Title: EKG Code Lab
1EKG / Code Lab
- NURS 228
- Janie Best, RN, MSN, ACNS-BC
2Objectives
- Apply appropriate nursing interventions for
selected dysrhythmias. - Analyze professional and legal dimensions that
guide a nurses responsibilities during a code,
including DNR status
3Types of Cardiac Cells
- Myocardial cells
- Working or mechanical cells
- Contain contractile filaments
- Pacemaker cells
- Specialized cells of the electrical conduction
system - Responsible for the spontaneous generation and
conduction of electrical impulses
4 Properties of Cardiac Cells
- Excitability
- Muscle cells can respond to outside stimulus
- Automaticity
- Pacemaker cells spontaneously initiate an
electrical impulse without being stimulated from
another source - Conductivity
- Cardiac cells can receive an electrical stimulus
and conduct it to adjacent cardiac cell - Contractility
- Muscle contraction in response to electrical
stimulus
5Cardiac Conduction
6Skin Preparation
- Clean skin where electrodes will be applied
- Rub electrode site with alcohol
- Removes oil, lotion, powder from skin
- Shave any hair from electrode site
- Improves conductivity
- Electrodes remove easier
- Can apply skin prep to site
- Protects skin site in fragile skin
- Apply electrode
- Remove electrodes after use
- Use adhesive remover or moist cloth
7Lead Placement 5 lead system
From Basic ECG Module - AACN
8ECG Paper
- ECG paper is graph paper made up of small and
larger, heavy-lined squares - Smallest squares are 1 mm wide and 1 mm high
- 5 small squares between the heavier black lines
- 25 small squares within each large square
9What Does the ECG Measure?
V O LTAGE
T I M E
10ECG Complex
11FIGURE 27-3. E Smeltzer Brunner, 11th Ed. p.
827.
12PR Interval
Normal P wave small, round, upright PR
Interval Begins with the onset of the P wave and
ends with the onset of the QRS complex Normally
measures 0.12 to 0.20 seconds 5 small boxes
13QRS Complex
- A QRS complex normally follows each P wave
- Consists of Q wave, R wave, and S wave
- Represents the spread of electrical impulse
through the ventricles (ventricular
depolarization) - Normal - 0.04 0.12 seconds
14 ST segment T wave
- T wave - Represents ventricular repolarization
- The beginning of the T wave is identified as the
point where the slope of the ST segment appears
to become abruptly or gradually steeper - The T wave ends when it returns to the baseline
- ST Segment - Begins with the end of the QRS
complex and ends with the onset of the T wave and
is on the same line as the PR interval - ST segment depression of more than 1 mm is
suggestive of myocardial ischemia - ST segment elevation of more than 1 mm is
suggestive of myocardial injury or
Pericarditis
15ST Segment
- The ST segment is considered
- Elevated if the segment deviates above the
baseline of the PR segment - Depressed if the segment deviates below it
16From Basic ECG Module - AACN
17ECG and the Cardiac Cycle
ST Segment
Isometric line
18ECG Practice Strips
- Identification of the waveforms
19Steps of Rhythm Analysis
- What is the rate?
- Ventricular
- Atrial
- Is the rhythm regular or irregular?
- Is there 1 P wave before each QRS?
- Is the PR interval WNL (.12-.20)?
- Is the QRS narrow or wide (.04-.10)?
- Interpret the rhythm
- Is the rhythm clinically significant?
- Also look at
- ST segment
- T wave
20Determining the Rate
- 1500 of small boxes within an RR interval
(regular rhythms) - 10 x of R complexes in 6 seconds
21Rhythm Regular / Irregular
- Distance between the R waves
22Normal Sinus Rhythm
- Ventricular rate 60-100 Regular rhythm
- Atrial Same as ventricular
- P consistent shape always positive
- P-R interval 0.12-0.20
- QRS complex 0.04-0.10
- 1 P wave for every QRS
23Dysrhythmias
- Disorders of electrical impulse
- Formation
- Conduction
- Named by
- Site of origin of impulse
- Mechanism of formation or conduction involved
24Dysrhythmias
- Site of origin
- SA node
- Bradycardia, Tachycardia
- Atrial tissue
- Flutter, fibrillation
- AV node
- Blocks
- Junctional
- Ventricular tissue
- Tachycardia, fibrillation
25Dysrhythmias
- Mechanism of formation or conduction
- Normal
- Bradycardia
- Tachycardia
- Flutter
- Fibrillation
- Premature complexes
- Conduction blocks
26Tachy-dysrhythmias
- Rate gt 100 bpm (beats per minute)
- Coronary artery blood flow occurs during diastole
(aortic valve closed) - Shorter diastolic time ? coronary artery
perfusion time - ? workload of heart, ? myocardial O2 demand
- CAD (? blood flow)
27Sinus Tachycardia
- Etiology
- ? CNS response Anxiety Pain Fever Anemia
Meds Compensatory hypovolemia - Is client symptomatic?
- Interventions
- Identify cause, Select best Treatment
- Goal ? HR to normal levels
- ASA, ß-blockers, ACE Inhibitors
- Meds of concern
28Sinus Tachycardia
- Ventricular rate gt 100 (up to180) Regular
rhythm - Atrial Same as ventricular
- P consistent shape
- P-R interval Normal
- P wave for every QRS
- QRS complex Normal
29Paroxysmal Supraventricular Tachycardia (PSVT)
Paroxysmal supraventricular tachycardia is a
term used to describe SVT that starts and ends
suddenly
30Bradydysrhythmias
- HR lt 60 bpm
- ? myocardial O2 demand
- Prolongs diastole
- Coronary perfusion pressure may ? if HR too slow
to provide adequate CO BP - If BP adequate, will tolerate slow rate
- If BP not adequate, symptomatic (may lead to
myocardial ischemia, MI, HF)
31Sinus Bradycardia
- Ventricular ratelt 60 regular rhythm
- Atrial same as ventricular
- P consistent shape
- P-R interval Normal
- P wave for every QRS
- QRS complex Normal
32Sinus Bradycardia
- Etiology
- PNS dominant Excessive vagal (Valsalva)
stimulation to the heart (? SA node discharge ?
HR, ? conduction) - Is client symptomatic?
- Interventions
- Atropine Tx of choice
- Volume replacement
- Pacemaker placement
33Flutter and Fibrillation
34Atrial Flutter
- Etiology
- AV node selectively blocks impulses that reach
ventricles (protective mechanism) - Rheumatic Heart disease, CHF, AV valve disease,
post cardiac surgery - Clinical manifestations dependent upon
ventricular response - Interventions
- O2
- Meds amiodarone, Cardizem, verapamil (older and
seldom used drug choice)
35Atrial Flutter
- Ventricular rate Variable, Regular rhythm
- Atrial 250-300/minute, Regular rhythm
- P shape sawtooth formation
- P-R interval Absent
- No P wave
- QRS complex
- Normal
36Atrial Fibrillation
- Etiology
- Most common dysrhythmia in US
- Aging, MI, HF, MS, Cardiomyopathy
- Multiple, rapid impulses many atrial foci Atrial
depolarization disorganized and chaotic - No atrial contraction, Irregular ventricular
response - Can lead to formation of multiple thrombi in
cardiac chambers
37Atrial Fibrillation
- Symptoms
- SOB
- Fatigue
- Weakness,
- Distended neck veins
- Anxiety
- Syncope
- Palpitations
- Chest discomfort
- Irregular pulse
- Commonly seen after cardiac surgery (transient)
- Can be intermittent or chronic
38Atrial Fibrillation
- Interventions
- If initial Atrial fib lt 48 hrs the treatment is
aimed to ? ventricular response convert to NSR - ß-blockers, Ca channel blockers
- Antiarrhythmics (conversion to NSR)
- Cardioversion synchronized countershock
- If in atrial fib gt 48 hrs
- Anticoagulant therapy
39Atrial Fibrillation
- Ventricular rate lt 100 (controlled), irregular
- Atrial Unable to determine (lt 350)
- No P waves (fibrillatory waves)
- P-R interval Absent
- QRS complex Normal
40Atrial Fibrillation
41Premature Ventricular Contractions
- Etiology
- Early ventricular complexes, followed by pause
- Ventricular contraction originating in an ectopic
focus outside ventricles - Aging, MI, HF, Caffeine, ? K
- Assessment
- Asymptomatic or Symptomatic
- Palpitations, Chest Pain (lack of perfusion)
- Can be warning (onset of VT, VF, R on T
phenomenon) AMI
42Premature Ventricular Contractions
- Interrupts basic rhythm
- Occurs early in the R-R cycle
- No P wave w/ PVC
- QRS wide and unusual
PVC
43Premature Ventricular Contractions
- Interventions
- If symptomatic
- Identify eliminate cause
- O2, Antiarrhythmics (lidocaine)
- MONA
- Morphine
- Oxygen
- Nitroglycerine
- ASA
44PVCs
Unifocal PVCs
Multi-focal PVCs
45Refractory The extent to which a cell is able
to respond to a stimulus
- Absolute refractory period
- Onset of QRS complex to approximately peak of T
wave - Cardiac cells cannot be stimulated to conduct an
electrical impulse, no matter how strong the
stimulus - Relative refractory period
- Corresponds with the downslope of the T wave
- Cardiac cells can be stimulated to depolarize if
the stimulus is strong enough
46R on T phenomenon
- Appearance of PVC on T wave of preceding normal
beat - Can lead to Ventricular Fibrillation
- May see with MI
47Ventricular Tachycardia
- Etiology
- Repetitive firing of an irritated ventricular
ectopic focus - Intermittent (NSVT)
- Sustained gt 15-30 sec
- SA node discharges independently (atria
depolarize, not the ventricles AV dissociation) - P waves seldom seen in sustained V Tach
- AMI, CAD, K imbalance, gt QT interval, Cardiac
surgery, Digoxin toxicity
48Ventricular Tachycardia
- Assessment
- Depends on ventricular rate
- Slower rates better tolerated
- Interventions Treat cause
- Sustained
- O2, ECG, Antiarrhythmics (amiodarone)
- Elective cardioversion
- Unstable
- Emergency cardioversion, O2, antiarrhythmics
- Pulseless
- Defibrillation
49Ventricular Tachycardia (V Tach)
- Unable to determine rhythm
- Regular ventricular rate (100-250)
- No P waves present
- QRS complex gt 0.10 sec
50V Tach
Indicates defibrillation
51Ventricular Fibrillation
- Chaotic electrical activity
- No discernable P-QRS-T complexes
- Cardiac arrest
- Etiology
- Ventricles quiver, consume lots of O2, No
cardiac output, no perfusion - AMI, ? K, ? Mg
- Rapidly fatal (3-5 min)
52Ventricular Fibrillation
- Assessment
- LOC, Absence of Pulse
- Apnea
- Seizures
- Development of respiratory metabolic acidosis
- Treatment
- CPR (ACLS)
- Defibrillation
- Drug of choice Amiodarone, Lidocaine, Magnesium
Sulfate (for hypomagnesemia or torsades de
pointes)
53Ventricular Fibrillation (V Fib)
Coarse
Fine
54Asystole
- Ventricular standstill
- Complete absence of any ventricular rhythm
- Etiology
- No electrical impulses, No depolarization
- No cardiac output, VS
- No impulses reach ventricles if SA fires
- Cardiac arrest, Unresponsive
- Intervention ACLS
- Make sure not in Fine V Fib
55Cardioversion / Defibrillation
- Cardioversion
- timed electrical current
- Synchronizes with the ECG so that electrical
impulse discharges during ventricular
depolarization (QRS complex) causing a momentary
delay in discharge of current once the unit is
charged - Defibrillation
- Treatment of choice for pulseless VT and V fib
- Electrical current is not timed (no QRS complex
is present) - Current discharges immediately when charged
56Heart Blocks
- Occur when there is a delay in the conduction of
the impulse through the AV node - PR is gt 0.20 seconds
- SA node function is normal
57Heart Block Overview
- 1st degree
- PR interval gt 0.20 seconds
- All impulses reach the ventricles
- 2nd degree (2 types)
- Mobitz I each impulses takes longer to conduct
until 1 is blocked and a QRS complex is dropped
and a pause occurs then cycle repeats - Mobitz II Impulses are blocked at a regular
interval causing dropped QRS complexes - 3rd degree
- None of the atrial impulses reach the ventricles
- Activity of the atria and ventricles is
divorced - Results in inadequate cardiac output
- Requires pacemaker
581st degree
2nd degree Type 1
592nd degree Type II
3rd degree
60Pacemakers
61Ventricular pacemaker
Atrial Ventricular pacemaker
62Atrial Pacing
- A pacing electrode is placed in the right atrium
- Produces a pacemaker spike followed by a P wave
- May be used when the SA node is diseased or
damaged but conduction through the AV junction
and ventricles is normal
63Ventricular Pacing
- A pacing electrode is placed in the right
ventricle - Produces a pacemaker spike followed by a wide
QRS, resembling a ventricular ectopic beat
64Pacemakers
65Pacemaker Malfunction
- Loss of capture
- Undersensing
- Oversensing
- Loss of pacing
66Failure to Capture
- Recognized on the ECG by visible pacemaker spikes
not followed by P waves (if electrode in atrium)
or QRS complexes (if electrode in right ventricle)
67Failure to Sense (Undersensing)
- Recognized on the ECG by pacemaker spikes that
follow too closely behind the patients QRS
complexes
68(No Transcript)
69Activity Intolerance r/t Ineffective / decreased
myocardial function
Patient / Family Education Medication
regime Safety precautions
Fear r/t Unknown Deficient knowledge regarding
dysrhythmia Threat to health with fear of death
Dysrhythmia
Decreased cardiac output r/t Altered cardiac
rate / rhythm Dysfunctional electrical
conductivity or cardiac cells Ineffective /
decreased myocardial function
Deficient knowledge r/t New onset of disease Lack
of information of disease treatment
70Nursing Interventions
- Monitor and manage the dysrhythmia
- Minimize anxiety
- Teach self-care
71Evaluation
- Expected Patient Outcomes
- Maintains cardiac output
- Experiences reduced anxiety
- Expresses understanding of the dysrhythmia and
its treatment
72Case Study 9Coronary Artery Disease
- Assessment
- Telemetry
- Diagnosis
- Nursing diagnosis
- Collaborative problems / potential complications
- Planning and Goals
- Nursing Interventions
73NCLEX Questions
- The client show ventricular fibrillation on the
telemetry at the nurses station. Which action
should the telemetry nurse implement first? - Administer epinephrine IVP
- Prepare to defibrillate the client
- Call a STAT code
- Start cardiopulmonary resuscitation
74NCLEX Questions
- The client has chronic atrial fibrillation.
Which discharge teaching should the nurse discuss
with the client? - Instruct the client to use a soft-bristle
toothbrush - Discuss the importance of getting a monthly PTT
- Teach the client about signs of pacemaker
malfunction - Explain to the client the procedure for
synchronized cardioversion
75NCLEX Questions
- The client that is one day postoperative coronary
artery bypass surgery is exhibiting sinus
tachycardia. Which intervention should the nurse
implement? - Assess the apical heart rate for 1 full minute
- Notify the clients cardiac surgeon
- Prepare the client for synchronized cardioversion
- Determine if the client is having pain.
76References
- Aehlert, B. 1995). ECGs made easy. Mosby
Yearbook, Inc. St. Louis, MO. - Geiter, H.B. (2007). E-Z ECG Rhythm
Interpretation. F.A. Davis, Philadelphia. - LeMone, P., Burke, K. (2008). Nursing Care of
Clients with coronary heart disease. In
Medical-Surgical Nursing Critical Thinking in
Client Care, 4th Ed., pp. 957-1020. - Smeltzer, S.C., Bare, B.G. (2008). Management of
patients with dysrhythmias and conduction
problems. In Brunner Suddarths Textbook of
Medical Surgical Nursing, 11th ed. Pp.
822-857.