Manifestation of Novel Social Challenges of the
European Union
in the Teaching Material of
Medical Biotechnology Master’s Programmes
at the University of Pécs and at the University
of Debrecen
Identification number: TÁMOP-4.1.2-08/1/A-2009-0011
Manifestation of Novel Social Challenges of the
European Union
in the Teaching Material of
Medical Biotechnology Master’s Programmes
at the University of Pécs and at the University
of Debrecen
Identification number: TÁMOP-4.1.2-08/1/A-2009-0011
Miklós Székely and Márta Balaskó
Molecular and Clinical Basics of Gerontology – Lecture
8
CHARACTERISTICS OF
THE CARDIOVASCULAR
SYSTEM,
ABNORMALITIES AND
DISEASES PART 1
TÁMOP-4.1.2-08/1/A-2009-0011
Mortality data
In 1995 the leading causes of
death were:
1 Cardiovascular 50.7%
2 Malignancies 22.9%
3 Diseases of the GI tract 8.1%
4 Injuries, poisons, violence 7.8%
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Prevalence
Leading cause of death in both
gender was cardiovascular (even
preceding malignancies)
• 65-74 years 50-52%
• above 75 years 60%
Age-related physiological
changes
in the heart 1
TÁMOP-4.1.2-08/1/A-2009-0011
• Each ventricle pumps 200,000 m3 blood
in 60 years through 40,000 km long
capillary system with 1,000 m2 surface
• The aging of the cardiovascular system
determines survival and longevity
(100-120 years).
Age-related physiological
changes
in the heart 2
TÁMOP-4.1.2-08/1/A-2009-0011
Autonomic
modulation
Growth
factors
(AII, NE,
ET, TGFβ)
Cardiac
factors:
Contractilit
y Stretch
(systolic,
diastolic)
Vascular
factors:
Pulsatile
elastance
reflected
waves
Nonpulsatile
PVR
Autonomic
modulation
Age-related physiological
changes
in the heart 3
TÁMOP-4.1.2-08/1/A-2009-0011
• In normotensive individuals a moderate,
age-related thickening of the ventricular
wall may be physiological
• The size of the left atrium and the
internal diameter of ventricle also
increases with age (not always
statistically significant)
• On a chest X-ray an increase of heart
contours is observed
• Hypertrophy of the myocytes is mostly
behind the thickening of the ventricular
wall, but increase in the connective
Age-related physiological
changes
in the heart 4
TÁMOP-4.1.2-08/1/A-2009-0011
• Early diastolic filling of the heart
decreases (at the age of 80 years ca.
50%, in the young 2× as much blood
flows into the ventricle than in later
phases)
• The mitral valve closes more slowly
• The late diastolic filling is
quicker/more effective (due to the
contraction of the heart) (filling in
the elderly early:late=1:1)
• EDV mostly increases particularly in
Age-related physiological
changes
in the heart 5
TÁMOP-4.1.2-08/1/A-2009-0011
At rest
During
Exercise
Young
heart
At the start
of
heart beat, at
rest
At the end of
heart beat, at
rest
Size at the start of Size at the end of
heart beat
heart beat
is the same as at rest is smaller than at
rest
At the start
of
heart beat, at
rest
At the end of
heart beat, at
rest
Size at the start of Size at the end of
heart beat
heart beat
is larger than at rest is the same as at
rest
Old
heart
Age-related physiological
changes
in the heart 6
TÁMOP-4.1.2-08/1/A-2009-0011
• The number of the atrial pace-maker
cells decreases 50-75% by the age of
50 – pulse decreases
• The cell count of the AV node is
maintained, but the speed of
conduction is slower
• His cell count decreases – fibrosis
• The heart rate at rest remains normal,
but exercise induced maximum decreases
by 30% (by the age of 80) the maximal
possible heart rate and cardiac output
Cardiac output measured at rest
and at exhausting exercise
(upright position) vs. age in
athletes and sedentary individuals
Cardiac output (L/min)
TÁMOP-4.1.2-08/1/A-2009-0011
20
D
16
12
C
8
B
4
A
20
40
60
Age (years)
80
Age-related physiological
changes
in the circulation 1
TÁMOP-4.1.2-08/1/A-2009-0011
• The arterial wall becomes more rigid,
the aorta shows distension: due to the
quantitative and qualitative changes
in elastin and collagen fibers.
• Calcium deposition and collagen crosslinks make the vessels even more
rigid.
• Glycoprotein disappears from the
elastic fibers, they become
fragile/brittle, the mineral content
of the elastin increases, the polar
amino acid content also rises.
Age-related physiological
changes
in the circulation 2
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• Remodelling of the small vessels, the
functional capillary number decreases – the
oxygen supply of the tissues decreases!
• The thickness of the tunica intima and media
increases, e.g. in the a. carotis communis
the normal mean of 0.35 mm – may increase to
2-3-times higher (higher levels of growth
factors, smooth muscle proliferation,
transformation)
• The tone of the vessels changes
NO decreases, ROS, TxA2 PGH2 increase
Ca-dependent vasoconstriction is
Ca-activated or voltage-dependent K+-channel
a-subunit density decreases in the vascular
Age-related physiological
changes
in the coronary circulation
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• The myocardial contractility decreases
• The duration of both the systole, and
the diastole increases (slower)
(ionflux of the L type Ca++ channels
increases, their activity becomes
longer)
• Due to the fall of the diastolic
pressure the coronary circulation
decreases
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Changes in the
cardiovascular function 1
Ventricular filling, preload
• The early filling becomes
progressively slower after the age of
20, by 80-y it is only half of the
original
• despite this, the EDV does not
decrease in healthy old people,
because the major part of the filling
takes place in the second phase
• The enlargement of the atria and their
stronger contraction is responsible
Comparison between the
early diastolic and atrial contribution
to
left ventricular filling in persons of a
broad age range
women
40
80
30
70
20
60
0
men
50
90
50
Late diastolic filling due to atrial
contraction
(% of total filling volume)
Early diastolic filling volume
(% of total filling volume)
TÁMOP-4.1.2-08/1/A-2009-0011
20
40
60
80
Age (years)
100
10
0
20
40
60
80
Age (years)
100
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Changes in the
cardiovascular function 2
Ventricular filling , preload
• In auscultation 4th (atrial)
sound appears – gallop rhythm
• In acute atrial fibrillation the
loss of coordinated atrial
contraction leads to a loss of
this function. In people with
chronic left ventricular failure
it leads to an acute heart
failure
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Changes in the
cardiovascular function 3
Afterload
• the vessels are more rigid
• the speed of the pulse wave is up – with a
quick reflection of the pulse wave, already
within the systole, interference of waves may
decrease the coronary circulation
• the sensitivity of the baroreceptor reflex
decreases
• the systolic blood pressure increases
• the ventricular emptying is impaired
• dilatation of the left ventricle
• the thickening of the ventricular wall may
have benefits according to the LaPlace law),
normalizing the systolic function and the
TÁMOP-4.1.2-08/1/A-2009-0011
Myocardial contractility
The myocardial performance, i.e.
the cardiac output depends
(besides the pre- and afterload)
on the contractility of the heart
The interplay of vascular and
adaptive cardiac changes during
aging
TÁMOP-4.1.2-08/1/A-2009-0011
 aortic prolonged
root size contracti
on
 pulse
wave
velocit
arteria
y
l
and
stiffen
early
ing
reflect
ed
waves

systoli
c
blood
pressur
e with
late
peak
 early
diastolic
filling
normal
Normali LV
 LV
endsation of
systolic
wall
hyperLV wall
volume and
tension trophy
tension
ejection
fraction
Normal
 atrial  atrial
endsize
filling
diastolic
and
volume
contracti
on