CG
As cardiac impulse passes through the heart, electrical currents speads into the tissue surrounding the heart and a small
proportion spreads all the way to the surface of the body. Our body is made of 70% water and water is a good conductor of
electricity.
Electrical activity of the heart is picked upon on the skin via electrodes, with an ECG displaying it graphically illustrated how
depolarisation wave moves through the heart.
ECG measures the
difference in charge
aiross myo la dial cells
as the wave of
depolarisation moves
through the heart
At rest
sation calls be ome y
cells are A
charged relative charged compared
with outside
to outside environment
environment
WMWM A dipole vector pointing
towards positive
a
eleitrode shows ECG
tracing with positive
deflection Tracing is
displayed gap
12 leads of ECG represent 12 electrical views of the heart from
12 different angles
Conventional ECG has 11 leads involving attainment of 10 electrodes
to the body
4 one in each limb
6 across the chest team
These give you
12,19 lead 11
li 7 auf aVR all
6 chest leads
, 6 limbs leads
Look at the heart in a vertical plane obtained from 3 eleitrodes
measurement of voltage requires
two terminals 0 and
LEAD I to
zero reference
Point of view
finthover's
triangle ego f
in connecting
y
line of sight
zero LEAD Ill
LEAD
RL elentrode
earth
eleitrode É
Bipolar leads lead I right arm left arm
elentrical
measure
potential 2 out of Lead 11 right arm left leg
3 limb ele it odes
Lead ill let arm left leg
f A
Augmented limb leads
AVL AUF AUR unipolar leads
aur look at alk look electrode
limb
upper rt side at upper it they use one
as t terminal and take the
of heart side of
Q heart average of inputs from the
g other two a zero ref E
I I
I
I 10
1
I
zergeference
i
AUF F foot
inferior wall of
the heart
As cardiac impulse passes through the heart, electrical currents speads into the tissue surrounding the heart and a small
proportion spreads all the way to the surface of the body. Our body is made of 70% water and water is a good conductor of
electricity.
Electrical activity of the heart is picked upon on the skin via electrodes, with an ECG displaying it graphically illustrated how
depolarisation wave moves through the heart.
ECG measures the
difference in charge
aiross myo la dial cells
as the wave of
depolarisation moves
through the heart
At rest
sation calls be ome y
cells are A
charged relative charged compared
with outside
to outside environment
environment
WMWM A dipole vector pointing
towards positive
a
eleitrode shows ECG
tracing with positive
deflection Tracing is
displayed gap
12 leads of ECG represent 12 electrical views of the heart from
12 different angles
Conventional ECG has 11 leads involving attainment of 10 electrodes
to the body
4 one in each limb
6 across the chest team
These give you
12,19 lead 11
li 7 auf aVR all
6 chest leads
, 6 limbs leads
Look at the heart in a vertical plane obtained from 3 eleitrodes
measurement of voltage requires
two terminals 0 and
LEAD I to
zero reference
Point of view
finthover's
triangle ego f
in connecting
y
line of sight
zero LEAD Ill
LEAD
RL elentrode
earth
eleitrode É
Bipolar leads lead I right arm left arm
elentrical
measure
potential 2 out of Lead 11 right arm left leg
3 limb ele it odes
Lead ill let arm left leg
f A
Augmented limb leads
AVL AUF AUR unipolar leads
aur look at alk look electrode
limb
upper rt side at upper it they use one
as t terminal and take the
of heart side of
Q heart average of inputs from the
g other two a zero ref E
I I
I
I 10
1
I
zergeference
i
AUF F foot
inferior wall of
the heart
