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.
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
Regulation of BP:
BP = Cardiac Output x Peripheral Resistance Endocrine Factors
Renin, Angiotensin, ANP, ADH, Aldosterone.
Neural Factors
Sympathetic & Parasympathetic
Lacunar Infarcts:
Chronic hypertension Arteriolosclerosis of deep penetrating arterioles of brain stem. Single or multiple cavitary infarcts – lacunes. Lenticular nucleus, thalamus Slit Haemorrhages.
Necrotizing arteriolitis:
Thrombosis
Fibrinoid Necrosis
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.
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,
“Do what you love, love what you do, and deliver more than you promise”
– Harvey Mackay
Hyperplastic Arteriolosclerosis:
Narrow Lumen
Onion Skin Thickening Of arterioles.
Benign Nephrosclerosis:
Leathery Granularity due to minute scarring
Left Ventricular Hypertrophy:
Pathogenesis of Renovascular HTN: GFR Renin by JGA Aldosterone
Sodium Retention Blood Volume
Hypertension
Angiotensin II
Vasoconstriction P. Resistance
Introduction
“Sustained increase in blood pressure” Systolic >140, Diastolic > 90 mm of Hg* Normal* < 130 <85 (120/80 +/- 10/5) Mild + 20, Moderate +40 Severe +80 Malignant - > 210/120
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
Blood Volume Na+, Aldosterone
Vasodilators Pg & Kinins
BP
Cardiac Factors Rate & Contract..
Cardiac Otance
Local Factors pH, Hypoxia
Neural Factors Adrenergic – Cons ßAdrenergic - Dil
Left Ventricular Hypertrophy
Cerebral Infarction (Stroke) :
Haemorrhagic Necrosis
Subarachnoid Haemorrhage:
Cerebral Blood vessels Special features: Thin walled* End arteries* Cong. Aneurisms
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. <5% ..! Complications bring to diagnosis but late… Chronic, vascular & end organ damage.
Blood Volume
Sodium, Mineralocorticoids, ANP
Cardiac Factors
Heart rate & Contractility.
Control of Blood Pressure:
Vasoconstrictors Angiotensin II Catecholamines Humoral Factors
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?