Cardiology · USMLE Step 1 and Step 2

Atherosclerosis song

Atherosclerosis - Pathogenesis & Plaque, as a song. Hear the short teaser here. The full song is on YouTube and Spotify.

Atherosclerosis

Full song on YouTube ↗Spotify ↗

Key points in this song10

Atherosclerosis begins with endothelial injury caused by risk factors such as hypertension, hyperlipidemia, diabetes, and smoking, leading to endothelial dysfunction and increased permeability.
LDL particles accumulate in the intima and undergo oxidative modification; oxidized LDL is the key driver of the inflammatory cascade in plaque formation.
Endothelial dysfunction upregulates adhesion molecules (VCAM-1, ICAM-1), recruiting circulating monocytes that transmigrate into the intima and differentiate into macrophages.
Macrophages engulf oxidized LDL via scavenger receptors (not LDL receptors), transforming into lipid-laden foam cells — the hallmark of the fatty streak, the earliest visible lesion.
Fatty streaks are reversible lesions found even in children and adolescents; they appear as yellow intimal discolorations and do not obstruct flow.
Smooth muscle cells migrate from the media to the intima under the influence of PDGF and proliferate, secreting extracellular matrix to form the fibrous cap of an advanced plaque.
A stable plaque has a thick fibrous cap and small lipid core; a vulnerable plaque has a thin fibrous cap, large lipid core, and abundant inflammatory cells — prone to rupture.
Plaque rupture exposes subendothelial collagen and tissue factor, triggering platelet aggregation and the coagulation cascade, leading to acute thrombotic occlusion and myocardial infarction.
The tunica intima is the primary site of atherosclerotic plaque development; the tunica media undergoes atrophy due to ischemia from the expanding plaque.
High HDL is protective because it mediates reverse cholesterol transport, removing cholesterol from peripheral tissues and foam cells back to the liver for excretion.