高血压病理学

Pathology of Hypertension:,Dr. Venkatesh M. Shashidhar.Senior Lecturer in PathologyFiji School of Medicine,Hypertension - Introduction,Silent Killer painless complicationsdizziness, headache, and visual difficulties,It is the leading risk factor MI, DM, StrokeResponsible for the majority of office visits, Number one reason for drug prescription.25% of population, 35% aware. 140, Diastolic 90 mm of Hg*Normal* 210/120,Regulation of BP:,BP = Cardiac Output x Peripheral ResistanceEndocrine FactorsRenin, Angiotensin, ANP, ADH, Aldosterone.Neural FactorsSympathetic & ParasympatheticBlood VolumeSodium, Mineralocorticoids, ANPCardiac FactorsHeart rate & Contractility.,Control of Blood Pressure:,Blood VolumeNa+, Aldosterone,VasoconstrictorsAngiotensin IICatecholamines,VasodilatorsPg & Kinins,Local FactorspH, Hypoxia,Neural FactorsAdrenergic Cons Adrenergic - Dil,Cardiac FactorsRate & Contract.,Humoral Factors,Etiologic Classification:,Primary or Essential Hypertension(95%)Secondary Hypertension (5-10%)Renal GN, RAS, Renin tumorsEndocrine Cushing, OCP, Thyrotoxicosis Myxdema, Pheochromocytoma, Acromegaly.Vascular Coarctation of Aorta, PAN, Aortic insufficiency.Neurogenic Psychogenic, Intracranial pressure, olyneuritis etc.,Pathogenesis of Hypertension:,? Pathogenesis in Essential hypertension - MultifactorialIncreased blood volume - Sodum retention ADH, Aldosterone.Increased sympathetic tone - Adrenal tumours, sympathetic stimulation.Increased vasoactive hormones - Cushings, Pheochromocytoma,Pathogenesis of Renovascular HTN:,GFR,Renin by JGA,Angiotensin II,Vasoconstriction P. Resistance,Sodium RetentionBlood Volume,Aldosterone,Hypertension,Consequences of Hypertension:,Blood VesselsAtherosclerosis and its complications aneurism, Dissection, Rupture, necrosis. Arteriolosclerosis, HeartHypertensive cardiomyopathy, IHD, MI.KidneyBenign/Malignant nephrosclerosis. InfarctionEyes: Hypertensive retinopathyBrain: Haemorrhage, infarction, splinter & Lacunar hemorrhages,Hyperplastic Arteriolosclerosis:,Onion Skin ThickeningOf arterioles.,Narrow Lumen,Benign Nephrosclerosis:,Leathery Granularity due to minute scarring,Left Ventricular Hypertrophy:,Left Ventricular Hypertrophy,Cerebral Infarction (Stroke) :,HaemorrhagicNecrosis,Subarachnoid Haemorrhage:,Cerebral Blood vesselsSpecial features:Thin walled*End arteries*Cong. Aneurisms,Lacunar Infarcts:,Chronic hypertensionArteriolosclerosis of deep penetrating arterioles of brain stem.Single or multiple cavitary infarcts lacunes.Lenticular nucleus, thalamusSlit Haemorrhages.,Renal Artery stenosis - Atrophy,Leathery GranularityBenign Nephrosclerosis,Normal Retina - Fundoscopy,Hypertensive Retinopathy:,Grade I Thickening of arterioles.Grade II Focal Arteriolar spasms. Vein constriction.Grade III Hemorrhages (Flame shape), dot-blot and Cotton wool and hard waxy exudates.Grade IV - Papilloedema,Malignant Hypertension:,May complicate any type of HTN.Necrotizing arteriolitis.Intravascular thrombosis.Rapidly progressive end organ damage.Renal failureHypertensive encephalopathy. Left ventricular failure.,Necrotizing arteriolitis:,Fibrinoid Necrosis,Thrombosis,Conclusions:,Persistent increased blood pressure (140/90)95% Essential, 5% secondary - RenovascularBenign and Malignant types (120Diastolic)Vessel damage & Arteriolosclerosis Complicates - Atherosclerosis, Diabetes, IHDIschemia or Infarction in end organs.Kidney, Brain, Heart & Eyes.Nephrosclerosis, renal damage, IHD, MI, Stroke & Retinopathy.,Self Assessment Questions:,Define essential, hypertension?Briefly describe pathogenesis of renal damage in hypertension.Classify hypertension, briefly describe pathogenesis in each?Summarize common complications of hptn?What is nephrosclerosis? Briefly describe its pathogenesis?What is meant by malignant hypertension? Briefly describe clinical