Peripheral Vascular Disease Flashcards
Equation for vessel flow
Q = ((P1-P2)πr^4)/8nL
Equation for vessel resistance
Proportional to nL/r^4
For stenoses of the same length and radius, what factor will cause the biggest pressure drop across the stenosis?
Higher flow
Flow in terms of area and velocity
A1V1 = A2V2
Graph of cardiac cycle and arterial flow
Look at lecture this seems important
High resistance arteries
Muscular arteries (arm, leg) Mesenteric arteries (pre-prandial)
Low resistance arteries
Internal carotids, vertebrals, renals, mesenteric arteries (post-prandial)
Two factors that affect pressure in peripheral veins?
Muscular contraction and respiration.
Three characteristics of normal venous waveforms
Display respiratory phasicity
Augment with calf muscle compression
Display valvular integrity (no retrograde flow on valsalva or increased intra-thoracic pressure).
Paradigm of atherosclerosis
A systemic disease that manifests locally.
What is peripheral artery disease
Atherosclerosis of the aorta, iliac, and lower extremity arteries. Regardless of symptoms, patients with PAD have a 3x increase in CV events.
What are two factors that contribute to PAD development?
Smoking and diabetes.
Intermittent Claudication
Pain or fatigue in calf, thigh, buttock, or lower back that occurs with exertion and is relieved by rest. Location of symptoms corrlates with the level of obstruciton (generally one level below the disease)
Critical limb ischemia
Pain or parathesia in the lower extremity at rest. Exacerbated by leg elevation and relieved with dependency on gravity. Can have ulceration with severe ischemia
Leriche Triad of aortoiliac occlusion
Bilateral buttock/thigh claudication, impotence, and global atrophy
What are the most commonly involved arteries in PAD?
Femoral/popliteal area. Then tibeal/peroneal area, then aortoiliac area.
What area of PAD involvement is hardest to treat? Easiest?
Hardest is tibeal/peroneal. Easiest is aortoiliac.
What area of PAD is affected in DM?
Tibeal/peroneal