Hypertension, PVD, and Stroke Flashcards
Hypertension definition
systolic > 140; diastolic > 90
Types of hypertension
benign: most common, stable course
malignant (5%): rapidly rising BP with accelerated renal failure; retinal hemorrhagic exudates +/- papilledema; diastolic >120
Regulation of blood pressure is a function of
cardiac output and peripheral resistance - if either of those increase, BP also increases
Hypertension is an altered relationship between
blood volume and total arteriolar resistance
Vasoconstrictors
angiotensin II, catecholamines, thromboxane, leukotrienes, endothelin, lactic acid, hydrogen ions, adenosine, hypoxia
Vasodilators
kinins, prostaglandins, nitric oxide
Atriopeptin
secreted by heart atria in response to volume expansion; leads to decrease in Na resorption
Renal vasodepressor substances
counterbalance vasopressor response of angiotensin
Essential hypertension
increased cardiac output +/- increased peripheral resistance
Possible causes of increase in cardiac output
genetic defect in renal sodium excretion; inherited heterogeneity in the renin-angiotensin system; decreased perfusion of kidneys which leads to volume expansion (as in CHF)
Possible causes of increase in peripheral resistance
behavioral or neurogenic; increased release of vasoconstrictive agents (renin, catecholamine, endothelin); increased sensitivity of smooth muscle to vasoconstrictor effects
Environmental factors in hypertension
stress, obesity, smoking, inactivity, heavy consumption of salt (augments HTN)
Hyaline arteriolosclerosis
elderly patients, diabetes; leakage of plasma components, increased extracellular matrix in SM layers; homogeneous, pink, hyaline thickening of walls of arterioles with narrowing of lumon
Benign nephrosclerosis
hyaline arteriolosclerosis in the kidney
Hyperplastic arteriolosclerosis
more acute or severe elevations of blood pressure; characteristic of malignant hypertension with diastolic pressures >110; onionskin, concentric laminated thickening of the walls of the arterioles
Hyperplastic arteriolosclerosis may be associated with
fibrinoid and acute necrosis - necrotizing arteriolitis
onionskin, concentric laminated thickening of the walls of the arterioles; narrowing of the lumen; thickened basement membrane
Hyperplastic arteriolosclerosis
Chronic ischemia of the coronary arteries causes
CHF; subendothelial infarcts
Intermittent hypoperfusion of the coronary arteries causes
angina
Infarction of the coronary arteries causes
transmural myocardial infarction
chronic ischemia of the carotid arteries causes
cerebral atrophy; organic brain syndrome
Intermittent hypoperfusion of the carotid arteries causes
transient ischemic attacks
Intermittent hypoperfusion of the femoral artery causes
claudication
Infarction of the femoral artery causes
gangrene
