高血壓病理學

Pathologyof

Hypertension:Dr.VenkateshM.Shashidhar.SeniorLecturerinPathologyFijiSchoolofMedicineHypertension-IntroductionSilentKiller–painless–complicationsdizziness,headache,andvisualdifficulties,Itistheleadingriskfactor–MI,DM,StrokeResponsibleforthemajorityofofficevisits,Numberonereasonfordrugprescription.25%ofpopulation,<35%aware.<5%..!

Complicationsbringtodiagnosisbutlate…Chronic,vascular&endorgandamage.Introduction“Sustainedincreaseinbloodpressure”Systolic>140,Diastolic>90mmofHg*Normal*<130<85(120/80+/-10/5)Mild+20,Moderate+40Severe+80Malignant->210/120RegulationofBP:BP=CardiacOutputxPeripheralResistanceEndocrineFactorsRenin,Angiotensin,ANP,ADH,Aldosterone.NeuralFactorsSympathetic&ParasympatheticBloodVolumeSodium,Mineralocorticoids,ANPCardiacFactorsHeartrate&Contractility.ControlofBloodPressure:BPCardiacOutputPeripheralResistanceBloodVolumeNa+,AldosteroneVasoconstrictorsAngiotensinIICatecholaminesVasodilatorsPg&KininsLocalFactorspH,HypoxiaNeuralFactorsAdrenergic–Cons?Adrenergic-DilCardiacFactorsRate&Contract..HumoralFactorsEtiologicClassification:PrimaryorEssentialHypertension(95%)SecondaryHypertension(5-10%)Renal–GN,RAS,RenintumorsEndocrine–Cushing,OCP,ThyrotoxicosisMyxdema,Pheochromocytoma,Acromegaly.Vascular–CoarctationofAorta,PAN,Aorticinsufficiency.Neurogenic–Psychogenic,Intracranialpressure,olyneuritisetc.PathogenesisofHypertension:?PathogenesisinEssentialhypertension-MultifactorialIncreasedbloodvolume-SodumretentionADH,Aldosterone.Increasedsympathetictone-Adrenaltumours,sympatheticstimulation.Increasedvasoactivehormones-Cushings,Pheochromocytoma,PathogenesisofRenovascularHTN:

GFRReninbyJGAAngiotensinIIVasoconstriction

P.ResistanceSodiumRetention

BloodVolumeAldosteroneHypertensionConsequencesofHypertension:Blood

VesselsAtherosclerosisanditscomplicationsaneurism,Dissection,Rupture,necrosis.Arteriolosclerosis,HeartHypertensivecardiomyopathy,IHD,MI.KidneyBenign/Malignantnephrosclerosis.InfarctionEyes:HypertensiveretinopathyBrain:Haemorrhage,infarction,splinter&LacunarhemorrhagesHyperplasticArteriolosclerosis:OnionSkinThickeningOfarterioles.NarrowLumenBenign

Nephrosclerosis:LeatheryGranularityduetominutescarringLeftVentricularHypertrophy:LeftVentricularHypertrophyCerebralInfarction(Stroke):HaemorrhagicNecrosisSubarachnoidHaemorrhage:CerebralBloodvesselsSpecialfeatures:Thinwalled*Endarteries*Cong.AneurismsLacunarInfarcts:ChronichypertensionArterioloscleros