Assoc. Prof. MUDr. Markéta Bébarová, Ph.D.
Arterial Hypertension
Dept. of Physiology, Faculty of Medicine, Masaryk University
This presentation includes only the most
important terms and facts. Its content by
itself is not a sufficient source of
information required to pass the
Physiology exam.
Definition and Consequences
Arterial hypertension - chronic increase of the systemic
blood pressure.
Symptoms indistinctive and nonspecific in the first stages of
hypertension  almost 50% of the hypertensive patients do not
know about their hypertension!
 overload of the left ventricle (hypertrophy, heart failure)
 arteriosclerosis
increased risk of the myocardial infarction
increased risk of the stroke
the renal failure, etc.
If not diagnosed in time and adequately treated, arterial
hypertension results in:
Hypertension significantly shortens the life span.
Definition and Consequences
Arterial hypertension - chronic increase of the systemic
blood pressure.
Guidelines for the management of arterial hypertension. Eur Heart J 2007;28:1462-1536.
Methods of blood pressure measurement
Proper way of blood pressure measurement
Definition and Consequences
Arterial hypertension - chronic increase of the systemic
blood pressure.
Guidelines for the management of arterial hypertension. Eur Heart J 2007;28:1462-1536.
prehypertension
Definition and Consequences
Arterial hypertension - chronic increase of the systemic
blood pressure.
Guidelines for the management of arterial hypertension. Eur Heart J 2007;28:1462-1536.
Definition and Consequences
Guidelines for the management of arterial hypertension. Eur Heart J 2007;28:1462-1536.
Stratification of cardiovascular risk
Definition and Consequences
in children and adolescents – special percentile tables
Guyton and Hall.
Textbook of Medical Physiology, 11th edition
Factors Determining Blood Pressure
Ohm´s law
U = I . R P = CO . TPR
 cardiac output
volume-loading (hyperdynamic, volume
dependent) h.
↑ ↑
 total peripheral resistance
resistance (non-volume dependent) h.
↑
Guyton and Hall.
Textbook of Medical Physiology, 11th edition
Factors Determining Blood Pressure
Ohm´s law
U = I . R P = CO . TPR
 compliance isolated systolic hypertension
↑
 cardiac output
volume-loading (hyperdynamic, volume
dependent) h.
↑ ↑
 total peripheral resistance
resistance (non-volume dependent) h.
↑
veins
blood reservoire
heart
CO = SV . HR
HR is guided by
sympathetic and
parasympathetic
system
SV depends on:
1.venous return
(blood volume,
tonus of veins)
2.contractility
3.peripheral
pressure
kidneys
regulation of
blood volume
P = CO . TPR
kidneys
regulation of
blood volume
P = CO . TPR
arterioles
regulation of
TPR
heart
CO = SV . HR
HR is guided by
sympathetic and
parasympathetic
system
SV depends on:
1.venous return
(blood volume,
tonus of veins)
2.contractility
3.peripheral
pressure
veins
blood reservoire
also TPR (RAS)
P = CO . TPR
arterioles
regulation of
TPR
veins
blood reservoire kidneys
regulation of
blood volume,
also TPR (RAS)
aorta and big
elastic arteries
compliance
heart
CO = SV . HR
HR is guided by
sympathetic and
parasympathetic
system
SV depends on:
1.venous return
(blood volume,
tonus of veins)
2.contractility
3.peripheral
pressure
P = CO . TPR
arterioles
regulation of
TPR
veins
blood reservoire
aorta and big
elastic arteries
compliance
regulation of
blood volume:
- kidneys
- thirst
- ADH
heart
CO = SV . HR
HR is guided by
sympathetic and
parasympathetic
system
SV depends on:
1.venous return
(blood volume,
tonus of veins)
2.contractility
3.peripheral
pressure
P = CO . TPR
arterioles
regulation of
TPR
veins
blood reservoire
aorta and big
elastic arteries
compliance
regulation of
blood volume:
- kidneys
- thirst
- ADH
heart
CO = SV . HR
HR is guided by
sympathetic and
parasympathetic
system
SV depends on:
1.venous return
(blood volume,
tonus of veins)
2.contractility
3.peripheral
pressure
Pathophysiology of hypertension is
very complex, thus, usually hard to be
analyzed in a concrete patient!
P = CO . TPR
Classification
A. Essential (primary) hypertension
B. Secondary (symptomatic) hypertension
• „hypertension of an unknown origin“
• 90 – 95%
A. Essential (primary) hypertension
• symptom of another primary disease with identifiable
cause
Essential Hypertension
 strong hereditary tendency in some patients
(polygenic ground)
 provoking factors:
• excess weight gain, obesity – account for about 65-70%
of the risk for developing of essential hypertension
• sedentary lifestyle
New clinical guidelines recommend increased physical
activity and weight loss as the first step in treating most
patients with the essential hypertension.
• excessive sodium intake (interpopulation studies –
Eskimos vs. people living in the North Japan)
• stress (namely mental)
Essential Hypertension
Sodium-loading renal function curves
Guyton and Hall.
Textbook of Medical Physiology, 11th edition
Definition and Consequences
Arterial hypertension - chronic increase of the systemic
blood pressure.
Guidelines for the management of arterial hypertension. Eur Heart J 2007;28:1462-1536.
Isolated Systolic Hypertension
Essential Hypertension
 in the elderly
 due to:
• age-dependent remodelling of the wall of elastic arteries
(less elastic and more collagen fibres)
 ↑ systolic and pulse pressure
 ↑ stiffness, ~↓ compliance:
2.  ↑ pulse wave velocity
1.  ↓ distension of elastic arteries during the systole
 steeply ↑ arterial systolic pressure + ↓ blood volume
(and also pressure) in arteries during the diastole
• endothelial dysfunction
Isolated Systolic Hypertension
Essential Hypertension
↑ pulse wave velocity  the secondary, reflected pulse wave
comes back to the aorta and elastic arteries sooner and, thus,
superimposes on the primary pulse wave still during the systolic
phase  ↑ systolic pressure and may even ↓ diastolic pressure
primary wave
reflected wave
resulting wave
Essential Hypertension
Treatment
New clinical guidelines recommend increased physical activity and
weight loss as the first step in treating most patients with EH.
 vasodilatory drugs
• ↓ TPR, some of them ↑ renal blood flow as well (ACEI)
a. by inhibiting sympathetic nervous system (sympatolytics)
b. by directly paralyzing the smooth muscle of the renal vasculature
(vasodilatory agents or calcium channel blockers)
c. by blocking action of the renin-angiotensin system on the renal blood
vessels or tubules (inhibitors of angiotensin I-converting enzyme, ACEI)
Decrease of sodium and increase of potassium intake, relaxation ...
 natriuretic (diuretic) drugs
• ↓ renal tubular reabsorption of salt and water  ↓ CO
(by blocking the active transport of sodium through the tubular wall)
P = CO . TPR
Classification
A. Essential (primary) hypertension
B. Secondary (symptomatic) hypertension
• „hypertension of an unknown origin“
• 90 – 95%
• symptom of another primary disease with identifiable
cause
Secondary Hypertension
3. Coarctation of the aorta
4. Hypertension in preeklampsia
5. Neurogenic hypertension
• Renin-producing renal tumor
1. Renal hypertension
• Acute and chronic diseases of the renal parenchyma
• Prerenal causes - Renovascular hypertension
• Postrenal causes (renal vein trombosis, urinary tract obstruction)
• Sympatoadrenal hyperfunction (pheochromocytoma)
2. Endocrine hypertension
• Adrenocortical hyperfunction (Cushing´s, Conn´s, adrenogenital sy)
• Exogenic hormones (gluko-, mineralocorticoids, sympatomimetics)
• Hyperthyroidism
• Acromegaly