Flashcards in Heart Lecture (#2) - Skilling Deck (46):
Where is most of the blood? Venous or Arterial side?
Venous side - veins are more distinctable
What are the two different types of arteries?
Muscular and non-muscular
What are the different layers of arteries?
Adventitial - Holds everything together
Initmal Layer - in contact with the blood
Medial layer - in between
What is unique about the tunica intima?
It is composed of endothelial cells - one of the few surfaces that can maintain blood in a liquid state. Blood should not clot there; keep moving
Also possesses many mechanisms that can go awry and lead to atherosclerosis
Arteries have elastic layers and concentric layers of smooth muscle cells
What is unique about the tunica adventitia?
Outermost layer of the artery - possible roles in artierial homeostasis and pathology
Contains collagen fibrils that contribute to the strength of the artery
Other cells found here: mast cells & fibroblasts
**Vasa vasorum and nerve fibers are localized here**
What is unique about atherosclerosis?
3 different theories prove to play a role in CVD
Atherosclerosis diffusely affects certain regions preferentially in large and medium arteries. At the same time, it produces focal stenosis in certain areas of affected vessels much more than in other areas
Few diseases have an longer "incubation" period than atherosclerosis:
-Begins shortly after birth
-Hyperlipidemia at 200
-Infants have total cholesterol levels at 100
Do you want more anticoagulants or procoagulants?
You want a 50/50 balance
What kind of cells are only seen in atherosclerosis?
smooth muscle cells proliferate and migrate - large arteries become smaller - attacked by LDL
-Intima is injured - blood clots - disrupts blood flow
--or can break off and become an emboli
What is the one biggest risk factor by far for developing PAD
Cigarette smoking, others aren't even close
DM is distant 2nd (95% CI)
What's the deal with Arteriogenic ED?
Age of Onset for ED and CAD is often similar!
ED can be a warning sign of CAD in asymptomatic men
ASCVD and ED share the same risk factors - smoking, diabetes, hypercholesterolemia, hypertension
Factors decreasing blood supply to the limb?
Flow limiting lesion
Impaired vasodilation (decreased NO; reduced responsiveness to vasodilators)
Abnormal rheology (reduced RBC deformability, increased leukocyte adhesiveness, platelet aggregation, microthombosis, increased fibrinogen)
What affects Hemodynamics (flow through an artery)?
Directly proportional to perfusion pressure
Inversely proportional to vascular resistance
E.g. high vascular resistance (small artery) slows down blood flow
Which organs have highest percentage of cardiac output?
1. Liver - 27%
2. Kidney - 22%
3. Brain - 14%
What does relaxation of arterioles and precapilary sphincters do?
Increase tissue blood flow
In response to decreased tissue O2
What connects arteries and veins?
Arteriovenous anastomosis in the subcutaneous tissue
Capillaries get nothing if there is a disruption above
What is the Cardinal Symptom of PAD!
Calf pain (intermittent claudication)
It appears with exercise and resolves with rest
-Reliable, reproducible, and consistent
Location of sxs relates to site of most PROXIMAL arterial stenosis
What is a collateral vessel?
Small vessel that forms to bypass blockage
Most common DDX of Exertional Leg Pain??
Lumbrosacral radiculopathy (neurogenic claudication)
-Leg pain caused by neuropathy
If you have pain in the calf, what artery or arteries are likely involved?
Femorals or popliteals
If you have pain in the buttock, hip, or thigh, what artery or arteries are likely involved?
Aortic or iliac arteries
If you have pain in the ankle or foot, what artery or arteries are likely involved?
Tibial or peroneals
If you have pain in the shoulders, biceps or forearm, what artery or arteries are likely involved?
UE subclavian, axillary, or brachials
Which muscle consumes the most O2 during walking?
The gastroc. This is why calf claudication is the the most frequent symptom
If pain occurs at rest, is it intermittent claudication?
Pain at rest, like nocturnal night cramps, are not due to PAD
Pain with I.C. should subside after rest
Exercise is effective, but must convince the patient
What can you suspect if you have leg pain at rest
(likely a critical wound ischemia - leads to amputation)
Typically in toes or foot, worsens with elevation
Pain improves with leg dependency (pts sleep with affected leg hanging from bed)
Extreme skin sensitivity
Gout - cannot tolerate shearing forces at the foot
What are the 5 P's of critical limb ischemia?
(Some also include Poikilotherm - widely varying temp)
Characteristics of Arterial Skin Ulcers?
Most distal areas
Round, regular boarders
Poor capillary refill
Characteristics of Venous Skin Ulcer
Lower third of leg; malleolar area
What is the Fontaine Classification? (refer to PPT for full answer; won't display whole answer for some reason)
I - none
II - Intermittent Claudication
IIa - Pain-free, IC walking, > 200m
IIb - pain-free, IC walking
Clinical categories of chronic limb ischemia?
I(0) - Asymptomatic
I(1) - Mild claudication
I(2) - Moderate claudication
I(3) - Severe Claudication
II(4) - Ischemic Leg Pain
II(5) - Minor tissue loss; nonhealing ulcer, focal gangrene, diffuse pedal ulcer
III(6) - Major tissue loss extending above the transmetatarsal level, functional foot no longer salvageable
First symptom with impaired LE cardio?
Also check rubor - from red to white
How to take BP according to Skilling, PA-C (KNOW FOR EXTRA CREDIT ON QUIZ!) - see PPT for full answer; won't properly display (slide 54)
Upper arm at heart level - hold their arm in your armpits
Cuff L and W should be 80 and 40% of arm circumference, respectively
How should you measure Leg BP?
By using a thigh cuff and Doppler probe at the posterior tibial artery
Tell me about the ABI
1.0 - 1.2 is normal (per Adrienne, >1.2 is indicitive of bad things)
Per Skilling, > 0.9 is abnormal. Per everyone else, > 0.8 is abnormal
0.5 - 0.8 = cause claudication
How do you treat PAD?
Aggressively treat the underlying problem
Control BP and hyperlipidemia
Progressive exercise training - better than placebo
Local wound care
Avoid saying "it may take awhile"?
Take care of your feet
Do you want to take Aspirin or Clopidogrel (Plavix) for PAD
Plavix/Clopidogrel for PAD
Aspirin to prevent MI (Statins help too)
Can be taken in combination`
What medication do you take for Intermittent Claudication?
What's more effective (per Skilling): Bypass or Graft?
Grafts. Veins have valves - will eventually be as strong as an artery
ABI is normal. Venous or Arterial Skin Ulcer?
Lower 1/3 of leg. Venous or Arterial Skin Ulcer?
Venous (Arterial are most distal areas)
Ulcer has regular borders. Venous or Arterial Skin Ulcer?
Arterial (Venous has irregular borders)
Ulcer has dermatitis, hemosiderin, "bottle leg" and eczema. Venous or Arterial Skin Ulcer?
Venous (Arterial has no bleeding, dry base, "shiny", and hair loss)
Edema. Venous or Arterial Skin Ulcer?
What is PAD?
i. Defined as partial or complete obstruction of one or more peripheral arteries due to atherosclerosis resulting in reduced blood flow to the limbs.
ii. aka atherosclerosis of the extremities
What is PVD
i. Is considered a big umbrella term.
ii. PVD can either be Peripheral Arterial Disease or Chronic Venous Insufficiency (aka venous stasis disease)