2. Introduction to Electrocardiogram
• It is sometimes referred to as an ECG or an EKG
• In the late 1880’s, it was discovered that the electrical
activity of the heart could be monitored through the skin
• In 1901, Dutch physiologist Willem Einthoven invented
the electrocardiograph machine, to record the heart’s
electrical activity. He identified and named the
waveforms produced by the heart’s electrical system
– P, Q, R, S, and T
3. Introduction
• An electrocardiogram or ECG (EKG)
– Is a graphic recording of the electrical activity of
the heart.
– Converts the heart’s electrical activity into lines
called “Waveforms”
• Can be seen on a monitor or printed out on paper
4. Introduction
• Today, ECG monitoring is used in a variety of
settings. It is an important tool that provides vital
information including:
– Heart rate
• How fast the heart is beating
– Heart rhythm
• Whether the rhythm of the heartbeat is steady or irregular
– Conduction abnormalities
• The strength, timing, and conduction of electrical signals as
they pass through each part of the heart
5. ECG Indications
• The ECG is used to detect and evaluate many
heart problems such as:
– Abnormal heart rhythms
• Arrhythmias
– Heart failure
• A condition in which the heart can’t pump blood the
way it should
– Heart attacks
• Known as an MI or myocardial infarction
6. ECG Indications
• The ECG is also used to continually monitor
how a patient’s heart is working while they
are in the hospital if they have a heart related
illness or a history of heart disease
7. ECG Indications
• In some cases, patients may have ECG
monitoring even though their main illness is
not heart-related.
– Some medical disorders and procedures can affect
heart function
8. ECG Indications
• Indications for cardiac monitoring include:
– Myocardial infarction or ischemia
– Surgical procedures
– Fluid and electrolyte imbalances
– Hemorrhage
– Drug toxicities
– Cardiac history
– Trauma
– Respiratory illnesses
– Kidney failure
– Infections
13. ECG Equipment
• EKG machine equipment includes the ECG
machine, electrodes, paper, and connecting wires
• In order to pick up the electrical activity of the
heart, at least three electrodes are placed on the
patient’s body and connected to the ECG monitor
by the connecting wires
– 1 positive, 1 negative, and 1 ground
• When electrical activity occurs in the
heart, waveforms are seen on the ECG
15. ECG Equipment
• Electrodes
– Are applied at specific locations on the patient’s
chest wall and extremities to view the heart’s
electrical activity from different angles and planes
16. Electrodes
• How to apply
– Always explain procedure
– Expose and privacy
– Choosing a site
– Gel
– Applying new electrodes
19. Lead System
• In order to pick up the electrical activity of the heart, at
least three electrodes are placed on the patient’s body
and connected to the ECG monitor by cables
– One positive, one negative, and one ground
• A lead refers to the position of the positive and
negative electrodes as programmed by the ECG
monitor.
• Different leads are used to view the electrical activity
at different parts of the heart
• Monitoring systems may have three to six electrodes,
which allow for monitoring in several leads
simultaneously
21. Lead System
• Right Side
– ER
– Nurse
– Reverse V3, V4, V5, and V6 to the right side of the
chest instead of left side of chest
• V1 and V2 stay in original position
– Mark “right side” on the ECG print out
22. ECG Paper and Measurements
• ECG paper
– is a graph paper used to measure rates of impulse
formation and the duration of the electrical events
that occur in the heart
– Made up of vertical and horizontal lines, which
form large and small boxes
23. ECG Paper and Measurements
• Vertical lines
– Measure voltage (measured in millivolts)
• Horizontal lines
– Each small box equals 0.04 seconds of time and
each large box equals 0.20 seconds of time
24. ECG Paper and Measurements
• Some ECG graph paper has markings above or
below the graph to mark seconds of time. In
the example below, there are markings for
every 1 second of time
25. ECG Paper and Measurements
• Printing
– How to?
– Entering data
– Recording information
26. Machine Maintenance
• Always plug machine into red electrical outlet
when not in use
• Check machine for supplies daily
– paper, electrodes, alcohol prep pads, germicidal
wipes
• Check all lead wires for breaks
• Check electrode clips for intactness
27. Monitor Problems
• How do you know your limb leads have been
placed on the patient correctly?
– Artifact
– Interference
– Wandering baseline
– Faulty equipment
• Corrective Actions
