A
Aortic
Pressure
Mm Hg
Ventricular
Pressure
The P wave denotes
atrial depolarization.
Ventricular
Volume
0
130
ml
P
EKG
120
40
B
Aortic
Pressure
Contracting atria
cause ventricular
volume and pressure
to increase – See units
to the right
Ventricular
Pressure
Ventricular
Volume
Mm Hg
0
130
ml
P
EKG
120
PR interval of EKG
Atria depolarized and
contracting
40
C
Aortic
Pressure
Mm Hg
Ventricular
Pressure
Preload – Usually
represented as the
pressure immediately
preceding ventricular
contraction
Ventricular
Volume
0
130
ml
P
EKG
120
40
Following ventricular
depolarization the
120
ventricles begin to contract
this causes the pressure
in the ventricles to begin to Mm Hg
rise and the AV valves
close. However, since all
the valves are now shut……0
Aortic
Pressure
Ventricular
Pressure
ventricular volume
remains constant as
no blood can leav
(isovolumetric)
Ventricular
Volume
P
EKG
QRS represents
depolarization of
the ventricles
D
130
ml
40
E
AV valves close
Aortic
Pressure
Ventricular
Pressure
Ventricular
Volume
P QRS
EKG
To review, the QRS
wave denotes
ventricular
depolarization. This
is followed by
ventricular contraction
causing pressure in
the ventricles to begin
to rise. This
intraventricular
pressure increase
immediately closes
the AV valves.
120
Mm Hg
0
130
ml
40
AV valves close
Aortic
Pressure
Semilunar valves open
Ventricular
Pressure
Ventricular
Volume
F
P QRS
EKG
As pressure builds in
the ventricles all the
valves remain shut.
Aortic and pulmonary
artery pressures
oppose opening of the
respective valves.
They remain closed
until ventricular
pressures very slightly
exceed the arterial
pressures in these
vessels. When this
pressure is achieved,
the pulmonary and
aortic valves open.
120
Mm Hg
0
130
ml
40
AV valves close
120
Aortic
Pressure
Semilunar valves open
Ventricular
Pressure
Ventricular
Volume
Mm Hg
0
130
ml
P QRS
EKG
As long as ventricular
pressure exceeds
arterial pressure, blood
is squeezed out of the
ventricles and their
volume decreases.
40
G
H
AV valves close
Aortic
Pressure
Semilunar valves open
Ventricular
Pressure
Afterload
Preload
120
Mm Hg
0
Afterload is the
intraventricular
130
pressure required
to cause blood to
ml
exit the ventricles.
It varies
throughout the
40
ejection phase.
Ventricular
Volume
P QRS
EKG
F,
AV valves close
I
Aortic
Pressure
Semilunar valves open
Ventricular
Pressure
Afterload
120
Mm Hg
Note that aortic 0
pressure is lower
than ventricular 130
pressure while
blood is exiting
ml
the ventricle
Ventricular
Volume
40
P QRS
EKG
F,
AV valves close
Aortic
Pressure
Semilunar valves open
Ventricular
Pressure
Semilunar valves close
Ventricular
Volume
J
P QRS
EKG
F,
120
After a period of
time the
ventricles cease
to contract and Mm Hg
begin relaxing.
When this
0
occurs, the
pressure in the
130
ventricles drops
below arterial
pressure and the ml
aortic and
pulmonary valves 40
are pushed shut
by backflow of
blood into their
chambers.
AV valves close
120
Aortic
Pressure
Ventricular
Pressure
Semilunar valves close
Ventricular
Volume
K
P QRS
EKG
T
F,
J,
Relaxation
Mm Hg
begins after
the T wave of
0
the EKG. With
the aortic
130
valve shut,
ventricular
pressure drops ml
but volume
stays constant
40
(isovolemic)
because all
the valves are
closed.
AV valves close
120
Aortic
Pressure
When
ventricular
pressure is Mm Hg
less than
atrial
0
pressure the
AV valves
130
open and
blood enters
the ventricles ml
which
increases
40
their volume.
Semilunar valves open
Ventricular
Pressure
Semilunar valves close
Ventricular
Volume
L
P QRS
EKG
T
F,
J,
AV valves close
120
Aortic
Pressure
Please take
note on this Mm Hg
panel when
the valves
0
open and
close and
130
what events
are
ml
associated
with their
opening and 40
closing.
Semilunar valves open
Ventricular
Pressure
Semilunar valves close
Ventricular
Volume
AV valves open
M
P QRS
EKG
T
F,
J,
Systole
AV valves close
120
Aortic
Pressure
Ventricular
systole is that Mm Hg
time when the
ventricles are
0
contracting
and includes
130
the
isovolumetric
contraction
ml
and ejection
phases.
40
Semilunar valves open
Ventricular
Pressure
Semilunar valves close
Ventricular
Volume
AV valves open
N
P QRS
EKG
T
F,
J,
Diastole
AV valves close
Aortic
Pressure
Ventricular
Mm Hg
diastole is
that time
0
when the
ventricles
are relaxed. 130
Semilunar valves open
Ventricular
Pressure
Semilunar valves close
Ventricular
Volume
ml
AV valves open
O
40
P QRS
EKG
120
T
F,
J,
AV valves close
AV valves open
Aortic
Pressure
Semilunar valves close
Left Ventricular
and aortic
pressure
profiles.
Semilunar valves open
120
Left
Ventricular
Pressure
Mm Hg
0
AV valves close
AV valves open
Aortic
Pressure
Semilunar valves close
Right
Ventricular
Pressure
Semilunar valves open
120
Left
Ventricular
Pressure
Pulmonary
Artery
Pressure
Right ventricular and pulmonary artery
pressure profiles.
Mm Hg
0
120
Mm Hg
“c” wave (ventricular contraction)
“a” wave
atrial contraction
“v” wave (ventricular
filling)
0
Jugular Venous Pressure