echo (TEE) (S/S 97-100/90-100)
CT & MRI - 95%
Aortography (S/S 94/88)
Treatment
Keep BP 100-120sys, HR 60-80
1. Nitroprusside (0.5-1.0mcg/kg/min; titrate) & B-blocker eg esmolol (0.5mg/kg loading, 0.05mg/kg/min infusion; titrate)
2. Labetalol (10-20mg IV q10mins, or initial infusion rate at 2mg/min; titrate) or
3. Verapamil
1. Type A - Surgery, unless worsening stroke
2. Type B - Medical, unless uncontrolled BP, Cont Pain, Rupture.
Complications
- 1 Rupture
- pericardium --> tamponade
- mediastinum --> hemothorax
- 2 Obstruction of branch vessels
- coronaries --> acute MI
- arch vessels --> stroke
- lumbar --> paraplegia
- mesenteric, renal, or limb ischemia
- 3 AV Insufficiency
- diastolic murmur and CHF
Prognosis
Uncomplicated Type B with aggressive medical therapy
-30 day mortality: 10%
-5 year mortality: 45-60%
Source
Adapted from Donaldson, Bessen, Pani, DeBonis