Arterial Disease

Deox blood to r heart → oxygenated → ox blood to left heart

Structure:

  • Muscular a - more smooth m in tunica media

  • Elastic a - more elastic tissue in tunica media

    • maintains constant p gradient

  • Arterioles - smooth m → role in vasc resistance

    • influenced shape by autonomic system

  • Capillaries - single endothelial layer

    • transport O2 + nutrients via diffusion

Arterial walls

  1. Adventitia : structural

  2. Tunica media : elastic + m tissue

  3. Tunica intima : endothelium for frictionless pathway

Aorta + big a - high p reservoirs

Small a + arterioles - resistance vessels

Capillaries - exchange vessels

Veins + venules - storing vessels

Hemodynamics:

  • Metarterioles have pre-cap sphincters (metabolic control)

  • Peripheral vasc resistance - resistance in circ system to create BP + flow blood (constriction → increase SVR)

  • Bernoulli’s principle - fluid flows steadily, total energy constant

  • Poiseuille’s law - viscous losses in idealized situation

  • Only big drop BP in body is from a to arterioles

  • Modifying radius vessel affects resistance

  • High shear stress → endothelial damage

  • Low shear stress → atherosclerosis

Thrombosis:

Due to endothelial lesion + exposure collagen

In high-flow areas (Zahn’s lines appear)

Embolism: obstruction lumen w/ circ. matter, fragmented thrombus → thromboembolism

Atherosclerosis: chronic inflammatory disease of a

  • accumulation LDL + inflammation @ regions of non-laminar flow

  • cause ASCVD

ASCVD:

  • risk factors - hypercholesterolemia, htn, dm, cigs, old men, family history

  • sup femoral a most affected

Carotid + coronary atherosclerosis

PAD + coronary atherosclerosis

Atheroma: combo changes in intima of a., of entire arterial wall

Aneurysm: dilatation of a.

  • aneurysmosis - multiple aneurysms affecting a vessels

  • pseudoaneurysm - pulsatile hematoma from traumatic disruption of a. wall

PAD: stenosis/occlusion aorta or branches → claudication + trophic lesions of lower leg

  • intermittent claudication - inadequate limb flow if pain @ rest

  • critical limb ischemia - limb pain at rest, ‘end stage’

  • systolic murmurs on auscultation

  • Allen-Ratschow test - lig leg 1m, color returns >20s = ischemia

Treatment - lifestyle, drugs, immunosuppressive for vasculitis, pain therapy

  • sympathectomy, revasc surgery, endarterectomy, bypass, endovasc treatment

Classification chronic ischemia

  1. pain @ big effort

  2. mild claudication (>50mmHg after exercise test) or severe claudication (can’t finish exercise test, <50mmHg)

  3. rest pain, no podal pulses

  4. trophic lesions/gangrene