Aortic Dissection Clinical Presentation, Diagnosis and Medical Management Adoracion N. Abad, M.D.

Aortic Dissection

Clinical Presentation, Diagnosis and Medical Management

Adoracion N. Abad, M.D.

Aortic Dissection

• not very common, but challenging, frequently fatal, emergency clinical condition

• keys to improve outcome:– high index of suspicion– prompt diagnosis and treatment

Predisposing Factors

• HPN – 62-78%• aortic disease

– aortic dilatation/aneurysm– annulo-aortic dysplasia– chromosomal aberration

• Turner’s syndrome• Noonan’s syndrome

– aortic arch hypoplasia– coarctation of aorta– bicuspid AV– heredetary CTD

• Marfan’s syndrome• Ehler’s Danlos syndrome

Predisposing Factors Cont…

• traumatic injury– arterial cannulation during surgery– catheter based diagnostic or therapeutic

intervention– chest trauma– high intensity weight lifting or other strenuous R

training

• cocaine• β blocker withdrawal• women <40, 50% occurs during pregnancy

– HPN in 25-50%

Clinical Presentation

• CP – severe,abrupt, sharp or “tearing” (72.7%) – ant. CP – dissection in asc Ao – post. CP or back pain or abdominal pain -

distal to L subclavian– can radiate anywhere in the thorax or

abdomen – can occur alone or associated with:

syncope M.I.CVA CHF

Clinical Presentation Cont…

• HPN – more common in type B (70% vs 35%)• CHF – (7%)• syncope – (12.7%)• cardiac arrest or sudden death• neurologic – CVA

paralysis• M.I. – (1-2%)

– involvement of coronaries– RCA>L– with thrombolytic – mortality >70%

Clinical Presentation cont…

• Involvement of desc. Aosphlancnic ischemia

renal insufficiency

lower extremity ischemia

spinal cord ischemia

CP or back pain 86% HPN 69%

abdominal pain 43% hypotension/shock 3%

abrupt onset 89% peripheral neuropathy 2%

migratory pain 25% ARF 14%

IRAD Registry

Differential Diagnosis

• myocardial ischemia• M.I. with or w/o ST elevation• pericarditis• pulmonary embolism• AR without dissection• AA with dissection• musculoskeletal pain• mediastinal tumor• pleuritis• PUD/perforating ulcers• acute pericarditis

Diagnosis of Aortic Dissection

• Prediction model for early diagnosis of Ao dissection

– In analysis of 250 patients with CP or back pain, 128 with dissection

– 96% can be identified by combination of 3 clinical predictors:

1. immediate onset of CP with tearing and or ripping character

2. mediastinal and or aortic widening on xray

3. variation in pulse

BP > 20 mmHg between R and L arm

Diagnosis of Aortic Dissection cont…

• when all variables absent 7%

• aortic pain 31%

• mediastinal/Ao widening 39%

• pulse or BP difference or

any combination of the 3 83%

incidence of dissection

Von Kodolitsch et al., Arch Intern Med 2000;160:2977-2982

Diagnostic Procedures

• CXR– widening of mediastinum (60-70% sensitivity)– Ca sign – separation of intimal calcification from

outer aortic soft tissue border by 1 cm

Diagnostic Procedures

• ECG– no specific findings associated with

dissection– 1/3 – LVH – 1/3 – normal – ischemia

Diagnostic Procedures

• TEE– can be done fast, safely and in any

environment• high sensitivity up to 98%• high specificity up to 97%

– specifically informativeAR ostia of coronaries involved

PE CT

Diagnostic Procedures

• TEE limitations:– unable to visualize distal ascending and

descending abdominal aorta– technically difficult in esophageal structures

or varices

Diagnostic Procedures

• CT Scan– identifies 2 distinct lumen with intimal flap– sensitivity with contrast - 83-98%

no contrast - 76-90%– specificity with contrast - 87-100%

no contrast - 70-82%

• advantages: – readily available in most hospitals even on

emergency basis– identifies intraluminal thrombus and PE

Diagnostic Procedures

• limitations:– intimal flap seen in < 75%– site of entry rarely identified– contrast potentially nephrotoxic– cannot assess AR or coronary involvement

Diagnostic Procedures

• Spiral CT– gives accurate 3D view of aorta

• sensitivity – 91- 100%• specificity – 96-100%

– disadvantages• Potentially nephrotoxic, site of entry difficult

Initial interpretation was findings c/w aortic dissection, with thrombosis of the false lumen. Only a small amount of flow is present in the false channel at this point in time, suggesting the dissection may be healing, and stablilizing.

Diagnostic Procedures

• MRI– currently gold standard

• sensitivity – 98%• specificity – 98%

– determines location of intimal tear, secondary tears and branched vessels

– no contrast needed– can detect AR– disadvantages

• limited availability• time consuming • contraindicated in metallic implants

Diagnostic Procedures

• Aortography• sensitivity – 86-88%• specificity – 75%

– procedure of choice in earlier days – now rarely used because it is invasive,

needs contrast and consumes time

What is the Best Modality?

• Depends on:– accesibility– expertise of the institution

Management

• General principle– Aortic dissection of ascending aorta –

surgical emergency– If confined to descending aorta –

medical except when there is hemorrhage into pleural or retroperitoneal space

– In all – prompt control of BP if HPN present

Management

• Medical – uncomplicated distal dissection– stable dissection isolated to aortic arch– stable chronic dissection

Medical Management

• ICU admission• target BP – 100-120 mmHg SBP or lowest

level tolerated to dP/dT (force of ejection of flow from LV) – nitroprusside/nicardepine– β blocker (esmolol, propranolol or labetatol)

• if β blocker contraindicated– verapamil or diltiazem

• if with refractory HPN– evaluate renal artery involvement

“Disease is very old, and nothing about it has changed

It is us who change as we learn to recognize what was formerly imperceptible”

Dr. Jean Martin Charcot

Take Home Message

• Despite recent advancement in diagnosis and treatment, mortality remains high

• We need to continue improvement in prevention, prompt diagnosis and management of this frequently fatal condition

Thank You!