Nursing Interpretation of the
Electrocardiogram (ECG), Telemetry
By: Teresa Champion
MCC
NURS 2140
OBJECTIVES
• Describe the configuration of the normal electrocardiogram
(ECG).
• Identify and calculate heart rate, rhythm, PR interval, QRS
complex, and QT interval for normal and abnormal cardiac
rhythms.
• Discuss the etiology and significant ECG features of the
following dysrhythmia classifications: sinus, atrial, junctional,
block, ventricular, and asystole.
• Interpret the significance of each of the dysrhythmias and
formulate nursing responsibilities for each dysrhythmia.
• Identify normal rhythms and dysrythmias.
• Identify ECG complexes and artifact.
• Perform ECG rhythm strips.
• Identify correct dysrythmia terminology
Cardiac Conduction System
–3 Main Parts:
• SA node (Sinoatrial node)
• AV node (Atrialventricla
node)
• HIS-Perkinje System
VIDEO OF CONDUCTION SYSTEM
http://www.nhlbi.nih.gov/health/dci/Disease
s/hhw/hhw_electrical.html
Anatomy of the Heart - CARDIAC CELLS
• Two types of cardiac cells
– Myocardial & Pacemaker cells
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Automaticity
Excitability
Conductivity
Contractility
Anatomy of Heart – Cardiac Chemistry
Function
• Electrolytes Affecting Cardiac Function
• Depolarization/Repolarization
• Cardiac Output (CO): The amount of blood the
heart pumps out to body in 1 min.
NORMAL: 5 to 8 L
• CO= HR x SV (CO can be changed by altering
heart rate, stroke vol. or both)
• Stroke Volume = the amount of blood that the
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heart ejects in one beat which
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depends on activity level, physical
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condition, prior heart disease
Cardiac Wave Form on Electrocardiogram
(ECG)
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P wave
PR interval
QRS complex
J point
ST Segment
T wave
QT Interval
R to R Interval
U wave (not always present)
ECG Wave Form
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ECG Lead Placement in Telemetry
• 1. The white lead is placed on the right side of
the chest. This is usually called the “right arm
lead.”
• 2. The black lead is placed on the left side of the
chest. This is called the “left arm lead.”
• 3. The green lead is placed on the right lower
abdomen, it is called the “right leg lead.”
• 4. The red lead is placed on the right lower
abdomen, it is called the “left leg lead.”
• 5. The brown lead is placed slightly to the right of
the midsternum, it is called the “V lead or chest
lead.”
• 6. The grey lead is
Lead Placement ECG Telemetry
White
lead
Black
Lead
Brown
Lead
Green
Lead
Red
Lead
ECG Graph Paper
Heart Rate on ECG
• Heat Rate
– Fastest count R waves in 6 second
strip and times by 10.
– Count R waves on a full minute strip
for accurate HR for irregular rhythms.
– Another way is to count the number of
small boxes between R waves and
divide the total by 1500.
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big box (5 small boxes) is equal to a HR of 300
big boxes is hr of 150 (300/2)
big boxes is hr of 100 (300/3)
big boxes is hr of 75 (300/4)
big boxes is hr of 60 (300/5)
big boxes is hr of 50 (300/6)
big boxes is hr of 43 (300/7)
big boxes is hr of 38 (300/8)
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Large box estimate of heart rate works with
regular rhythms
• A dysrhythmia is a disturbance of the rhythm
of the heart caused by a problem in the
conduction system.
• Categorized by site of origin: atria , AV nodal,
ventricular
• Blocks are interruptions in impulse
conduction: 1st, 2nd type 1&2, 3rd or complete
heart block
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P wave
Measures:
0.12-0.20
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QRS WAVE
Measures:
0.06-0.10
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QT Wave
Measures
approx 0.360.48 seconds
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Heart rates
• NSR: heart rate is 60-100bpm
• ST: heart rate 101-180 bpm
• SB: heart rate <60 bpm
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Sinus rhythm
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PR interval- 0.12-0.20sec
QRS-0.06-0.10sec
QT segment 0.36-0.44 sec
Heart rate 60-100
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Atrial arrhythmias
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Sinus tachycardia
Atrial tachycardia
Sinus bradycardia
Premature atrial contraction (PAC)
Supraventricular tachycardia
Atrial fibrillation
Atrial flutter
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Sinus Tachycardia
Atrial Tachycardia
Sinus Bradycardia
Premature Atrial Contraction (PAC)
SupraVentricular Tachycardia
(SVT)
Atrial Fibrillation (Afib)
Atrial Flutter
Atrial fib/flutter
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Other Atrial Dysrhymias
• Wolf Parkingson-White Syndrome (WPW)
• Wandering Atrial Pacemaker (WAP)
• Sick Sinus Syndrome (SSS)
Management of Atrial Dysrhymias
• Assess pt response/Monitor Vital Signs
• May cause drop in Cardiac Output (CO)
• Notify MD (Health Care Practitioner)
– Intervention to convert back to NSR
• Increase rate – slow rates, Administer drugs
(Atropine), Transcutaneous Pacing
– Control rate – if fast Ventricular Response
(ie: A-fib, SVT, Aflutter)
– Anticoagulate
– Cardioversion
How to treat SVT
• B-blockers ( to decrease conduction thru AV
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node:
• Calcium channel blockers ( to decrease conduction
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thru AV node)
• Radio frequency ablation
• SVT converted with Adenosine
given rapid IV Push stimulates vagal
response.
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Atrial Fibrillation
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- - 5 to 6 times more likely to have stroke
- - atrial rate: 300 to 600 times/minute
--prolonged A-Fib may stretch & weaken
heart muscle
- - symptoms: lightheaded, very tired,
SOB, diaphoretic, chest
pain,
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A Fib electrical cardioversion:
• High risk of forming clots & causing stroke
• Anticoagulants taken before treatment and 34 weeks post treatment
• If life-threatening, may need Heparin IV
before cardioversion
• Best time: recent A fib
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Ventricular arrythmias
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Junctional rhythms
AV blocks
Premature ventricular contraction (PVC)
Ventricular Tachycardia (V-tach)
Ventricular Fibrillation (V-Fib)
Torsade de Pointes (TdP)
Pulseless electrical activity (PEA)
Asystole
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Junctional Escape Rhythm
Accelerated Junctional Rhythm
AV Blocks
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First degree block
Second degree block Type I (Wenchebach)
Second degree block Type II (Mobitz II)
Third degree block
Bundle branch block
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Rate is usually WNL
Rhythm is regular
Pwaves are normal in size and shape
The PR interval is prolonged (>0.20 sec) but constant
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Pwaves are normal in size and shape;
Some pwaves are not followed by QRS
PR interval: lengthens with each cycle until it appears without QRS Complex
then the cycle starts over
QRS is usually narrow
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http://www.youtube.com/watch?v=GVxJJ2
DBPiQ&feature=related
•Ventricular rate is usually slow
•Rhythm is irregular
•Pwaves are normal in size and shape (more
pwaves than QRS)
•PR interval is within normal limits
•QRS is usually wide
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•Ventricular rate is regular but there is no
correlation between p-waves and QRS
•P waves are normal in size and shape
•No true PR interval
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PVC
Unifocal
Multifocal
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PVC: ventricular origin
• Complex is wide followed by compensatory
pause
• An irritable focus in ventricle initiates a
contraction before normally expected beat.
• Acute MI most common cause
• QRS is wide and bizarre
• Risks: increasing myocardial irritability,
leading to increased freq. of PVCs
• Can occur as bigeminy (every other beat)
• or short runs
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Ventricular tachycardia
Monomorphic: beats are same size and shape
Polymorphic: different size and shape
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This is a polymorphic VT
Usually electrical imbalance in r/t
NA+ or K+
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V-tach
• Advanced irritability of ventricles due to
ASHD, CHF, acute MI electrolyte imbalance.
Hypoxia, acidosis, occasionally drugs
• RISKS: low to no Cardiac output
• Nursing Interventions: monitor, if pt
unconscious, immediately defibrillate
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Torsade de pointes
• Will see prolonged QT interval when in sinus
rhythm
• Will see prominent U wave
• If lasts >10 seconds pt will progress to
unconsciousness, life threatening with ineffective
cardiac output
• TREATMENT: IV magnesium
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Ventricular Fibrillation (Course)
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Ventricular Fibrillation (Fine)
Vtach/Vfib
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Both can be life threatening
VT= V HR 100-250 bpm
Causes: AMI, CAD, hypokalemia, dig toxic
S/S: palpitations, dizzy, angina, <LOC
Treatment: assess for pulse, if none, defibrillate
• VF=Rate undeterminable Cause: same
• Treatment: CPR, Defibrillate
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V-fib
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May occur after MI
Extensive ventricular irritability
Very little or no cardiac output (No Pulse)
Death within 4 to 8 minutes
TREATMENT: immediate defibrillation
immediate defibrillation at 200 J (100J)
if unsuccessful, repeat at 300 J (150J)
If unsuccessful, repeat at 360 J (200J)
CPR
If do not know type of defibrillator start at
200J
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Asystole
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Pulsless Electrical Activity (PEA)
Asystole and PEA
• CPR
Oxygen
• Epinephrine 1 mg IV/IO (repeat 3-5 minutes)
• May give Vasopressin 40U IV/IO to replace
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1st or 2nd dose of epinephrine
• Consider Atropine 1 mg IV/IO Repeat every 3 to 5
min (up to 3 doses)
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Pacer spike should fall before the P wave unless a dual
Chamber pacemaker; if it does not there could be a problem
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ARTIFACT
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http://www.campaignfornursing.com/events/WINNERS/pennsylvania/
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