RIU 436 Lecture Notes - Lecture 19: Medical Ultrasound, Peripheral Artery Disease, Vascular Resistance
7 Jul 2020
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Document Summary
Physiologic arterial testing : focusing on lower extremities. The overall purpose of the vascular laboratory in patients with known or suspected lower extremity. To confirm the presence of arterial insufficiency. Provide quantitative and reproducible physiologic data concerning its severity. Doppler pulses - check for changes in artery- specific doppler waveform morphology per segment of limb changes. Plethysmographic waveforms- check for changes in overall waveform morphology, per segment of limb. Looking for changes in flow from segment to. Not trying to pinpoint exact location of segment disease. Normal doppler waveforms are bidirectional and bi-to triphasic. Interpretations of doppler waveforms is limited to their shape. Paod reduces flow energy distal to the lesion. Volume flow is maintained in this way until paod reaches critical stage. As a vessel dilates it looses pulsatility. Arteriolar bed can no longer dilate to increase blood flow. Increase in velocity= decrease in pressure in that area. For ankle brachial indexed (abis), cuffs are.
