4. HypertensionHypertension
Elevated blood pressureElevated blood pressure
SustainedSustained diastolicdiastolic pressure greater thanpressure greater than 90 mm Hg90 mm Hg, or a, or a
sustainedsustained systolicsystolic pressure in excess ofpressure in excess of 140 mm Hg140 mm Hg..
systolic blood pressure is more important in determiningsystolic blood pressure is more important in determining
cardiovascular riskcardiovascular risk
Hypertension is a common health problem with occasionallyHypertension is a common health problem with occasionally
devastating outcomesdevastating outcomes
It typically remains asymptomatic until late in its course.It typically remains asymptomatic until late in its course.
5. HypertensionHypertension
Elevated blood pressureElevated blood pressure
It contributes to the pathogenesis of coronary heart diseaseIt contributes to the pathogenesis of coronary heart disease
and cerebrovascular accidents, cardiac hypertrophy andand cerebrovascular accidents, cardiac hypertrophy and
heart failure (heart failure (hypertensive heart diseasehypertensive heart disease), aortic dissection,), aortic dissection,
and renal failure.and renal failure.
The mechanisms of hypertension in the vast majority ofThe mechanisms of hypertension in the vast majority of
people remain unknown; "people remain unknown; "essential hypertensionessential hypertension“ .“ .
The prevalence and vulnerability to complications increaseThe prevalence and vulnerability to complications increase
with age; they are also higher in African Americans.with age; they are also higher in African Americans.
Reduction of blood pressure dramatically reduces theReduction of blood pressure dramatically reduces the
incidence and death rates from IHD, heart failure, andincidence and death rates from IHD, heart failure, and
strokestroke
6. Pathogenesis of HypertensionPathogenesis of Hypertension
Ninety percent to 95% of hypertension is idiopathicNinety percent to 95% of hypertension is idiopathic
((essential hypertensionessential hypertension), which is compatible with long life,), which is compatible with long life,
unless complication supervenes.unless complication supervenes.
Most of the remainder of "Most of the remainder of "benign hypertensionbenign hypertension" is" is
secondary to renal disease or, narrowing of renal artery,secondary to renal disease or, narrowing of renal artery,
(atheromatous plaque, renovascular hypertension).(atheromatous plaque, renovascular hypertension).
Infrequently, hypertension is secondary to diseases of theInfrequently, hypertension is secondary to diseases of the
adrenal glands, such as primary aldosteronism. Cushingadrenal glands, such as primary aldosteronism. Cushing
syndrome, pheochromocytoma, or other disorders.syndrome, pheochromocytoma, or other disorders.
7. Pathogenesis of HypertensionPathogenesis of Hypertension
About 5% of hypertensive persons show a rapidly risingAbout 5% of hypertensive persons show a rapidly rising
blood pressure that if untreated leads to death within 1 or 2blood pressure that if untreated leads to death within 1 or 2
years.years.
TermedTermed acceleratedaccelerated oror malignant hypertensionmalignant hypertension,,
The clinical syndrome is characterized by severeThe clinical syndrome is characterized by severe
hypertension (diastolic pressure overhypertension (diastolic pressure over 120mmHg120mmHg),), renalrenal
failure, and retinal hemorrhages and exudates, with orfailure, and retinal hemorrhages and exudates, with or
without papilledema (swelling of the optic disc).without papilledema (swelling of the optic disc).
It may develop in previously normotensive persons butIt may develop in previously normotensive persons but
more often is superimposed on preexisting benignmore often is superimposed on preexisting benign
hypertension, either essential or secondary.hypertension, either essential or secondary.
8. Types and CausesTypes and Causes
of Hypertensionof Hypertension
(Systolic and(Systolic and
Diastolic)Diastolic)
Essential Hypertension (90% to 95% of Cases)Essential Hypertension (90% to 95% of Cases)
Secondary HypertensionSecondary Hypertension
RENALRENAL
Acute glomerulonephritisAcute glomerulonephritis
Chronic renal diseaseChronic renal disease
Polycystic diseasePolycystic disease
Renal artery stenosisRenal artery stenosis
Renal vasculitisRenal vasculitis
Renin-producing tumorsRenin-producing tumors
ENDOCRINEENDOCRINE
Adrenocortical hyperfunction (Cushing syndrome, primary Adrenocortical hyperfunction (Cushing syndrome, primary
aldosteronism, congenital adrenal hyperplasia, licorice aldosteronism, congenital adrenal hyperplasia, licorice
ingestion)ingestion)
Exogenous hormones (glucocorticoids, estrogen [including Exogenous hormones (glucocorticoids, estrogen [including
pregnancy-induced and oral contraceptives], pregnancy-induced and oral contraceptives],
sympathomimetics and tyramine-containing foods, sympathomimetics and tyramine-containing foods,
monoamine oxidase inhibitors)monoamine oxidase inhibitors)
PheochromocytomaPheochromocytoma
AcromegalyAcromegaly
Hypothyroidism (myxedema)Hypothyroidism (myxedema)
Hyperthyroidism (thyrotoxicosis)Hyperthyroidism (thyrotoxicosis)
Pregnancy-inducedPregnancy-induced
CARDIOVASCULARCARDIOVASCULAR
Coarctation of aortaCoarctation of aorta
Polyarteritis nodosaPolyarteritis nodosa
Increased intravascular volumeIncreased intravascular volume
Increased cardiac outputIncreased cardiac output
Rigidity of the aortaRigidity of the aorta
NEUROLOGICNEUROLOGIC
PsychogenicPsychogenic
Increased intracranial pressureIncreased intracranial pressure
Sleep apneaSleep apnea
Acute stress, including surgeryAcute stress, including surgery
9. Essential HypertensionEssential Hypertension
contributing factorscontributing factors
Alterations in Alterations in renal sodium renal sodium homeostasis and/or homeostasis and/or vessel wall vessel wall
tone or structure tone or structure underlie essential hypertensionunderlie essential hypertension
Both increased Both increased blood volume blood volume and increased and increased peripheral peripheral
resistanceresistance contribute to the increased pressure. contribute to the increased pressure.
10. Essential HypertensionEssential Hypertension
Essential hypertension results from an interplay of multiple Essential hypertension results from an interplay of multiple
geneticgenetic and and environmentalenvironmental factors affecting factors affecting cardiac output cardiac output
and/or and/or peripheral resistanceperipheral resistance. .
Genetic factorsGenetic factors: Allelic variations in the genes encoding : Allelic variations in the genes encoding
components of the renin-angiotensin system.components of the renin-angiotensin system.
Hypertension is associated with polymorphisms in Hypertension is associated with polymorphisms in
both the angiotensinogen locus and the angiotensin II both the angiotensinogen locus and the angiotensin II
type I receptor locus. type I receptor locus.
Environmental factorsEnvironmental factors: modify the expression of any : modify the expression of any
underlying genetic determinants of hypertension; stress, underlying genetic determinants of hypertension; stress,
obesity, smoking, physical inactivity, and heavy obesity, smoking, physical inactivity, and heavy
consumption of salt are all implicated. consumption of salt are all implicated.
11.
12. Vascular Pathology in HypertensionVascular Pathology in Hypertension
In addition to accelerating atherogenesis, hypertension-In addition to accelerating atherogenesis, hypertension-
associated degenerative changes in the walls of large and associated degenerative changes in the walls of large and
medium arteries can potentiate both aortic dissection and medium arteries can potentiate both aortic dissection and
cerebrovascular hemorrhage. cerebrovascular hemorrhage.
Hypertension is also associated with two forms of small Hypertension is also associated with two forms of small
blood vessel disease: blood vessel disease:
Hyaline arteriolosclerosis Hyaline arteriolosclerosis
Hyperplastic arteriolosclerosis Hyperplastic arteriolosclerosis
13. HyalineHyaline ArteriolosclerosisArteriolosclerosis
Characterized by Characterized by
Diffuse, homogeneous, pink Diffuse, homogeneous, pink hyalinehyaline thickening of the thickening of the
walls of arterioles.walls of arterioles.
Loss of underlying structural detail and narrowing of the Loss of underlying structural detail and narrowing of the
lumenlumen
Occurs typically in Occurs typically in elderlyelderly patients. patients.
Advanced lesions are seen in persons with diabetes Advanced lesions are seen in persons with diabetes
mellitus and/or with hypertension.mellitus and/or with hypertension.
14. HyalineHyaline ArteriolosclerosisArteriolosclerosis
Hyaline arteriolosclerosis is typically seen in Hyaline arteriolosclerosis is typically seen in kidneyskidneys. .
Endothelial injury causes leakage of plasma components Endothelial injury causes leakage of plasma components
across vascular endothelium, and excessive extracellular across vascular endothelium, and excessive extracellular
matrix production by smooth muscle cells.matrix production by smooth muscle cells.
This process is associated with luminal narrowing that This process is associated with luminal narrowing that
may induce ischemic injurymay induce ischemic injury
Afferent & efferent arterioles in kidney Afferent & efferent arterioles in kidney → → benign benign
nephrosclerosisnephrosclerosis
17. HyperplasticHyperplastic ArteriolosclerosisArteriolosclerosis
Concentric laminated (Concentric laminated (onion skinonion skin) arteriolar thickening with) arteriolar thickening with
reduplicated basement membrane and smooth musclereduplicated basement membrane and smooth muscle
cells proliferation.cells proliferation.
Commonly associated withCommonly associated with malignant hypertensionmalignant hypertension
Leads to luminal narrowingLeads to luminal narrowing
Frequently associated with fibrinoid necrosisFrequently associated with fibrinoid necrosis
((necrotizing arteriolitisnecrotizing arteriolitis).).
Later, the vascular wallsLater, the vascular walls hypertrophyhypertrophy due todue to
hyperplasia of SMCs and sometimes this occurs alonghyperplasia of SMCs and sometimes this occurs along
with necrosis of the vessel wall.with necrosis of the vessel wall.
21. Hypertensive heart disease (HHD)Hypertensive heart disease (HHD)
Basics for diagnosisBasics for diagnosis
History of hypertensionHistory of hypertension
Left ventricular hypertrophyLeft ventricular hypertrophy in the absence of otherin the absence of other
causes accounting for hypertrophycauses accounting for hypertrophy
The stimulus for hypertrophy is pressure overloadThe stimulus for hypertrophy is pressure overload
22. Hypertensive heart disease (HHD)Hypertensive heart disease (HHD)
Stages of HHDStages of HHD
CompensatedCompensated HHD:HHD:
With hypertrophy an adequate cardiac output isWith hypertrophy an adequate cardiac output is
maintained.maintained.
DecompensatedDecompensated HHD:HHD:
Thickness of muscle wall increase demand forThickness of muscle wall increase demand for
oxygen, decrease compliance, and role ofoxygen, decrease compliance, and role of
hypertension on atheroma, all contribute tohypertension on atheroma, all contribute to
decompensated HHD and eventual dilatation.decompensated HHD and eventual dilatation.
23. Hypertensive heart disease (HHD)Hypertensive heart disease (HHD)
GrossGross
Compensated stage .....Compensated stage ..... ConcentricConcentric hypertrophyhypertrophy
Decompensated stage .........Decompensated stage ......... DilatationDilatation
Both stages, heart weight increasedBoth stages, heart weight increased
Histology: Large fibers with large nuclei, laterHistology: Large fibers with large nuclei, later interstitialinterstitial
fibrosis.fibrosis.
HHD Causes deathHHD Causes death
CHFCHF
Increased risk of sudden cardiac deathIncreased risk of sudden cardiac death
Renal disease , strokeRenal disease , stroke
Drug control leads to regression of hypertrophy.Drug control leads to regression of hypertrophy.
24. Cor pulmonaleCor pulmonale
Cor pulmonale consists ofCor pulmonale consists of right ventricular hypertrophyright ventricular hypertrophy
and dilation due to pulmonary hypertension caused byand dilation due to pulmonary hypertension caused by
primary disorders of the lung parenchyma or pulmonaryprimary disorders of the lung parenchyma or pulmonary
vasculature.vasculature.
Generally, right ventricular dilation and hypertrophyGenerally, right ventricular dilation and hypertrophy
caused by congenital heart disease or by left ventricularcaused by congenital heart disease or by left ventricular
failure are excluded by this definition.failure are excluded by this definition.
25. Cor pulmonaleCor pulmonale
Cor pulmonale may be acute or chronic.Cor pulmonale may be acute or chronic.
Acute cor pulmonaleAcute cor pulmonale most commonly follows massivemost commonly follows massive
pulmonary embolism with obstruction of >50% of thepulmonary embolism with obstruction of >50% of the
pulmonary vascular bed.pulmonary vascular bed.
Chronic cor pulmonaleChronic cor pulmonale occurs secondary to prolongedoccurs secondary to prolonged
pressure overload caused by obstruction of thepressure overload caused by obstruction of the
pulmonary vasculature, or compression or obliterationpulmonary vasculature, or compression or obliteration
of septal capillaries (resulting from emphysema,of septal capillaries (resulting from emphysema,
interstitial pulmonary fibrosis, or primary pulmonaryinterstitial pulmonary fibrosis, or primary pulmonary
hypertension).hypertension).
26. Cor pulmonaleCor pulmonale
In acute cor pulmonale the right ventricle is usually dilatedIn acute cor pulmonale the right ventricle is usually dilated
but does not show hypertrophy; if an embolism causesbut does not show hypertrophy; if an embolism causes
sudden death the heart may even be of normal size.sudden death the heart may even be of normal size.
Chronic cor pulmonale is characterized by right ventricularChronic cor pulmonale is characterized by right ventricular
(and often right atrial) hypertrophy. In extreme cases the(and often right atrial) hypertrophy. In extreme cases the
thickness of the right ventricular wall may be comparablethickness of the right ventricular wall may be comparable
to or even exceed that of the left ventricle.to or even exceed that of the left ventricle.
When ventricular failure develops the right ventricle andWhen ventricular failure develops the right ventricle and
atrium may also be dilated. Such dilation may mask rightatrium may also be dilated. Such dilation may mask right
ventricular hypertrophy.ventricular hypertrophy.
