2. Contents
• Introduction
• History
• What are the different ways to measure ECG
• Principle of electrocardiogram
• Application of ECG
• Purpose of ECG
• Operation
• ECG interpretation
4. Introduction
• An electrocardiogram or ECG records the
electrical activity of the heart .The heart
produces tiny electrical impulses which spread
through the heart muscle to make the heart
contract
• These impulses can be detected by the ECG
machine
• The ECG test is painless and harmless
5. History
• William Einthoven (a Dutch physiologist )made
the first ECG recording in 1895
• P,Q,R,S,T waves are also first defined by
Einthoven in 1895
• In 1995 William Einthoven recorded ECG in his
laboratory which was located 1.5km away
from the hospital
• The patient was in the hospital while his ECG
was being recorded in the laboratory 1.5km
away
6. History
• William Einthoven first published his normal
and abnormal ECG recording in 1906
• In 1924 William Einthoven received noble
prize for his invention of ECG
7. What are the different ways for
measuring ECG
Telectrocardiogram • The first ECG machines
were very large and bulky,
weighing around 275 Kgs
(600 lbs). It was not possible
to bring these machines to
the patient's bedside.
• Doctors had to connect the
electrodes to the patient
and the information would
be transmitted (telemetry)
to the ECG machine in
another room with the help
of connecting cables.
8. continued
Wireless ECG • This is a modern day
innovation of the traditional
clinical ECG machine with
similar functional capabilities.
Electrodes do not have wirers
directly attached to the
recording or monitoring
machine. These electrodes can
transmit the signal wirelessly
over to the receiver in the ECG
machine.
• Wireless ECG machine can
offer more flexibility for the
patients. This is especially
useful when combined with a
treadmill test where the lack
of cables can offer more
freedom of movement during
the test.
9. continued
• 12 lead ECG test • This is the modern
adaptation of the original
Willem Einthoven ECG
machine based on the
Einthoven’s Triangle
principles. It is the standard
ECG machine used in clinical
settings today. In 1942
Emanuel Goldberger added
3 more leads know as
augmented limb leads (aVR,
aVL and aVF) to Willem
Einthoven's limb leads (I, II
& III) and six chest leads
(V1, V2, V3, V4, V5 & V6)
forming the basis of the 12
lead ECG.
10. continued
• 5 lead ECG monitoring
• Occasionally a 5 lead ECG
is also used for
monitoring purposes. It
uses 4 electrodes like a 3
lead ECG with an
additional 5th electrode
placed on the chest.
Usually these devices do
not produce a print out of
the electrocardiogram
and may not store the
information for further
review.
• 3 and 5 lead variations of
ECG monitoring does not
provide detailed views
like a 12 lead ECG, but is
most often sufficient for
monitoring purposes. A
12 lead ECG is the
standard equipment of
choice for diagnosing
heart disease in a clinical
situation.
11. continued
• Holter’s monitor
• Holter Monitor is a
portable ECG monitor
that can be worn by a
patient for duration of 24
to 48 hours while the
device continuously
monitors the heart
rhythm. It has fewer leads
than a normal clinical ECG
machine. The patient is
free to move around and
go around their usual
daily routines.
12. continued
• Cardiac event recorder • Sometimes the symptoms may
not appear during the ECG and
a Holter Monitor test. In such
cases, the doctor may suggest
a Cardiac Event Recorder than
can be worn continuously for
an extended period of time (2-
4 weeks). The device is the size
of a deck of cards and cables
to the recording device
connect the electrodes. Unlike
the Holter Monitor, an Event
recorder does not
continuously record the heart
rhythm.
13. continued
• Cardiac loop recorder • A loop recorder is a
compact USB pen drive
sized medical device to
monitor the heart function.
It can be attached to the
surface of the skin around
the area of the patient's
heart. It continuously
records the heart rhythm
for a certain duration,
depending on the memory
capacity of the device and
when the device memory is
full, it starts overwriting
from the beginning of the
recording. Hence the name,
loop recorder
14. continued
• Implantable loop
recorder
• ILR is a miniature loop
recorder that can be
implanted between the
chest skin and the rib
cage, above the heart.
Like the loop recorder it
can be programmed to
automatically start
recording when an
abnormality is detected
is detected in the heart
rhythm
15. continued
• Stress ECG • Stress ECG is also
known as Cardiac stress
test or treadmill test. In
patients that can walk,
the test is conducted on
a treadmill. The patient
is connected to an ECG
monitoring machine
and is asked to start
walking on the treadmill
16. Principle of electrocardiogram
• Electrocardiogram is an electrical activity of the
heart
• The basic principle of ECG is that stimulation of a
muscle alters the electrical potential of the
muscle fibres
• Cardiac cells unlike others cells have a property
known as automacity which is the capacity to
spontaneously initiate impulses.
• These are then transmitted from cell to cell by
gap junctions that connect cardiac cells to each
other
17. continued
• The electrical impulses spread through the muscle
cells because of change in ions between
intracellular and extracellular fluid.
• The primary ions involved are calcium, sodium and
potassium
• The action potential is the potential for action
created by the balance between electrical charges
of ions on either side of the cell membrane
18. Bio-electric signal
• Polarization:potassium ion pumped in and
sodium ions pumped out
• Depolarization: potassium ion pumped out
and sodium ions pumped in
• Repolarization:potassium ion pumped in and
sodium ions pumped out
20. Purpose of ECG
• Heart rate
• Heart rhythm
• Analysis of”conduction abnormalities”
• Whether there has been a prior heart attack
• Whether there may be coronary artery
disease
• Whether the heart muscle has become
thickened
21. Applications of ECG machine
• Casuality
• Intensive care unit
• Intensive cardiac care unit
• Wards
• Cardiac department
• General practitioners
22. Operation
• Preparation of patient
• Placement of electrodes
• Bipolar leads (I,II,III)
• Unipolar lead(avR ,avL ,avF)
• Pre-cordial leads(v1 to v6)
23. Preparing the patient
• The patient or the person whose ECG is to be taken
should be in supine position.
• Patients limbs,legs,chest should be exposed to fix
ECG electrodes.
• Clean the portion where the electrode has to be
attached. If patient chest is hairy , shave the portion
and clean the area by alcohol swab or spirit.
• The skin or area where electrodes to be placed
should be dry and clean
24. Placement of electrodes
• Apply gel on he body surface
• Place the limb electrodes to hand(near the
wrist)and legs (near the ankle)
• The electrodes need to be in proper contact with
the skin at all time to maintain a good reading
through out the ECG monitoring process
• The patient is now ready for the electrode
placement , apply the electrodes and if needed
add ECG conductive gel to the electrodes
27. continued
• Recorded on graph paper
• Time is measured across horizontal axis
• Voltage or amplitude is measured up and
down
• Small squares=1mm high,0.04 seconds wide
• 5 small square=1 large square
• 1 large square is 5mm high and 0.20 sec wide
28. About 6208 view
• Cardiart 6208 view plus is a 3 channel
electrocardiograph with 12 leads gathered
simultaneously,visual display of operation
menu,Ecg parameters as well as
electrocardiogram
• 3 channel ECG can be viewed on the LCD screen
• It can be recorded by high quality thermal
printer
29. continued
• Auto,manual,rhythm,USB print and off mode
can be chosen conveniently
• Either mains supply or built in rechargeable
lithium battery can be used as power
• Low weight and compact size
• Touch key for easy operation
• High resolution thermal printer
30. Safety precautions
• Avoid moisture or contact with water
excessive humidity and temperature
• The ECG machine should be kept in clean and
dry place whenever not in use
• Keep away the ECG machine from any x-ray,
ultrasonic or other electronic instruments
• Use only 3 prong power cord provided with
ECG machine
• Clean all accessories and reusable electrodes,
wipe out extra jelly and clean patient cable
properly
31. continued
• The ECG machine which to be tested should be
dry and clean
• Check the patient lead wires and cables for any
damage or mishandling, otherwise replace the
same immediately
• Recommend using proper size and placement
of recording paper
• Clean the print head regularly for clear print out
• The ECG machine battery should be kept
charging before and after use
32. continued
• Check the battery status regularly
• The prolonged storage under high
temperature ,direct sunlight and fluorescent
light and excessive humidity may cause the
fading of recording result, which may
deteriorate the print head of recorder
• Store the recording paper in cool, dry and dark
place
33. Troubleshooting
• Physical conditions: panel, keypad, chassis,
controls, cables
• Cleanliness: are chassis clean
• Accessories: are leads ,extension cables,gel
pads,recording paper,chest electrodes present
• Power up:no abnormal heat,smell,smoke
shouldn’t be there
• Indicator’s :is AC main’s battery lit
• Display :is display well lit
34. Troubleshooting
• Controls: is all keys/controls operating
properly
• Battery: is battery fully charged
• Recorder: is paper feed working
• Is waveform printout is clear and satisfactory
• Is date and time printed correctly
35. Clean,care,maintenance
• Clean the main unit and patient cable
• Clean the electrodes
• Clean the print head
• Charge the battery
• Store in good place while not in use
