Aortic Dissection/Venous Thromboembolism Flashcards
Cases per year of aortic dissection? What allows this to happen?
• Approximately 5000 cases per year • Intimal tear allows hematoma to form between intima and adventitia (Cystic medial necrosis) • 10-15% vaso vasorum rupture causes intramural hematoma
Explain the Stanford Classification?
• Stanford classification • Type A involves ascending aorta and originates at the aortic valve level (2/3 of cases) • Type B involves descending aorta and originates at ligamentum arteriosum
DeBakey Classification?
• DeBakey classification • Type I Ascending and descending • Type II Ascending only • Type III Descending only
Causes of Aortic Dissection?
• Marfan’s syndrome • Ehlers-Danlos syndrome • Hypertension • Trauma (blunt or iatrogenic) • Pregnancy (half of women cases under age 40) • Bicuspid aortic valve independent of stenosis gradient • Age 50-70 • Male to female 2:1 • 90% of acute cases of ascending dissection have no recognized substrate
Physical symptoms of Aortic dissection?
• Sudden onset of intrascapular pain that radiates to extremities more likely descending aorta • Chest pain through to back more likely ascending aorta • Pleuritic chest pain may represent pericardial effusion • Abdominal pain if involves mesenterics • Neurological changes involving cerebral distribution
Imaging for Aortic stenosis?
• CXR (sensitivity 67%) • EKG non specific most common • CT Scan gold standard now with new scanners • TEE excellent sensitivity and specificity • MRI lack of availability and length of scan • History and physical exam
Physical exam findings of Aortic dissection?
• Water Hammer Pulse-created by widened pulse pressure—- boards. • Aortic Insufficiency diastolic murmur • Differential blood pressure between arms • Gallop rhythm S3 or S4 due to rapid ventricular filling and possible myocardial infarction- this is super advanced probably won’t come up ever.
Aortic Dissection mortality rates?
Mortality 1-2% per hour in first 24 hours
50% first week
75% first month
90% first year
Management of Aortic Dissection?
- Blood pressure control to a mean arterial pressure of 60-75 desirable
- Sodium nitroprusside with a beta blocker (esmolol, labetalol) first line therapy
- IV cardizem/diltiazem second line with combined decreased blood pressure and inotropic effect
- Refractory hypertension consider renal artery involvement
- Surgical intervention required for ascending disease
- Medical therapy for descending dissection
Ascending vs. descending super important.
Risk factors for Aortic Dissection?
Aortic Dissection
• Advanced age
- Aneurysm leak
- Concominant CAD
- Renal Failure
- Pericardial effusion/tamponade
- Shock
Most Venous thromboembolism are? Incidence? Mortality?
- Venous thromboembolism (VTE) • Most common are deep vein thrombosis (DVT) and pulmonary embolism (PE)
- Incidence of VTE is about 1/1,000 in the US
- Death occurs within one month of an episode in about 6% of those with DVT and 10% of those with PE • Mortality rate for pulmonary embolism approaches about 30% • There is also significant morbidity • Post-thrombotic disorder • Pulmonary hypertension
What is Virchow’s Triad? This is a must know.
- Hypercoagubility • Surgery • Cancer • Inherited disorders
- Stasis (IE immobility or anatomical factors reducing blood flow) • May-Thurner
- Endothelial injury
Risk factors for Venous thromboembolism?
- More than half of patients presenting with VTE have three or more of the following six risk factors present at the time of VTE
- >48 hours of immobility in the preceding month;
- hospital admission
- Surgery
- malignancy,
- infection in the past three months
- current hospitalization
Hemostasis process?
- Formation of the platelet plug
- Adhesion, aggregation, secretion, propagation (platelet factors)
- Initiation of clotting cascade
- exposure to collagen/TF and interaction with Factor VII
- TF and VIIa activates Factor X
- Factor Xa and Va convert prothrombin to thrombin
- Thrombin activates Factors V, VIII, IX, Fibrinogen Fibrin Thrombosis
DVT should be suspected in patients with what features?
- DVT should be suspected in patients who present with leg swelling, pain, warmth, and erythema • Swelling or edema – 97 (sensitivity) and 33 percent (specificity) • Pain – 86 and 19 percent • Warmth – 72 and 48 percent
- Assess for risk factors of VTE (discussed previously)
- Personal and family history of VTE
Pulmonary embolism presenting features?
- Pulmonary embolism (PE) has a wide variety of presenting features, ranging from no symptoms to shock or sudden death
- Most common presenting symptom is dyspnea (73% of patients) and this is usually rapid in onset
- Other common features include chest pain (classically pleuritic in nature), cough, and symptoms of deep venous thrombosis
- Syncope can also be the presenting symptom, though this is not common (210% of patients with PE)
Physical findings of DVT? PE?
- Leg swelling, warmth, erythema • Degree of swelling dependent on size and location of DVT • Proximal DVT could have entire leg involvement • Bilateral swelling is uncommon
- For pulmonary embolism • Tachycardia • Tachypnea • Hypoxia • JVD • Lung sounds generally normal • Loud P2 component of heart sounds • Fever (~3% of patients)
EKG findings of PE?
- Most common finding = sinus tachycardia_ BOARDS!!!!!!!!!!!
- Other findings are generally non-specific and insensitive. Finding of “S1Q3T3” is fairly specific for right ventricular strain and is present in a minority of PE.
What does this chest X-ray show?
Hampton’s Hump:
Shallow, hump-shaped opacity in the periphery of the lung, with its base against the pleural surface and hump towards the hilum
What does this Chest X-ray show?
Westermark’s Sign:
Demonstration of a sharp cut-off of pulmonary vessels with distal hypoperfusion in a segmental distribution within the lung
What are the deep veins in the legs?
Superficial femoral vein is also a deep vein (trick question on boards). This is also called “femoral vein”
