HYPERTENSIVE VASCULAR DISEASE - JU Medicine...2018/01/05 · HYPERTENSIVE VASCULAR DISEASE...
Transcript of HYPERTENSIVE VASCULAR DISEASE - JU Medicine...2018/01/05 · HYPERTENSIVE VASCULAR DISEASE...
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HYPERTENSIVEVASCULARDISEASE
Arteriolosclerosis
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Hypertension(HTN)
• Cutoffsindiagnosinghypertensioninclinicalpracticeè sustaineddiastolicpressures>90mmHg,and/orsustainedsystolicpressures>140mmHg
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• Malignanthypertensionà 5%ofHTNpatientspresentwitharapidlyrisingbloodpressurethat,ifuntreated,leadstodeathwithin1to2years.è systolicpressures>200mmHgordiastolicpressures>120mmHgà associatedwithrenalfailureandretinalhemorrhagesàmostcommonlyissuperimposedonpreexistingbenignhypertension
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Hypertension(HTN)hasthefollowingpotentialcomplications:
• stroke(CVD)• multi-infarctdementia• atheroscleroticcoronaryheartdisease• cardiachypertrophyandheartfailure(hypertensiveheartdisease)
• aorticdissection• renalfailure
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Typesofhypertension
1- essential(idiopathic)hypertension (95%)2- secondaryhypertension:Mostareduetorenaldisease,orrenalarterynarrowing
(=renovascular hypertension),andtoalesserdegreeareduetomanyotherconditions….
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1- EssentialHTNAccountsfor90%to95%ofallcases
2- Secondary HTN:
Renal(mostcommonofsecondary)AcuteglomerulonephritisChronicrenaldiseasePolycysticdiseaseRenalarterystenosisRenalvasculitisRenin-producingtumors
EndocrineAdrenocortical hyperfunction (Cushingsyndrome,primaryaldosteronism,CAHlicoriceingestion)Exogenoushormones(glucocorticoids,estrogensympathomimeticsmonoamineoxidase inhibitors)PheochromocytomaAcromegalyHypothyroidism(myxedema)Hyperthyroidism(thyrotoxicosis)Pregnancy-induced(pre-eclampsia)
CardiovascularCoarctation ofaortaPolyarteritis nodosaIncreasedintravascularvolumeIncreasedcardiacoutputRigidityoftheaorta
NeurologicPsychogenicIncreasedintracranialpressureSleepapneaAcutestress,includingsurgery
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• Pathogenesisofessential HTN• ?Geneticfactors• ?familialclusteringofhypertension• angiotensinogen polymorphismsandangiotensin IIreceptorvariants;polymorphismsoftherenin-angiotensin system.
• ?Susceptibilitygenesforessentialhypertension:genesthatcontrolrenalsodiumabsorption,etc.
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PathogenesisofessentialHTN
• Environmentalfactors• stress,obesity,smoking,physicalinactivity,andhighlevelsofsaltconsumption,modifytheimpactofgeneticdeterminants.
• Evidencelinkingdietarysodiumintakewiththeprevalenceofhypertensionindifferentpopulationgroupsisparticularlystrong.
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Morphology
• HTNisassociatedwitharteriolosclerosis(smallarterialdisease)
• Twoformsofsmallbloodvesseldiseasearehypertension-related:
1- hyalinearteriolosclerosis2- hyperplastic arteriolosclerosis
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1- Hyalinearteriolosclerosis• withbenign hypertension.• homogeneous,pinkhyalinethickeningofthearteriolarwalls;luminalnarrowing.
• leakageofplasmacomponentsacrossinjuredendothelialcells intovesselwallsandincreasedECMproductionbysmoothmusclecellsinresponsetochronichemodynamicstress.
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• Hyalinearteriolosclerosis:Complications- Mostsignificantinkidneysènephrosclerosis (glomerularscarring).
• Othercauseshyaline arteriolosclerosis:1- elderlypatients(normo-tensive)2- diabetis mellitus
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2- Hyperplastic arteriolosclerosis
• Withsevere(malignant) hypertension.• "onionskin"concentriclaminatedthickeningofarteriolarwallsàluminal narrowing.
• =smoothmusclecellsandthickened,reduplicatedbasementmembrane.
• Inmalignanthypertensionà fibrinoid vesselwallnecrosis(necrotizingarteriolitis),whichareparticularlyprominentinthekidney
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A,Hyalinearteriolosclerosis.Thearteriolarwallisthickenedwiththedepositionofamorphousproteinaceous material,andthelumenismarkedlynarrowed.B,Hyperplastic arteriolosclerosis("onion-skinning")(arrow)causingluminalobliteration
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EDEMA
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EDEMA 60% of lean body wt. = water
à(2/3) intracellular. à(1/3) extracellular (interstitial fluid) waterà5% blood plasma.
edema = accumulation of interstitial fluid within tissues.
Edema ≠ Extravascular fluid collection in body cavities:- pleural cavity (hydrothorax)- the pericardial cavity (hydropericardium)- peritoneal cavity (hydroperitoneum, or ascites).
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Increased Hydrostatic PressureImpaired Venous ReturnCongestive heart failure; Constrictive pericarditis; Ascites (liver cirrhosis); Venous obstruction or compression; Thrombosis; External pressure (e.g., mass); Lower extremity inactivity with prolonged dependency
Arteriolar DilationHeat; Neurohumoral dysregulation
Reduced Plasma Osmotic Pressure (Hypoproteinemia)Protein-losing glomerulopathies (nephrotic syndrome)Liver cirrhosis (ascites); Malnutrition; Protein-losing gastroenteropathy
Lymphatic ObstructionInflammatory; Neoplastic; Postsurgical; Postirradiation
Sodium RetentionExcessive salt intake with renal insufficiencyIncreased tubular reabsorption of sodium
Renal hypoperfusionIncreased renin-angiotensin-aldosterone secretion
InflammationAcute inflammation; Chronic inflammation; Angiogenesis
Mechanisms of edema
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Clinical Correlation of edema Subcutaneous edema: - the most common; - important to recognize as it signals potential underlying cardiac or
renal disease- Can impair wound healing or the clearance of infections. ------------- --------- ---------- Brain edema: - life-threateningà brain herniation (extrude) e.g. through the
foramen magnum.
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Pulmonary edema: ØCommon causes:- left ventricular failure - renal failure - ARDS- inflammatory and infectious disorders of the lung. Øcan cause death by interfering with normal ventilatory
function & impeding oxygen diffusionØcreates a favorable environment for infections