Hypertension Robbins: 525 to 530, Cecil:

Hypertensive Vascular Disease HTN risk factor for: Coronary heart disease Stroke LVH with heart failure Aortic dissection Renal failure

Hypertension Sustained: Diastolic > 90 (some >80) Systolic > 140 See table 13-8 in Cecil Essentials Normal<120And<80 Prehypertension Or80-89 Stage Or80-90 Stage 2>160Or>100

Causes of Hypertension 90-95% idiopathic 5-10% 2° to renal disease or renovascular hypertension All other causes rare

Accelerated (Malignant) hypertension Severe hypertension (diastolic >120mmHg) Renal failure Retinal hemorrhages with papilledema Seizures Strokes DIC

Normal Blood Pressure Cardiac output Na homeostasis Total peripheral resistance Lumen size Neural and hormonal influences that constrict or dilate these vessels

Kidney Renin-produced by the JG cells of the kidney Transforms plasma angiotensinogen to angiotensin I Angiotensin I converted to angiotensin II by ACE Angiotensin II increases peripheral resistance and blood volume

The Kidney Produces Vasodepressor Substances Prostaglandins Kallikrein-kinin Platelet-activation factor Nitric oxide

Blood volume reduced Glomerular filtration rate falls Increased reabsorption of Na Leads to conserve Na and expand blood volume

GFR-independent Natruretic Factors Atrial natriuretic factor (ANF) Inhibits Na reabsorpton in distal tubules Cause vasodilatation

Essential hypertension Alter the relationship between volume and total peripheral resistance

Renovascular hypertension Renal artery stenosis causes deceased glomerular flow Induces renin secretion Induces angiotensin II-induced vasoconstriction Increased peripheral resistance Aldosterone causes increased sodium reabsorption and inceased blood volume

Genetic factors Environmental factors Salt, stress, smoking Obesity, physical inactivity

Mechanisms Renal retention of excess sodium Vasoconstriction and vascular hypertrophy Thickened wall Narrowed lumen

Vascular pathology Hyaline Arteriolosclerosis Hyalinized walls with narrowed lumen Hyperplastic arteriosclerosis Concentric, laminated thickening of wall (onion-skin) Progressive narrowing of the lemen Necrotizing arteriolitis-fibroid necrosis

Hyaline arteriosclerosis

Hyperplastic arteriosclerosis - malignant hypertension