Vascular Disease Flashcards
(33 cards)
Atherosclerosis is a generalized INFLAMMATORY disorder of the arterial system associated with ENDOTHELIAL DYSFUNCTION. Name the common pathophysiological causes of atherosclerosis. (4) (i.e. not clinical RF)
- Endothelial damage - caused by hemodynamic shear stress 2. Inflammation - caused by chronic infections 3. Thrombosis - caused by hypercoagulable state 4. Intimal damage - caused by oxidized LDL
What are the layers of the artery?
Outermost externa/adventitia: connective tissue made of collagen Middle media: smooth muscle and elastic tissue Innermost intima: endothelial cells
What is Virchow’s triad?
- Endothelial damage 2. Stasis 3. Hypercoagulability Describes the 3 broad categories that contribute to thrombosis.
How does LDL contribute to the formation of atherosclerosis?
They move through the endothelium, into the intimal layer where they are trapped and become proinflammatory.
Name the risk factors for atherosclerosis? (10)
Modifiable: Cigarette smoking Abdominal obesity HTN Insulin resistance Elevated LDL Reduced HDL Possibly modifiable - depending on etiology: Proinflammatory state Prothrombotic state Non-modifiable: Aging Family hx of premature CAD
What are two of the best predictors for morbidity and mortality after vascular surgery?
Low serum albumin and high ASA classification. Others included: esophageal varicies, DNR status, ventilatory dependent, emergency surgery, elevated CR
What clinical syndromes are associated with aortic atherosclerosis? (2 + 3)
AAA Aortic dissection Peripheral atheromembolism Penetrating aortic ulcer Intramural hematoma
Define peripheral arterial disease (PAD).
Atherosclerosis affecting the limbs
Ankle-brachial index is the best screen for PAD. Define ratios for normal, vessel hardening, PAD, and critical.
Greater than 1.2 = vessel hardening 1-1.2 = normal Less than 0.9 = abnormal Less than 0.4 = critical, limb threatening ischemia
How is the ABI measured?
Patient must be supine. SBP for brachial artery SBP for posterior tibial and dorsal pedis - high SBP taken SBP ankle artery : SBP brachial artery
What is the standard method for diagnosing PAD?
Catheter based angiography. Note: MR- and CT- angiography are becoming more common.
Risk of AAA rupture is very low below which diameter?
Less than or equal to 4cm
Between 4-5cm a AAA should be monitored by US every how many months?
6mos
T/F: Baseline Hgb is independently associated with AAA size and reduced longterm survival following intervention.
True. This allows for additional risk stratification.
Continuation of which of the following chronic medical therapies may reduce perioperative m&m following vascular sx: Beta blockers ACEi Statins ASA Hypoglycemics and insulin
ALL: Beta blockers ACEi Statins ASA Hypoglycemics and insulin
Name 4 benefits to starting statins preoperatively and continuing them post op, WRT vascular sx.
- Mortality - patients who received statins were less likely to die 2. Decreased cardiac peri-op morbidity - patients in whom statins were stopped in the 4 day peri-op period were at increased cardiac risk. 3. Improved graft patency 4. Improved limb salvage, decreased amputation rate
Chronic ASA and other anti-inflammatory drugs may stop the progression of atherosclerosis and CV events. What are the general recommendations regarding ASA and clopidogrel use in peri-op period (assuming no stent)?
Clopidogrel - does not increase risk of mjr bleeding if restarted 48H after PV sx ASA - take until day of sx for carotid and PV sx. Individualized for larger (ex aortic) sx.
Absence of SEVERE CAD can be predicted (96% PPV) in patients without these 4 clinical RF.
Diabetes CHF Prior angina Previous MI Take home point: Clinical RF predict severity of CAD
Describe how remote vs recent PCI is associated with cardiac morbidity following non-cardiac sx.
Remote - May be protective Less than 6 weeks - Increased risk Note that PCI done to reduce cardiac risk does NOT reduce periop MI
What are the current anti-platelet guidelines following stent placement?
ASA 325mg/d and clopidogrel 75mg/d BMS: 1 month DES: 12 months Then ASA indefinitely
What are the current guidelines for ASA and clopidogrel if the patient has a stent?
Continue ASA in ALL patients with stents. Discontinue clopidogrel for as short a period as possible. Specifically, holding for 8 days may not be necessary.
What is an early periop MI?
Acute non-surgical MI. Most likely due to coronary occlusion by plaque rupture or thrombosis.
What is a late periop MI?
Most likely demand MI in setting of fixed coronary stenosis. Associated findings: increased HR, absence of CP, prolonged period of STD prior to MI.
Post op, what could increase O2 demand? Decrease O2 supply?
increase O2 demand Increased HR or BP secondary to pain Decrease O2 supply Anemia Hypotension.
