3. Purposes
To assess the cardiac function (rate , rhythm and
conduction).
To diagnose cardiac rhythm disorders(e.g. heart
block, dysrhythmias )
To diagnose cardiac diseases (e.g. myocardial
infraction).
To detect the effects of electrolyte imbalance on
cardiac function(e.g. hyperkalemia, hypokalemia,
etc).
To evaluate effects of treatment (e.g. administration
of cardiac drugs).
5. Procedure:
Nursing action:
1.Explain the purpose of ECG and
procedure to the patient reassure
patient that procedure is painless and
safe.
Rationale
Helps to gain patient’s co-operation
and reduces anxiety regarding
procedure.
6. NURSING ACTION
2. ask female patient to remove all tight fitting
clothing around the chest. Assist patient to put on a
front open loose gown or shirt
RATIONAL:
Procedures requires placement of electrodes over
chest area.
7. 3.Ensure that the ECG machine is in functioning
order.
4. ensure proper standardization of machine
a. set paper speed at 25 mm/ minute
b. provide standard 1 mV signal to ECG machine
so that the spike made will be 10 mm or 2 large
squares in height.
c. ensure that the machine is properly earthed.
rationale
Proper standardization of machine ensures a precise
recording of ECG
8. 5.ask the patient to lie in supine position and be as
relaxed as possible.
If the patient needs to be transported to the ECG
department , transport him on a trolley. Never allow
him to walk till diagnosis is confirmed.
Rationale
Rigid posture and contraction of muscles may
result in artifacts on ECG record.
9. 6.provide privacy by pulling the curtains around the
patient.
rationale
Procedure requires exposing chest area , which is
embarrassing for patient.
10. 7.expose chest completely. Apply electrocunductive gel on
lead placement sites and position all electrodes
appropriately.
a. check for color codes of limbs and connect limb
electrodes to all four extremities as per the manufacturer’s
code.
b. place suction electrodes at appropriate sites (at figure)
v1-4th intercostals space on the right side, parasternal.
V2-4th intercostals space on the left side, parasternal.
V3-midway between v2 and v4
V4-5th intercostals space on side in the anterior axillary line.
V6-5th intercostals space on left side in the mid-axillary line.
11. c. ensure proper contact between the lead and skin.
shaving of the chest may be required in case of male
patients.
Rationale:
Proper contact between skin and electrodes and
proper placement of electrodes are very essential for
obtaining a good recording
8. instruct the patient that you are going to start the
recording and he/she should lie still in the bed
without moving till the recording is complete , which
may take 5-10 minutes.
Rationale:
Patient movement during recording causes artifacts
on ECG record.
12. 9.record the ECG:
a. manual recording :
-record limb leads (I,II,III,AVR,AVL,AVF) by advancing
the medicine settings to the respective leads.
-to record chest leads (V1-V6), advance the suction
electrode to next position after recording each lead.
(ensure that machine is set for chest lead recording)
-recording long lead ll.
b. automatic recording:
place limb as well as chest electrodes in position and
ask for autorecording.
Wipe off the electroconductive gel from electrodes.
13. 10.Check the ECG record for appropriateness and
presence of artificates, if any.
Rationale
In case of appropriate recording or presence of
artificates, recording needs to be repeated.
11.Inform patient that ECG recording is completed.
12. Remove electrodes from all limbs and chest
wipe off the electroconductive gel using tissue
papers. Assist patient in dressing.
14. 13.Wipe off the electroconductive gel from electrodes
Rationale
After drying, the gel forms a crust over the electrodes
which may interfere with future recording
14.label the ECG:
a. write patient’s full name, inpatient/outpatient number,
date and time of recording.
b. record lead identification in case of manual record.
c. a standard lead should be labeled and pasted on ECG
card when manual record are obtained.
Rationale
Provide accurate identification data.
15. 15. read and report ECG as follows:
a. rhythm
b. conduction intervals.
c. cardiac axis
d. a discription of the QRS complexes.
e. a description of the ST segments and T waves
Rationale
Helps to identify obvious gross abnormalities.
16. show ECG record to physician as soon as possible so what
further treatment orders can be obtained, if any.
16. The two types of ECG recordings are the 12-lead ECG and a
rhythm strip. Both types give valuable information about
Heart function. The six limb
leads—I, II, III, augmented vector right (aVR), augmented vector
left (aVL), and augmented vector foot (aVF)—provide
information.about the heart’s frontal (vertical) plane. Leads I, II,
and III require a negative and positive electrode for monitoring,
those leads bipolar. The augmented leads record information
from
one lead and are called unipolar.
The six precordial or V leads—V1, V2, V3, V4, V5, and V6—
provide
information about the heart’s horizontal plane.
17. The horizontal axis of the ECG strip represents time. Each
small block equals 0.04 second, and five small blocks form
a large
block, which equals 0.2 second. This time increment is
determined
by multiplying 0.04 second (for one small block) by 5, the
number
of small blocks that compose a large block
18. The ECG strip’s vertical axis measures amplitude in
millimeters
(mm) or electrical voltage in millivolts (mV). Each small
block represents 1 mm or 0.1 mV; each large block, 5 mm or
0.5
mV.
19. Elecplacement in 12 lead ECG electrode :
6 are chest electrodes
Called V1-6 or C1 -6
4 are limb electrodes:
.Right arm:red
.Left arm: yellow
.Left leg:green
.Right leg: black
20. How to work:
The 12-lead ECG records the heart’s electrical activity using a
series of electrodes placed on the patient’s extremities and
chest wall. The 12 leads include three bipolar limb leads (I, II,
and III),vthree unipolar augmented limb leads (aVR, aVL, and
aVF), and six unipolar precordial, or chest, leads (V1, V2, V3,
V4, V5, and V6). These leads provide 12 different views of the
heart’s electrical activity.
23. Leads I, II and III are called the limb leads. The
electrodes that form these signals are located on the
limbs—one on each arm and one on the left leg. The
limb leads form the points of what is known
as Einthoven's triangle.
Lead I is the voltage between the (positive) left arm
(LA) electrode and right arm (RA) electrode
Lead II is the voltage between the (positive) left leg
(LL) electrode and the right arm (RA) electrode
Lead III is the voltage between the (positive) left leg
(LL) electrode and the left arm (LA) electrode
24. Rate and rhythm
In a normal heart, the heart rate is the rate in which the sinoatrial
node depolarizes as it is the source of depolarization of the heart. Heart
rate, like other vital signs like blood pressure and respiratory rate,
change with age. In adults, a normal heart rate is between 60 and 100
beats per minute (normocardic) where in children it is higher. A heart rate
less than normal is called bradycardia (<60 in adults) and higher than
normal is tachycardia (>100 in adults). A complication of this is when the
atria and ventricles are not in synchrony and the "heart rate" must be
specified as atrial or ventricular (e.g., atrial rate in atrial fibrillation is 300–
600 bpm, whereas ventricular rate can be normal (60–100) or faster
(100–150)).
25. In normal resting hearts, the physiologic rhythm of the
heart is normal sinus rhythm (NSR). Normal sinus
rhythm produces the prototypical pattern of P wave,
QRS complex, and T wave. Generally, deviation from
normal sinus rhythm is considered a cardiac
arrhythmia. Thus, the first question in interpreting an
ECG is whether or not there is a sinus rhythm. A
criterion for sinus rhythm is that P waves and QRS
complexes appear 1-to-1, thus implying that the P
wave causes the QRS complex.
Once sinus rhythm, or not, is established the second
question is the rate. For a sinus rhythm this is either
the rate of P waves or QRS complexes since they are
1-to-1. If the rate is too fast then it is sinus
tachycardia and if it is too slow then it is sinus
bradycardia.
26. If it is not a sinus rhythm, then determining the rhythm
is necessary before proceeding with further
interpretation. Some arrhythmias with characteristic
findings:
Absent P waves with "irregularly irregular" QRS
complexes is the hallmark of atrial fibrillation
A "saw tooth" pattern with QRS complexes is the
hallmark of atrial flutter
Sine wave pattern is the hallmark of ventricular flutter
Absent P waves with wide QRS complexes with fast
rate is ventricular tachycardia
27. Normal rhythm produces four entities — a P wave, a
QRS complex, a T wave, and a U wave — that each
have a fairly unique pattern:
The P wave represents atrial depolarization.
The QRS complex represents ventricular
depolarization.
The T wave represents ventricular repolarization.
The U wave represents papillary muscle
repolarization.
28.
29.
30. SPECIAL CONSIDERATIONS
Note that the following can cause poor ECG
signal and or artificates on an ECG record.
Oily, dirty and scaly skin.
Dirty or encrusted electrodes.
Improper application of electrodes.
Loose or dislodged electrodes.
Patient’s movement.
Muscles tremor.
Broken cable wire.
Faulty grounding.
