Pathology of Systemic Hypertension

Comprehensive question-and-answer practice flashcards covering systemic essential, secondary, and malignant hypertension, along with associated vascular, renal, cardiac, CNS, and ocular pathology.

Who is the lecturer for the pathology of systemic hypertension lecture notes?

Dr H-T Wu

Which academic and hospital departments are associated with the systemic hypertension lecture notes?

Anatomical Pathology, UCT / NHLS-GSH

What blood pressure threshold defines systemic hypertension?

Systemic blood pressure $≥ 140 / 90\,mmHg$

What percentage of the population is affected by systemic hypertension?

25% of population

Systemic hypertension is the most important risk factor for which two cardiovascular and cerebrovascular conditions?

Coronary artery disease and CVAs (cerebrovascular accident = "stroke")

What percentage of systemic hypertension cases are classified as essential (idiopathic / benign) hypertension?

90%

What is the pathogenic sequence initiated by genetic and hypertensinogenic factors in essential hypertension?

Genetic + Hypertensinogenic factors $→$ $\downarrow\text{Na}^+$ (sodium) excretion $→$ $\uparrow\text{volume}$ $→$ $\uparrow\text{vascular tone}$ $→$ chronic vasoconstriction

What specific physiological characteristics related to hypertension are noted in individuals of African descent?

Low renin, smaller kidneys, and salt-sensitivity

Is obesity listed as a risk factor for essential hypertension?

Yes, obesity is a hypertensinogenic risk factor for essential hypertension.

Is smoking listed as a risk factor for essential hypertension?

Yes, smoking is a risk factor for essential hypertension.

What dietary factor regarding sodium increases the risk for essential hypertension?

High sodium diet

What threshold of alcohol consumption is identified as a risk factor for essential hypertension?

3 or more drinks per day (3+ drinks/day)

Is stress listed as a risk factor for essential hypertension?

Yes, stress is listed as a risk factor for essential hypertension.

What level of physical activity is associated with essential hypertension?

Physical inactivity

Which metabolic disturbance related to glucose regulation is listed as a risk factor for essential hypertension?

Insulin resistance

What percentage of systemic hypertension cases are classified as secondary hypertension?

10%

What are the two primary mechanisms by which renal disorders cause secondary hypertension?

Increased renin ($\uparrow\text{renin}$) and fluid retention

Which renal cystic disease is specifically cited as a renal cause of secondary hypertension?

Adult polycystic kidney disease

Besides parenchymal diseases and cysts, what other renal causes can lead to secondary hypertension?

Renin-secreting tumours and obstructive uropathy

What two underlying vascular etiologies cause renal artery stenosis leading to secondary hypertension?

Atherosclerosis and fibromuscular dysplasia

Which congenital aortic abnormality is listed as a cardiovascular cause of secondary hypertension?

Co-arctation (of aorta)

Which systemic necrotizing vasculitis is listed as a cardiovascular cause of secondary hypertension?

Polyarteritis nodosa

What specific pituitary tumor causes Cushing disease leading to secondary hypertension?

ACTH secreting pituitary adenoma

What state of corticosteroid excess defines Cushing syndrome as an endocrine cause of secondary hypertension?

Hypercortisolism

What state of adrenal hormone excess defines Conn syndrome?

Hyperaldosteronism

What is a phaeochromocytoma and what hormones does it secrete?

A tumour of the adrenal medulla that releases adrenaline and noradrenaline

Which thyroid conditions are listed as potential endocrine causes of secondary hypertension?

Hyperthyroidism and hypothyroidism (hyper/ hypothyroid)

Which pituitary-related growth hormone disorder causes secondary hypertension?

Acromegaly

Which electrolyte disturbance is listed as an endocrine cause of secondary hypertension?

Hypercalcaemia

What three features characterize pregnancy-induced hypertension?

Hypervolaemia, physiologic tachycardia, and abnormal modelling of maternal vessels

What dosage level of oestrogens is linked to secondary hypertension?

High-dose oestrogens

Are steroid drugs listed as a cause of secondary hypertension?

Yes, steroids are listed as a cause of secondary hypertension.

Which class of anti-inflammatory drugs can induce secondary hypertension?

Nonsteroidal anti-inflammatory agents

Are nasal or systemic decongestants identified as drug causes of secondary hypertension?

Yes, decongestants are listed as a drug cause of secondary hypertension.

Can appetite suppressants cause secondary hypertension?

Yes, appetite suppressants are listed as a cause of secondary hypertension.

Which two specific classes of antidepressant medications are noted to cause secondary hypertension?

Tricyclic antidepressants and monamine oxidase inhibitors

Which immunosuppressive agent used in transplantation can cause secondary hypertension?

Cyclosporine

Which hematopoietic agent used to stimulate erythropoiesis causes secondary hypertension?

Erythropoietin

Which illicit stimulant is explicitly named as a drug cause of secondary hypertension?

Cocaine

Which confectionary item/plant extract can cause secondary hypertension when consumed in excess?

Liquorice

Which respiratory sleep disorder is a neurogenic cause of secondary hypertension?

Obstructive sleep apnoea

What are two specific clinical examples of stress-induced neurogenic hypertension listed in the notes?

White coat hypertension and intubation during anaesthesia

Which peripheral neuropathic condition is listed as a neurogenic cause of secondary hypertension?

Polyneuritis

What acute intracranial pressure change causes secondary neurogenic hypertension?

Acute raised intracranial pressure

What acute spinal cord injury leads to secondary neurogenic hypertension?

Acute spinal cord transection

How is malignant (accelerated) hypertension defined?

Abrupt marked increase in BP (diastolic $>120\,mmHg$, systolic $>200\,mmHg$) leading to end organ damage

What percentage of hypertensive patients develop malignant hypertension?

1–5% of hypertensive patients

Which population demographic is predominantly affected by malignant hypertension?

Young men of African ancestry

On what underlying pre-existing conditions is malignant hypertension most commonly superimposed?

Essential HPT, chronic renal disease (esp glomerulonephritis / reflux nephropathy), or scleroderma

Can a patient developing malignant hypertension have been previously normotensive?

Yes, patients may be previously normotensive.

What specific vascular lesion is directly induced by severe blood pressure elevation in malignant HPT?

Necrotising arteriolitis with fibrinoid necrosis

What are the steps of the vicious cycle seen in malignant hypertension?

Severe hypertension $→$ necrotising arteriolitis with fibrinoid necrosis $→$ renal ischaemia $→$ activation of renin-angiotensin system $→$ $\uparrow\text{BP}$ $→$ necrotising arteriolitis

What histological arteriolar change is characteristic of benign hypertension?

Hyaline arteriolosclerosis

What histological arteriolar changes are characteristic of malignant hypertension?

Hyperplastic arteriolosclerosis $\pm$ fibrinoid necrosis

What three pathological changes occur in muscular arteries due to systemic hypertension?

Intimal fibrosis, medial hypertrophy, and hyalinization

What two major vascular complications occur in large arteries as a result of systemic hypertension?

Aortic dissection and accelerated atherosclerosis

What is the defining anatomical mechanism of an aortic dissection?

Blood enters aortic media through an intimal tear & splays it apart to form a channel

What percentage of aortic dissection cases are caused by hypertension?

90%

Besides hypertension, what other causes of aortic dissection are listed?

Marfan's syndrome, trauma, and iatrogenic causes

What are the typical clinical pain characteristics of an aortic dissection?

Sudden pain in anterior chest radiating to back & moving down

What four main complications historically caused death in aortic dissection?

Tamponade, aortic regurgitation, myocardial infarction, and massive haemorrhage

What is the survival rate for aortic dissection with rapid diagnosis, intensive antihypertensive medication, and surgical plication?

65% to 75% survive

In which patient groups is benign nephrosclerosis typically observed?

Elderly patients, patients with hypertension, or patients with diabetes mellitus (DM)

Why does the kidney have a granular capsular surface in benign nephrosclerosis?

Due to glomeruli being shrunken and replaced by fibrosis

How does arteriolar involvement in hyaline arteriolosclerosis differ between hypertension and diabetes mellitus?

In hypertension, hyaline arteriolosclerosis involves afferent (but not efferent) arterioles; in diabetes, efferent arterioles are also involved.

What is the usual severity of renal impairment in benign nephrosclerosis?

Usually mild renal impairment

Is renal failure common in benign nephrosclerosis?

No, renal failure is rare.

Under what specific clinical conditions does renal failure occur in benign nephrosclerosis?

African descent, severe hypertension, DM, or superimposed malignant HPT

What is the direct underlying cause of malignant nephrosclerosis?

Malignant hypertension

What renal clinical signs and urinalysis findings characterize malignant nephrosclerosis?

Renal failure, proteinuria, and haematuria

Describe the gross anatomical appearance of the kidney in malignant nephrosclerosis.

Swollen "flea-bitten" kidney due to petechial haemorrhages

What combination of microscopic vascular changes is seen in malignant nephrosclerosis?

Hyperplastic arteriolosclerosis + fibrinoid necrosis

What ocular signs occur in other organs during malignant hypertension?

Retinal haemorrhage $\pm$ papilloedema

What central nervous system clinical presentation occurs in malignant hypertension?

Encephalopathy (severe headache $\pm$ haemorrhage)

What acute pulmonary and cardiac complication is caused by malignant hypertension?

Acute LVF (left ventricular failure) with pulmonary oedema

What is the 1-year mortality rate of malignant hypertension if left untreated?

90% mortality in 1 year if no treatment (no Rx)

What is the 5-year survival rate of malignant hypertension when treated?

75% 5-year survival

In hypertensive heart disease, what cellular change in myocytes occurs due to increased load?

Myocyte hypertrophy

How does myocyte hypertrophy affect oxygen consumption and tissue perfusion?

It leads to $\uparrow\text{O}_2$ consumption and $\downarrow\text{perfusion}$

What pattern of ventricular hypertrophy is seen in hypertensive heart disease?

Concentric left ventricular hypertrophy

What left ventricular wall thickness measurement indicates left ventricular hypertrophy in hypertensive heart disease?

LV $>15\,mm$ thick

Does ventricular dilatation occur in concentric left ventricular hypertrophy?

No dilatation occurs unless left ventricular failure develops.

Why does the left atrium enlarge in hypertensive heart disease?

Because the stiff left ventricle impairs diastolic filling.

What characteristic morphological feature is seen in the nuclei of hypertrophied cardiac myocytes?

"Box-car" shaped nuclei

Can hypertensive heart disease be clinically asymptomatic?

Yes, it can present as asymptomatic.

Which specific cardiac arrhythmia is listed as a clinical complication of hypertensive heart disease?

Atrial fibrillation

In which specific hypertensive state is acute left ventricular failure characteristically seen?

Malignant HPT

Is congestive cardiac failure a outcome of hypertensive heart disease?

Yes, congestive cardiac failure is a recognized clinical presentation.

How does malignant hypertension affect underlying coronary artery disease?

Malignant HPT exacerbates coronary artery disease and potentiates it.

What sudden fatal event can occur in hypertensive heart disease due to spontaneous arrhythmia?

Sudden cardiac death

What morphological type of aneurysm is a Berry aneurysm?

Saccular aneurysm

Where are Berry aneurysms primarily located in the cerebral vasculature, and what percentage are anterior?

Circle of Willis (90% anterior)

Is the multiplicity of Berry aneurysms associated with systemic hypertension?

Yes, multiplicity of Berry aneurysms is associated with hypertension.

Besides hypertension, what two conditions are associated with Berry aneurysms?

Marfan's syndrome and autosomal dominant polycystic kidney disease

What is the diameter definition of Charcot-Bouchard microaneurysms?

Microaneurysm $<300\,\mu m$ in diameter

What are the two primary central nervous system sites for Charcot-Bouchard microaneurysms?

Basal ganglia and brainstem

What structural shape defines atheromatous aneurysms in the CNS?

Fusiform aneurysms

Which cerebral artery is specifically listed as a site for atheromatous aneurysms?

Basilar artery

What major cerebrovascular accident (CVA) results directly from intracerebral haemorrhage in hypertension?

Haemorrhagic CVA

Besides main intracerebral haemorrhages, what smaller vascular lesions occur in hypertensive brain injury?

Small slit haemorrhages