deck_5326143 Flashcards
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 stress2. Inflammation - caused by chronic infections3. Thrombosis - caused by hypercoagulable state 4. Intimal damage - caused by oxidized LDL
What are the layers of the artery?
Outermostexterna/adventitia: connective tissue made of collagenMiddlemedia: smooth muscle and elastic tissueInnermostintima: endothelial cells
What is Virchow’s triad?
- Endothelial damage2. Stasis3. HypercoagulabilityDescribes 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 smokingAbdominal obesityHTNInsulin resistanceElevated LDLReduced HDLPossibly modifiable - depending on etiology:Proinflammatory stateProthrombotic stateNon-modifiable:AgingFamily 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)
AAAAortic dissectionPeripheral atheromembolismPenetrating aortic ulcerIntramural 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 hardening1-1.2 = normalLess than 0.9 = abnormalLess than 0.4 = critical, limb threatening ischemia
How is the ABI measured?
Patient must be supine.SBP for brachial arterySBP for posterior tibial and dorsal pedis - high SBP takenSBP 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 blockersACEiStatinsASAHypoglycemics and insulin
ALL:Beta blockersACEiStatinsASAHypoglycemics 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 die2. 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 patency4. 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 sxASA - 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.
DiabetesCHFPrior anginaPrevious MITake 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 protectiveLess than 6 weeks - Increased riskNote 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/dBMS: 1 monthDES: 12 monthsThen 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 demandIncreased HR or BP secondary to painDecrease O2 supplyAnemiaHypotension.
Draw the algorithm for cardiac evaluation for non-cardiac sx
What are the “Major” perioperative cardiovascular RF as defined by the AHA/ACC? (6)
Acute MI (less than 7 d)Recent MI (7-30 d)Unstable anginaDecompensated CHFSevere valvular dxSignificant dysrhythmias
What are the “Internediate” perioperative cardiovascular RF as defined by the AHA/ACC? (5)
Hx of ischemic HD (ex. angina, prior MI)CHF - hx of, or compensatedDMRenal insufficiencyCVD
What are the “Minor” perioperative cardiovascular RF as defined by the AHA/ACC? (4)
Age > 70Adn ECGRhythm other than sinusUnconrtolled systemic HTN
Should patients with known CAD undergo coronary revascularization prior to vacular sx?
There was no benefit to revasculartization (vs. medical therpay) in patients in whom revascularization was not otherwise indicated for ACS (ex. left main dx,EF less than 20%)Medical therapy = beta blockers, ASA, statins
If coronary revascularization is indiciated prior to vacular sx, which method (sx vs PCI) is associated with better outcomes?
Surgical revascularization, i.e. CABG
Assuming stents are not also inserted, what is the safe time interval between coronary revasculartization and vacular sx?
PCI = 2 weeksSurgical revascularization = 4-6 weeks
What is the treatment of HIT?
Stop heparinFull anticoagulation with direct thrombin inhibitor3 weeks of warfarin rx: note warfin therapy alone can diminish protein c and s and promote thrombosis
