Cardiac monitoring & ECG

CARDIAC MONITORING & ECG
MATHEW VARGHESE V
MSN(RAK),FHNP (CMC Vellore),CPEPC
Nursing officer
AIIMS Delhi
mathewvmaths@yahoo.co.in

DEFINITION
 The cardiac monitor is a device that shows the
electrical and pressure waveforms of the
cardiovascular system for measurement and
treatment.
 Parameters specific to respiratory function can also
be measured.

PURPOSE
 It continuously shows the cardiac rhythm,heart rate
,BP,RR,&Temp
 It is used in emergency rooms and critical care
areas, for continual observation of critically ill
patients.
 It is useful for observation of postoperative patients,
patients with severe electrolyte imbalances, and
other unstable patients.
 Continuous cardiac monitoring allows for prompt
identification and initiation of treatment for cardiac
arrhythmias and other conditions.
 The cardiac monitor continuously displays the
cardiac electrocardiogram tracing.

PURPOSE
 It also monitor cardiovascular pressures and
cardiac output.
 Oxygen saturation of the arterial blood can also be
monitored continuously.
 It can be interconnected in critical care areas to
allow for continual observation of several patients
from a central display.
 Continuous cardiovascular
and pulmonary monitoring allows for prompt
identification and initiation of treatment.

DESCRIPTION
CM
HR
CVP
ECG
CO
ETco2BP
Temp
Spo2
RR

EQUIPMENT REQUIRED
Cardiac monitor
Monitor cable
Pressure transducers & BP Cuff
Electrodes
Spo2 Probe
Alcohol Sponges
Dry Gauze

FUNCTIONS OF CARDIAC MONITOR
The monitor function includes:
 A display of heart rate and rhythm
 Sound alarms above or below pre-set
limits
 The provision of rhythm strips to
document evidence of arrhythmia

INDICATION OF CARDIAC MONITORING
 Chest pain
 Palpitations
 Acute Coronary Syndrome – STEMI, NSTEMI, unstable
angina
 Following major surgery – ITU, HDU, cardiac surgery
 Major trauma
 Post cardiac/respiratory arrest
 Acute medical conditions –
 Pulmonary embolus, drug overdose, electrolyte
imbalance
 Unexplained syncope episodes
 Shock
 Undergoing a specific treatment

BASIC FEATURES OF CARDIAC MONITORING
 Static bedside cardiac monitor system:
 ECG signal detected from patient electrodes,
transmitted to oscilloscope /monitor screen via a
monitor lead cable
 Displays ECG rhythm continuously
 ECG maybe duplicated to a central console
monitoring station
 Some systems incorporate computerised
software that recognises life threatening cardiac
arrhythmias, sounds an alarm, stores data

BASIC FEATURES OF CARDIAC MONITORING
 Telemetry monitoring: portable wireless cardiac
monitoring system:
 Allows transmission of the ECG without requiring the
patient to be attached to a static monitor
 A patients standard chest electrodes and lead cable are
connected to small portable monitor transmitter carried
in a chest harness /pyjama pocket
 Cardiac rhythm is transmitted to a receiver unit at
central monitoring station where the rhythm is displayed
continuously
 Suitable for Ambulatory cardiac patients requiring
ongoing ECG monitoring
 The device is battery powered

NURSES RESPONSIBILITY
 All electrical equipment and outlets are grounded to
avoid electrical shock and artifact (electrical activity
caused by interference).
 The nurse should plug in the monitor, turn on power, and
connect the cable if not already attached.
 He or she should connect the lead wires to the proper
position and ensure that color-coded wires match the
color-coded cable.
 If the device is not color coded, the right arm (RA) wire
should be attached to the RA outlet, the left arm (LA)
wire attached to the LA outlet, and so forth.
 The nurse should open the electrode package, and
attach an electrode to each lead wire. The hands should
be washed and the procedure should be explained to
the patient.

 Privacy should be ensured for the patient, and the
patient should be clean and dry to prevent electrical
shock.
 Next, the chest should be exposed and the sites
selected for electrode placement.
 Using the rough patch on the electrode, a dry
washcloth, or gauze pad, each site should be
rubbed briskly until it reddens, but care should be
taken not to damage or break the skin.
 Dead skin cells are removed in this manner,
thereby promoting better electrical conduction.
 Patients who are extremely hairy may need to be
shaved prior to application of the electrodes.

 An alcohol pad is used to clean the sites in patients
with oily skin.
 Areas should dry completely to promote good
adhesion.
 Alcohol should not become trapped beneath the
electrode, as this can lead to skin breakdown.
 In addition to oily skin, diaphoretic skin can cause
interference in the recording. To minimize this
interference, the electrode site should be rubbed
with a dry 4×4 gauze pad before application.
 The backing of the electrode should be removed,
and the gel inspected.

 If the electrode has dried out, which can happen if the
electrode package is opened before immediate use, it
should be discarded and another used.
 The nurse should apply one electrode to each site,
press one side of the electrode against the skin, and pull
gently.
 Then, the opposite side of the electrode should be
pressed against the skin.
 The nurse should press two fingers on the electrode in a
circular pattern to affix the gel and stabilize the
electrode, then repeat for each electrode.
 To avoid potential artifact, do not place the electrodes on
bony prominences or hairy areas.

AFTERCARE
 After placing all electrodes, the nurse should observe
the monitor and evaluate the quality of the tracing,
making size and tracing position adjustments as
needed.
 He or she should confirm that the monitor is detecting
each heartbeat by taking an apical pulse and comparing
the pulse to the digital display.
 The upper and lower alarm limits should be set
according to institutional policy, and the alarm activated.
 A rhythm strip should be recorded for the medical
record, and labeled with patient name, room number,
date, time, and interpretation of the strip.

COMPLICATIONS
 There is a potential for skin breakdown at the
electrode placement site.
 The patient may be allergic to the adhesive used, or
the electrode may have been left on the skin too
long.
 The electrodes should be removed and new
electrodes applied, using hypoallergenic electrodes
if necessary.

RESULTS
 A normal cardiac tracing shows a regular rate and
rhythm with no deviations in the QRST complex
(the combined waves of an electrocardiogram).
 Abnormal results may include bradycardia, or
tachycardia, accompanied by the alarm.
 Q waves (the short initial downward stroke of the
QRST complex) are abnormal, and may or may not
signal an infraction.

RESULTS
 Some causes of non infarction Q waves are:
 ventricular hypertrophy
 ventricular preexcitation (Wolff-Parkinson-White
syndrome)
 cardiomyopathies
 pulmonary embolism
 incomplete left bundle branch block

CAUSES OF CHANGES IN ST SEGMENT/T
INVERSION
 Aberrant conduction
 Amyloidosis
 Bundle branch block
 Cardiomyopathy
 Cocaine vasospasm
 Electrolyte disturbances
 Intracranial hemorrhage
 Myocardial metastases
 Myocarditis
 Paced rhythm
 Pancreatitis or acute abdomen

CAUSES OF CHANGES IN ST SEGMENT/T
INVERSION
 Pericarditis
 Physical training
 Printzmetal's angina
 Pulmonary embolism
 Tachycardia
 Ventricular aneurysm
 Ventricular hypertrophy
 Ventricular rhythms
 Wolff-Parkinson-White syndrome

RESULTS
 Alarm signals are abnormal and must be investigated.
 A false high alarm rate may be caused by skeletal
muscle activity or by the monitor incorrectly interpreting
large T waves as a QRS complex, which would double
the true heart rate.
 The electrodes should be repositioned as needed to
ensure that the electrode is not over a major muscle
mass and that QRS complex is larger than the T wave.
 A false low alarm rate may be due to patient movement,
or poor contact between electrodes and skin.


RESULTS
 Electrodes should be reapplied as needed.
 Artifact is a common abnormal finding, and may be
caused by improperly placed electrodes, patient
movement, static electricity seizures, anxiety, or
chills.
 The position of electrodes should be checked and
static-causing bed linen changed. The cables
should not have exposed connectors.

STANDARD 12-LEAD ELECTROCARDIOGRAM
 A graphical recording of the electrical activity of the
heart over time
 Gold standard for diagnosis of cardiac arrhythmias
 Helps detect electrolyte disturbances (hyper- &
hypokalemia)
 Allows for detection of conduction abnormalities
 Screening tool for ischemic heart disease during
stress tests
 Helpful with non-cardiac diseases (e.g. pulmonary
embolism or hypothermia )

WILLIAM EINTHOVEN – FATHER OF ECG

SIGNIFICANCE
 ECG gives information about rate and rhythm of the
heart.
 The physical orientation of heart i.e axis.
 Its a diagnostic tool for various heart conditions like
hypertrophies , ischemia, infarction , arrhythmias
conduction problems and pace maker activity.
 ECG does not provide information about
mechanical activity

ECG GRAPH PAPER
 Runs at a paper speed of 25 mm/sec
 Each small block of ECG paper is 1 mm2
 At a paper speed of 25 mm/s, one small block
equals 0.04 s
 Five small blocks make up 1 large block which
translates into 0.20 s (200 msec)
 Hence, there are 5 large blocks per second
 Voltage: 1 mm = 0.1 mV between each individual
block vertically

ECG PAPER

RECORDING OF THE ECG: LEADS
6
LIMB LEADS 6
CHEST LEADS

LIMB LEADS
3
UNIPOLAR
3
BIPOLAR

BIPOLAR LEADS
LEAD
I
LEAD
II
LEAD
III

EINTHOVEN’S TRIANGLE

BIPOLAR LEADS
 Lead I is the voltage between the (positive) left arm
(LA) electrode and right arm (RA) electrode:{I=LA-
RA}
 Lead II is the voltage between the (positive) left leg
(LL) electrode and the right arm (RA)
electrode:{II=LL-RA}
 Lead III is the voltage between the (positive) left leg
(LL) electrode and the left arm (LA)
electrode:{III=LL-LA}

EINTHOVEN'S LAW
 If ELECTROCARDIOGRAMS are taken simultaneously with
the three limb LEADS, at any given instant the POTENTIA
L in lead II is equal to the sum of the potentials in leads
I and III.
 LEAD I + LEAD III = LEAD II

LIMB ELECTRODES
 LA – left arm
 RA – right arm
 LL – left leg
 RL – right leg – neutral – not used in
measurements

UNIPOLAR LEADS – AUGMENTED LEADS
aVL
aVF
aVR

AUGMENTED LEADS
 These leads are unipolar in that they measure the
electric potential at one point with respect to a null
point
 This null point is obtained for each lead by adding
the potential from the other two leads.
 For example, in lead aVR, the electric potential of
the right arm is compared to a null point which is
obtained by adding together the potential of lead
aVL and lead aVF

CHEST LEADS OR PRECORDIAL LEADS
 V1 (fourthIntercostal space, right sternal border)
 V2 (fourth intercostal space, left sternal border)
 V3 (diagonally between V2 and V4)
 V4 (fifth intercostal space, left midclavicular line)
 V5 (same horizontal line as V4 in left anterior axillary line)
 V6 (same horizontal line as V4 and V5, in midaxillary line).

ECG INTERPRETATION -PARTS OF AN ECG

NORMAL ECG

NORMAL ECG CONTAINS
 Wave: A positive or negative deflection from
baseline that indicates a specific electrical event.
The waves on an ECG include the P wave, Q wave,
R wave, S wave, T wave and U wave.
 Interval: The time between two specific ECG
events. The intervals commonly measured on an
ECG include the PR interval, QRS interval (also
called QRS duration), QT interval and RR interval.

NORMAL ECG CONTAINS
 Segment: The length between two specific points
on an ECG that are supposed to be at the baseline
amplitude (not negative or positive). The segments
on an ECG include the PR segment, ST segment
and TP segment.
 Complex: The combination of multiple waves
grouped together. The only main complex on an
ECG is the QRS complex
 Point: There is only one point on an ECG termed
the J point, which is where the QRS complex ends
and the ST segment begins.

APPROACH TO ECG INTERPRETATION
 The standard 12-lead ECG is a 10-second strip.
The bottom one or two lines will be a full “rhythm
strip” of a specific lead, spanning the whole 10
seconds of the ECG. Other leads will span only
about 2.5 seconds.
 Each ECG is divided by large boxes and small
boxes to help measure times and distances. Each
large box represents 0.20 seconds, and there are
five small boxes in each large box, thus each small
box is equivalent to 0.04 seconds. The image below
depicts each of these.

THE STANDARD APPROACH TO READ AN ECG
Examining the rate
Examining the rhythm
Examining the axis
intervals and segments
Examining everything
else

FORMULA TO CALCULATE HR
 Formula to calculate HR (If the rhythm is
regular)
HR= 1500/ No of Small Squares
between two R-R interval
HR= 300/ No of large Squares
between two R-R interval

P WAVE
 The P wave indicates atrial depolarization. The P
wave occurs when the sinus node, also known as
the senatorial node, creates an action potential that
depolarizes the atria. The P wave should be upright
in lead II if the action potential is originating from
the SA node

P WAVE: 5 QUESTIONS TO ASK
 1.Are P waves present?
 2.Are P waves occurring regularly?
 3.Is there one P wave present for every QRS
complex present?
 4.Are the P waves smooth, rounded, and upright in
appearance, or are they inverted?
 5.Do all P waves look similar?

P WAVE – NORMAL VALUES
Amplitude: 2-3 mm high
Deflection: + in I, II, AVF, V2-V6
- in AVR & V1
Duration: 0.06 - 0.12 sec

PR SEGMENT
 The PR segment is the portion of the ECG from the
end of the P wave to the beginning of the QRS
complex.
 The PR segment is different from the PR interval,
which is measured in units of time.
 Although abnormalities of the PR segment are not
very common, they can indicate certain cardiac
disease states.
 PR segment depression can be a signal for
pericarditis or atrial infarction. PR segment
elevation occurs in lead aVR in the setting
of pericarditis

PR INTERVAL-FROM ONSET OF P WAVE TO
ONSET OF QRS
 Measures the time interval from the onset of atrial contraction
to onset of ventricular contraction
 Normal duration = 0.12-2.0 sec (120-200 ms) (3-4 horizontal
boxes)
 Represents atria to ventricular conduction time (through His
bundle
 Prolonged PR interval may indicate a 1st degree heart block

PR INTERVAL: 3 QUESTIONS TO ASK
1.Are the PR intervals greater than 0.20 seconds?
2.Are the PR intervals less than 0.12 seconds?
3.Are the PR intervals consistent across the EKG
strip?

Q WAVE
 The Q wave is the first downward deflection after the P
wave and the first element in the QRS complex.
 When the first deflection of the QRS complex is upright,
then no Q wave is present.
 The normal individual will have a small Q wave in many,
but not all, ECG leads.
 Abnormalities of the Q waves are mostly indicative of
myocardial infarction .
 The terms “Q wave myocardial infarction” and “non-Q
wave myocardial infarction” are earlier designations of
different types of MIs ultimately resulting in, respectively,
Q wave development or the absence of Q wave
development.

R WAVE
 The R wave is the first upward deflection after the P
wave and part of the QRS complex.
 The R wave morphology itself is not of great clinical
importance but can vary at times.
 The R wave should be small in lead V1.
 Throughout the precordial leads (V1-V6), the R
wave becomes larger — to the point that the R
wave is larger than the S wave in lead V4. The S
wave then becomes quite small in lead V6; this is
called “normal R wave progression.”
 When the R wave remains small in leads V3 to V4
— that is, smaller than the S wave — the term
“poor R wave progression” is used.

R WAVE
 The causes for a R/S wave ratio greater than 1 in
lead V1 include right bundle branch block, Wolff-
Parkinson-White syndrome, an acute posterior
myocardial infarction, right ventricular hypertrophy
and isolated posterior wall hypertrophy.
 If a right bundle branch block is present, there may
be two R waves, resulting in the classic “bunny ear”
appearance of the QRS complex. In this setting, the
second R wave is termed “R prime.”

BUNNY EAR OR RABBIT EAR

S WAVE
 The S wave is the first downward deflection of the
QRS complex that occurs after the R wave.
 In the normal ECG, there is a large S wave in V1
that progressively becomes smaller, to the point
that almost no S wave is present in V6.
 A large slurred S wave is seen in leads I and V6 in
the setting of a right bundle branch block.

QRS COMPLEX
 Amplitude: 5-30 mm high
Deflection: + in I, II, III, AVL, AVF, V4-V6
 A combination of the Q wave, R wave and S wave, the
“QRS complex” represents ventricular depolarization.
 This term can be confusing, as not all ECG leads
contain all three of these waves; yet a “QRS complex” is
said to be present regardless.
 For example, the normal QRS complex in lead V1 does
not contain a Q wave — only a R wave and S wave —
but the combination of the R wave and S wave is still
referred to as the QRS complex for this lead.

QRS COMPLEX
 The normal duration (interval) of the QRS complex
is between 0.06 and 0.10 seconds — that is, 60
and 100 milliseconds.
 When the duration is between 0.10 and 0.12
seconds, it is intermediate or slightly prolonged.
 A QRS duration of greater than 0.12 seconds is
considered abnormal.
 A widened QRS duration occurs in the setting of a
right bundle branch block, left bundle branch block,
non-specific intraventricular conduction delay and
during ventricular arrhythmias such as ventricular
tachycardia

T WAVE
 The T wave occurs after the QRS complex and is a
result of ventricular repolarization.
 T waves should be upright in most leads; the
exceptions are aVR and V1.
 Further, T waves should be asymmetric in nature.
 The second portion of the T wave should have a
steeper decline when compared with the incline of
the first portion.
 If the T wave appears symmetric, cardiac
pathology such as ischemia may be present

T WAVE
 Amplitude: 0.5 mm in limb leads
Deflection: I, II, V3-V6

QT INTERVAL
 The QT interval is the time from the beginning of
the QRS complex, representing ventricular
depolarization, to the end of the T wave, resulting
from ventricular repolarization.
 The normal QT interval is controversial, and
multiple normal durations have been reported.
 In general, the normal QT interval is below 400 to
440 milliseconds (ms), or 0.4 to 0.44 seconds.
 Women have a longer QT interval than men.
 Lower heart rates also result in a longer QT
interval.

QT INTERVAL
 Prolongation of the QT interval can result from
multiple medications, electrolyte abnormalities —
hypocalcemia, hypomagnesemia
and hypokalemia — and certain disease states
including intracranial hemorrhage.

ST SEGMENT
 The ST segment is the portion of the ECG from the
end of the QRS complex to the beginning of the T
wave.
 The ST segment normally remains isoelectric, thus
ST segment depression or ST segment elevation
can indicate cardiac pathology.
 The ST segment is scrutinized on the ECG for the
detection of myocardial ischemia.
 This can be done in the setting of either exercise or
pharmacologic stress testing.

TP SEGMENT
 The TP segment is the portion of the ECG from the end
of the T wave to the beginning of the P wave.
 This segment should always be at baseline and is used
as a reference to determine whether the ST segment is
elevated or depressed, as there are no specific disease
conditions that elevate or depress the TP segment.
 During states of tachycardia, the TP segment is
shortened and may be difficult to visualize altogether.
 It is good to examine the TP segment closely for the
presence of U waves or atrial activity that could indicate
pathology.

U WAVE
 Usually not visible on EKG strips
 If visible, typically follows the T wave
 Appears much smaller than T wave, rounded,
upright, or positive deflection is they are present
 Cause or origin not completely understood
 May indicate hypokalemia

DETERMINING AXIS
 The axis of the ECG is the major direction of the
overall electrical activity of the heart.
 It can be normal, leftward (left axis deviation, or
LAD), rightward (right axis deviation, or RAD) or
indeterminate (northwest axis).
 The QRS axis is the most important to determine.
 However, the P wave or T wave axis can also be
measured.
 To determine the QRS axis, the limb leads (not the
precordial leads) need to be examined

AXIS
 Lead I is at zero degrees, lead II is at +60 degrees,
and lead III is at +120 degrees. Lead aVL (L for left
arm) is at -30 degrees and lead aVF (F for foot) is
at +90 degrees. The negative of lead aVR (R for
right arm) is at +30 degrees; the positive of lead
aVR is actually at -150 degrees.

AXIS
 The normal QRS axis should be between -30 and
+90 degrees.
 Left axis deviation is defined as the major QRS
vector, falling between -30 and -90 degrees.
 Right axis deviation occurs with the QRS axis and
is between +90 and +180 degrees.
 Indeterminate axis or Northwest axis is between +/-
180 and -90 degrees.

NORMAL QRS AXIS
 If the QRS complex is upright (positive) in both lead
I and lead aVF, then the axis is normal.
 .

LEFT AXIS DEVIATION

CAUSES OF LAD
 Left anterior fascicular block
 Left ventricular hypertrophy (rarely with LVH;
usually axis is normal)
 Left bundle branch block (rarely with LBBB)
 Mechanical shift of heart in the chest (lung disease,
prior chest surgery, etc.)
 Inferior myocardial infarction
 Wolff-Parkinson-White syndrome with
“pseudoinfarct” pattern
 Ventricular rhythms (accelerated
idioventricular or ventricular tachycardia)
 Ostium primum atrial septal defe

THE CAUSES OF RAD.
 If the QRS is predominantly negative in lead I and
positive in lead aVF, then the axis is rightward (right axis
deviation).
 Right bundle branch block
 Right ventricular hypertrophy
 Left posterior fascicular block
 Dextrocardia
 Ventricular rhythms (accelerated
idioventricular or ventricular tachycardia)
 Lateral wall myocardial infarction
 Wolff-Parkinson-White syndrome
 Acute right heart strain/pressure overload — also known
as McGinn-White Sign or S1Q3T3 that occurs
in pulmonary embolus

S1Q3T3 PATTERN

INDETERMINATE AXIS

NURSES ROLE- PREPARATION
 The first duty of the nurse is to prepare the patient
to receive the electrodes attached to the monitoring
machine.
 The nurse must make sure that the area to which
the electrodes are to attach is clean and free of
hair.
 This responsibility may involve the washing and/or
shaving of the patient.

AFFIXING ELECTRODES
 The nurse affixes the electrodes to the patient. This
is a crucial step—improper placement of the
electrodes could lead to inaccurate results.
 As lives depend on these delicate machines, it is
important that this is done correctly.
 There are specific areas of the skin on which
electrodes must be placed in order to ensure
accuracy.
 These locations include the right and left arms,
right and left legs, as well as various locations
along the rib cage.

REFERENCE
 https://www.urmc.rochester.edu/encyclopedia/content
 https://web2.aabu.edu.jo/tool/course_file/1001326_mort
on_ch17_Part1
 https://accessmedicine.mhmedical.com/content.aspx
 https://www.ncbi.nlm.nih.gov/books/NBK393
 https://www.hopkinsmedicine.org/healthlibrary/.../cardiov
ascular_diseases/cardiac_di
 https://www.mayoclinic.org/diseases-conditions/heart-
disease/diagnosis.../drc-203
 https://www.emedicinehealth.com/electrocardiogram_ec
g/article_em.htm#anatomy_of_the_heart
 https://www.healio.com/cardiology/learn-the-heart/ecg-
review/ecg-interpretation-tutorial/introduction-to-the-ecg

Cardiac monitoring & ECG

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

Ähnlich wie Cardiac monitoring & ECG

Ähnlich wie Cardiac monitoring & ECG (20)

Mehr von Mathew Varghese V

Mehr von Mathew Varghese V (20)

Kürzlich hochgeladen

Kürzlich hochgeladen (20)

Cardiac monitoring & ECG