Flashcards in Clinical Atherosclerosis Deck (39):
If you have SYMPTOMATIC peripheral arterial disease (PAD), is there a good chance you have a flow limiting coronary artery disease, or more?
If you have DIAGNOSED peripheral arterial disease (PAD), do you have an 8x increase in cardiac mortality?
Where is most PAD?
Where is the most common atherosclerotic narrowing in a NON-DIABETIC pt?
mid-thigh (superficial femoral artery)
Where is the most common atherosclerotic narrowing in a DIABETIC pt?
the popliteal trifurcation (anterior tibial, posterior tibial, and peroneal; fibular)
What are the symptoms of peripheral arterial disease (PAD)?
intermittent claudication= cramping pain in the leg (calf muscle) is induced by exercise, typically caused by obstruction of the arteries. This occurs due to the cells undergoing anaerobic respiration, generating lactic acid. Therefore, the more you walk, the more it hurts.
As the disease progresses, shorter distances/less exercise will induce the pain.
Do many pts tolerate intermittent claudication (leg cramping)?
YES until it makes their lives stink!
In your work up what should you always ask if the patient complains of leg cramping (intermittent claudication?
When you walk do your legs hurt? How far do you go? What does the pain feel like? Does it go anywhere from there?
Aka you work it up just like you would for angina pectoris to see if it is from the heart.
Will foot pain also accompany leg pain in DIABETICS with PAD?
Is atherosclerosis a metastatic process?
How do we quantitate PAD?
with an ankle-brachial index (ABI). When it is 0.90 or less you have PAD. It should always be greater than 1 in a healthy patient.
What is the most common access site for an angiogram?
common femoral (off the external iliac)
What ultrasound exam is performed first to locate the disease exactly?
Arterial duplex scan
What important skeletal muscles does the internal iliac supply, and why is this important?
ipsilateral gluteus maximus and upper thigh. So if this is diseased, you will get pain in the butt and upper thigh.
Why is PAD of the internal iliac commonly misdiagnosed?
L1-2 radiculopathy (disease of nerve root) goes right through this band and is written off after x-ray as arthritis.
What is the end artery of the internal iliac in a male, and why is this important?
pudendal artery (supplies genitalia). So if this is diseased, you will lose loss of erectile function (ED).
What are the 2 reasons for erectile dysfunction?
1. vascular (75%)= if proximal you can significantly improve with a stent (angioplasty). Small vascular (mainly diabetics) respond well to PDE5 inhibitor medications (Levitra, Cialis, Viagra) because most of these receptors are found in the penis and lungs.
2. supratentorial (25%)= stress, depressed...
What happens when you take a PDE5 inhibitor?
it explodes nitric oxide (NO) in the penis and lungs, causing vasodilation (inflow is improved) and relaxes smooth muscle, improving erectile function.
Do female pts take PDE5 inhibitos?
YES for treatment of pulmonary hypertension, because there are many PDE5 receptors in the pulmonary arteries.
What should be a part of every differential in your review of symptoms for GU for male pts?
Do urologists have a quantitative measurement for someone who comes in with internal iliac disease?
YES. penile-brachial index (PBI); cuff that goes on the penis. If it is 0.6 or less, you have internal iliac disease and a vascular etiology for your ED.
How does the ankle-brachial index (ABI) work?
measure the systolic pressure of the brachial artery, and the systolic pressure of the 3 ankle arteries with doppler.
Why do very small changes in vessel radii have larger pressures?
due to Bernoulli's perfusion principle: systolic pressure= r^4 . So pressures in the ankle should always be higher than in the arm (w/o PAD). This is why it should always be greater than 1 for healthy individuals.
What is the number 1 risk factor for PAD?
Will you have micro-ischemia before pain sensation?
Does ischemia cause vasodilation?
YES and this is why the pressures will drop in the ankle compared to the brachial artery in those with PAD. It is a compensatory mechanism.
What is the other compensatory mechanism for ischemia besides vasodilation?
What will smoking just 1 cigarette do to those with PAD?
spasm off collateral circulation that you've built up for compensation, and vasodilate less for 6-8 hours. Plus you increase platelet activity, clotting off these tiny arteries :(
What kind of studies do we do now first if you have symptoms of PAD?
MPI (myocardial perfusion study). You get this before balloon/stent or surgery of leg. In most cases, active coronary disease is found, that has not yet expressed itself (many are diabetics). These patients don't get chest pain, but instead get dyspnea with exertion (aka their anginal equivalent).
Why do diabetic patients develop silent ischemia?
because they have neuropathy of their pericardium (where most pain receptors of the heart are found), and don't feel the pain of ischemia that non-diabetics would feel.
What is the formula for ABI?
ANKLE systolic pressure/ BRACHIAL systolic pressure
What is the most common atherosclerotic vessel of the upper extremity?
left subclavian artery off of the aorta. This means that as this gets tighter and tighter, your left brachial pressure will get lower and lower.
What is vertebrobasilar steal syndrome?
the resistance in the left arm drops below the posterior circulatory resistance of the brain, so instead of the blood flowing up to the brain, it reverses and comes back toward the arm. This is a cause of syncope in the elderly that docs rarely look for, but you should!
What is the the other cause of vascular syncope other than vertebrobasilar steal syndrome?
carotid sinus hypersensitivity
***Dr. Arnold's pearl for us: What are the 2 things you should always check for first when a patient comes in with syncope?
1. vertebrobasilar steal syndrome
2. carotid sinus hypersensitivy
***What is an example of how to do an ABI?
RA= 100 mm H, LA= 90 mm Hg
RL= dorsalis pedis=110, posterior tibial= 100, peroneal= 90
LL= DP= 60, PT= 70, P= 50
*Use highest of arm pressures for both denominators.
*Use highest of each ankle pressure for the numerator.
Right ABI= 110/100 = 1.1
Left ABI= 70/100 = 0.7
If the patient complains of his/her left leg hurting, this confirms his symptoms and thus PAD.
What 3 sounds should you listen for using the doppler in the ankle arteries?
triphasic, biphasic, or monophasic sounds :(
**What ABI values must we know?