Peripheral Vascular Disease Flashcards
Arterial stenosis is usually a result of what?
Atherosclerosis
Venous stenosis is usually a result of what?
Thrombosis
list 4 PAD risk factors
Diabetes (4-fold increased risk)
Smoking (2-3 X)
Lipids (2 X)
Hypertension (2X)
Are PAD patients at increased risk for CV death?
YES. 6-fold increased risk of CV death
What are the manifestations of PAD?
-Intermittent Claudication
describe blood flow in intermittent claudication
Blood flow normal at rest (no Sx), limited with exercise (Cramp, calf fatigue )
Describe the blood flow resulting in Ischemic rest pain/ischemic ulcers
Blood flow limited at rest and exercise (constant Sx)
- Pain in the distal foot or heel, worsened by leg elevation and improved by dependency
- Distal, painful ulcers on toes or heel
List some physical findings in patients with PAD
Decreased or absent pulses Bruits (abdominal, femoral) Muscle atrophy Pallor of feet with elevation (Severe PAD) Dependent rubor (Severe PAD)
What determines the severity of atrial stenosis?
Radius & length of the stenosis
What is the ABI index?
Ankle-Brachial Index, looks at the extent of peripheral stenosis by comparing arm BP to ankle BP.
Ankle SBP/Arm SBP = ABI
Ratio < 0.90 = PAD
What are the treatment GOALS for claudication?
- Prevent CV events (MI, stroke, vascular death)
- Improve limb symptoms, exercise performance and QOL
- Heal ulcers and prevent limb loss
What treatment options do you have for claudication?
Surgery or angioplasty improves hemodynamics
Exercise training improves muscle metabolism
Drugs (cilostazol) have multiple mechanisms
What is an arterial aneurysm?
Pathological expansion of all three arterial layers
Normal diameter of the aorta
3 cm at its root;
2.5 cm mid descending thoracic aorta;
2 cm at the infra-renal aorta
When would you classify an expansion in the abdominal aorta as a AAA?
- denoted by diameter of > 3.0 cm
- Or 50% increase in size relative to proximal normal segment
List the 4 mechanisms leading to aortic aneurysm formation
-Weakened Aortic Wall (low collagen/elastin)
What is the 13th leading cause of death in the US?
Ruptured aneurysms, Annual incidence estimated 40 to 50 per 100,000 men and 7 to 12 per 100,000 women
AAA risk factors
Age
Gender
Smoking
Family history
How do AAA patients present?
- 70% of patients are asymptomatic, then present with sudden death
- 30% present with abdominal discomfort or severe pain radiating to the back, then die
What diagnostic tests can be used to Dx AAA?
Plain X-ray Ultrasound Computerized tomography Magnetic resonance imaging Arteriography (May miss it because angiography views the lumen not the arterial wall)
Prevalence of aortic dissections
~ 30 cases / million / yr
3-5 % sudden deaths
What are the 2 mechanisms of aortic dissection?
Primary Intimal Rent/Tear
Risk factors leading to aortic dissection
Hypertension (drugs e.g. cocaine) Inherited disorders of connective tissue Marfan syndrome Ehlers-Danlos syndrome Bicuspid aortic valve and more...
Presentation of pts w/ aortic dissection
-C/o severe, tearing pain
-Disruption of major arterial circulation leads to:
Stroke (carotid)
Syncope (vertebral)
Myocardial infarction (coronaries)
Intestinal ischemia (mesenteric vessels)
Renal failure (renal arteries)
medical Tx of aortic dissections
- Control of Pressure/Time: Beta Blockade
- Control of Blood Pressure: Nitroprusside, ACE inhibitors, Calcium Channel Blockers
- Control of Pain: Narcotic analgesia
T or F: Nearly 2/3 of VTE are asymptomatic or undiagnosed
True
Prevalence of VTE in patients w/ hx of MI, stroke & hip surgery
24% of MI patients develop VTE
60% of paralytic stroke patients develop VTE
75% of hip surgery patients develop VTE
Stages of chronic VTE
Stage 1: swelling
Stage 2: Visible collateral’s
Stage 3: stasis dermatitis
Stage 4: ulcers
Components of Virchow’s triad
Injury
hypercoagulability
Abnormal flow (stasis)
Mechanisms of thrombophilia
Imbalance in coagulation that causes the following:
- increases thrombin production
- enhances platelet activation/aggregation
- mediates endothelial activation/damage
- and/or mediates fibrinolytic inhibition
Thrombophilia risk factors
- Severe inherited thrombophilia (homozygous protein C deficiency) is rare
- Mild inherited thrombophilia (heterozygous Factor V Leiden) is common
- Acquired thrombophilia is especially common in infection, inflammatory and certain drugs
Parenteral Xa inhibitors
Heparin, LMWH
Parenteral direct thrombin inhibitors
Argatroban, Dabigatran (can be oral as well)
Direct oral inhibitors of Xa
Apixaban
Oral anticoag targeting II, VII, IX, X
Warfarin
