STEPTRACKERCARDIOVASCULAR | PATHOLOGY + PHYSIOLOGY | HIGH-YIELD REVIEW

Hypertension & Arteriolosclerosis

Long-standing pressure remodels small arteries; the type of arteriolar change tells you whether the hypertension was chronic or malignant.

FOCUS ON
Know the secondary causes by their clues (bruit, low K⁺, episodic spells, arm–leg gradient). Hyaline arteriolosclerosis (pink, glassy) comes from benign HTN and diabetes. Hyperplastic ("onion-skin") comes from malignant HTN. Hypertensive emergency means high BP with acute organ damage.
TOPIC
DETAIL
MECHANISM
CLUE
Primary (essential) HTN
~95%
No single cause; genetics, salt, obesity, age; more common and severe in Black patients.
↑ peripheral resistance, renal sodium handling
Major risk factor for CAD, stroke, HF, CKD, dissection
Renal artery stenosis
secondary
Atherosclerosis (older men) or fibromuscular dysplasia (young women, "string of beads").
↓ renal perfusion → renin ↑ → angiotensin II, aldosterone
Abdominal bruit; creatinine jumps on ACE inhibitor if bilateral
Other secondary causes
Primary aldosteronism, pheochromocytoma, Cushing, coarctation, sleep apnea, CKD, OCPs, hyperthyroidism.
Hormone excess or obstruction
HTN + ↓ K⁺ + low renin → aldosteronism · arm BP > leg BP → coarctation
Hyaline arteriolosclerosis
Pink, glassy, homogeneous thickening of arteriolar walls.
Plasma proteins leak into the wall (benign HTN); non-enzymatic glycosylation (diabetes)
Kidney: shrunken, finely granular cortex (nephrosclerosis)
Hyperplastic arteriolosclerosis
Concentric "onion-skin" layers of smooth muscle and basement membrane ± fibrinoid necrosis.
Abrupt, severe pressure rise
Malignant HTN, scleroderma renal crisis; "flea-bitten" kidney
Hypertensive emergency
BP typically > 180/120 with acute end-organ damage (encephalopathy, papilledema, AKI, MI, pulmonary edema, dissection).
Autoregulation fails → vessel injury
IV labetalol, nicardipine, nitroprusside; lower MAP ≤ 25% in first hour
Target organs
Heart: concentric LVH, diastolic HF, CAD, AF · brain: lacunes, Charcot-Bouchard microaneurysms · kidney: CKD · eye: retinopathy · aorta: dissection.
Chronic pressure + arteriolar narrowing
Retina: AV nicking, flame hemorrhages, cotton-wool spots, papilledema
Mönckeberg medial calcific sclerosis
Calcification of the media of muscular arteries (radial, ulnar, femoral) in older adults.
Lumen not narrowed — not obstructive
"Pipestem" arteries on x-ray; non-compressible vessels (falsely high ABI)

Mechanism — pressure remodels arterioles

Chronic mild ↑ BPor diabetes
→
Protein leak into wall
→
HyalineNarrow, stiff arterioles
Sudden severe ↑ BP
→
Smooth muscle proliferates± fibrinoid necrosis
→
HyperplasticOnion-skin; acute ischemia

Meanwhile the left ventricle works against higher afterload → concentric hypertrophy → stiff ventricle (diastolic dysfunction).

The three arterioscleroses

TYPE
LESION
SETTING
Atherosclerosis
Intimal plaque in large/medium arteries
Lipids, smoking, HTN, DM — page 7.06
Hyaline arteriolosclerosis
Pink glassy arteriolar wall
Benign HTN, diabetes, aging
Hyperplastic arteriolosclerosis
Onion-skin layers
Malignant HTN
Mönckeberg
Medial calcification
Older adults; non-obstructive

How it's tested

COMMON CONFUSIONDiabetes causes hyaline change in both afferent and efferent arterioles. Hypertension mostly affects the afferent arteriole.
THE TRAPVery high BP without organ damage is an urgency, treated with oral agents. Organ damage (papilledema, rising creatinine, confusion) makes it an emergency, treated with IV drugs and gradual lowering.
YOUR APPROACHYoung, abrupt, refractory or hypokalemic HTN → look for a secondary cause. Then read the arteriole: glassy = chronic, onion-skin = malignant.

If you see… think…

Young woman, HTN, abdominal bruit, "string of beads" → fibromuscular dysplasia
Older smoker, refractory HTN, creatinine rises on ACE inhibitor → bilateral renal artery stenosis
HTN + hypokalemia + low renin → primary aldosteronism
BP 230/130, headache, papilledema, AKI → hypertensive emergency
Onion-skin arterioles with fibrinoid necrosis → malignant hypertension
Small kidneys with finely granular surface → benign nephrosclerosis (hyaline)
Lacunar stroke in a hypertensive → lipohyalinosis of lenticulostriate arteries
Basal ganglia bleed in long-standing HTN → Charcot-Bouchard microaneurysm
Ring-calcified radial artery with normal lumen → Mönckeberg sclerosis