Pathology of Hypertension:,Dr. Venkatesh M. Shashidhar. Senior Lecturer in Pathology Fiji School of Medicine,Hypertension - Introduction,Silent Killer painless complications dizziness, headache, and visual difficulties, It is the leading risk factor MI, DM, Stroke Responsible 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 Resistance Endocrine Factors Renin, Angiotensin, ANP, ADH, Aldosterone. Neural Factors Sympathetic & Parasympathetic Blood Volume Sodium, Mineralocorticoids, ANP Cardiac Factors Heart rate & Contractility.,Control of Blood Pressure:,Blood Volume Na+, Aldosterone,Vasoconstrictors Angiotensin II Catecholamines,Vasodilators Pg & Kinins,Local Factors pH, Hypoxia,Neural Factors Adrenergic Cons Adrenergic - Dil,Cardiac Factors Rate & Contract,Humoral Factors,Etiologic Classification:,Primary or Essential Hypertension(95%) Secondary Hypertension (5-10%) Renal GN, RAS, Renin tumors Endocrine 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 - Multifactorial Increased 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 Retention Blood Volume,Aldosterone,Hypertension,Consequences of Hypertension:,Blood Vessels Atherosclerosis and its complications aneurism, Dissection, Rupture, necrosis. Arteriolosclerosis, Heart Hypertensive cardiomyopathy, IHD, MI. Kidney Benign/Malignant nephrosclerosis. Infarction Eyes: Hypertensive retinopathy Brain: Haemorrhage, infarction, splinter & Lacunar hemorrhages,Hyperplastic Arteriolosclerosis:,Onion Skin Thickening Of arterioles.,Narrow Lumen,Benign Nephrosclerosis:,Leathery Granularity due to minute scarring,Left Ventricular Hypertrophy:,Left Ventricular Hypertrophy,Cerebral Infarction (Stroke) :,Haemorrhagic Necrosis,Subarachnoid Haemorrhage:,Cerebral Blood vessels Special features: Thin walled* End arteries* Cong. Aneurisms,Lacunar Infarcts:,Chronic hypertension Arteriolosclerosis of deep penetrating arterioles of brain stem. Single or multiple cavitary infarcts lacunes. Lenticular nucleus, thalamus Slit Haemorrhages.,Renal Artery stenosis - Atrophy,Leathery Granularity Benign 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 failure Hypertensive encephalopathy. Left ventricular failure.,Necrotizing arteriolitis:,Fibrinoid Necrosis,Thrombosis,Conclusions:,Persistent increased blood pressure (140/90) 95% Essential, 5% secondary - Renovascular Benign and Malignant types (120Diastolic) Vessel damage & Arteriolosclerosis Complicates - Atherosclerosis, Diabetes, IHD Ischemia 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 and pathological features? What are lacunar infarcts? arteriolosclerosis? How does hptn causes stroke? Damage heart?,“Do what you love, love what you do, and deliver more than you promise” Harvey Mackay,