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ECG Interpretation, Pacemakers, and AICDs
KEY
SAN JOSE STATE UNIVERSITY
School of Nursing
Nursing 155
Learning Resources
1.
Elkin, M., Perry, A., & Potter, P. (2004). Nursing interventions and clinical skills (3rd ed. Pp. 403-407) St.
Louis, MO: Mosby.
2.
Jarvis, C. (2004). Physical examination and health assessment. (4th ed. pp. 490, 496). St. Louis, MO: Mosby.
3.
Lewis, S.M.., Heitkemper, M.M., & Dirksen, S.R. (2005). Medical-surgical nursing: Assessment and
management of clinical problems. (6th ed., pp. 861-878). St. Louis, MO: Mosby.
4.
Potter, P.A. & Perry; A.G. (2005). Fundamentals of nursing: Concepts, process, and practice (6th ed. pp. 644,
1069-1070). St. Louis, MO: Mosby.
5.
VT #148: Understanding pacemakers.
Independent Learning Activities
Learning Outcomes
1.
Identify five waveforms that comprise one heartbeat.
2.
Identify electrical and mechanical activity in the heart related to the waveforms.
3.
Determine the normal conduction pathway in the heart.
4.
Relate “depolarization” to mechanical activity in the heart.
5.
Determine time measurements on EKG graph paper.
6.
Systematically analyze a practice EKG strip.
7.
Distinguish among normal sinus rhythm, sinus tachycardia and sinus bradycardia.
8.
Identify the characteristics of normal sinus rhythm, sinus tachycardia, sinus bradycardia, sinus arrhythmia, and
atrial fibrillation.
9.
Define lethal arrhythmias.
10. Determine discharge teaching needs for a patient with an implanted pacemaker.
11. Differentiate between temporary and permanent pacemakers.
12. Identify three indications for mechanical pacing.
13. Describe the purpose and indications for A.I.C.D.
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Learning Activities
1. On the diagram, label each of the five waveforms that collectively represent one heartbeat.
R
T
P
Q
S
2. Each of the waveforms identified in Question #1 represent specific mechanical activity in the
heart. Identify the electrical and mechanical activity each waveform represents. The middle
three waveforms are generally grouped together as one complex.
Waveform
Electrical activity in the
heart
Mechanical activity in the
heart
P wave
Atrial depolarization
Atrial contraction
QRS complex
Ventricular depolarization
Ventricular contraction
T wave
Ventricular repolarization
Ventricular rest
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3. On the diagram, trace the normal conduction pathway in the heart. Label the approximate
locations of each of the following points on the pathway: Sino-atrial node, atrio-ventricular
node, bundle of His, bundle branches, Purkinje fibers.
Posteroinferior fasicle of left bundle
branch
Sino-atrial node
Purkinje
Atrio-ventricular node
Bundle of His
Right bundle branch
Purkinje
Left bundle branch
4. To say that “the atria have depolarized” is to describe an electrical activity of the heart. What
is the heart doing mechanically when this happens?
the atria are contracting
5. What is the mechanical activity of the heart during ventricular depolarization?
the ventricles are contracting
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The graph paper EKG strips are printed on are composed of small boxes within larger boxes. The
small boxes are 1 mm square. The larger boxes are composed of five 1mm boxes and are marked
by darker lines.
Time (in seconds) is recorded horizontally across the EKG strip.
1mm = ? sec.
sec.
5mm = ? sec.
6. How many seconds does a 1 mm box represent?
0.04 seconds
7. How many seconds does a 5 mm box represent?
0.20 seconds
8. How many large (5 mm) boxes represent one second?
5 boxes
9. How many large (5 mm) boxes represent 3 seconds?
15 boxes
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10. Use the following diagram to answer the questions and interpret the EKG strip.
QuickTi me™ and a
TIFF (LZW) decompressor
are needed to see this picture.
QuickTi me™ and a
TIFF (LZW) decompressor
are needed to see this picture.
a. What is the heart rate?
A simple way to do this is to count the number of R-waves in a six-second strip, then
multiply by 10. The EKG strip pictured is six seconds.
100/min
b. The rhythm is: regular
irregular
(circle one)
To determine if the rhythm is regular or irregular, use calipers to measure the distance
between two R-waves. Then see if that distance measurement is the same for all R-to-R
intervals. If it is, the rhythm is regular. If the distances are significantly different, the
rhythm is irregular.
c. Are P waves present or absent?
present
d. Is there a P wave for every QRS?
There should be only one P-wave in front of every QRS complex.
There is one P-wave for each QRS complex.
e. Measure the P-R interval. Is it normal?
The P-R interval is measured from the beginning of the P-wave to the beginning of the Qwave. Uses calipers to measure the number of small boxes contained within the P-R
interval, then convert that to seconds. Be sure to measure other P-R intervals in the strip
to make sure they are relatively consistent.
The P-R interval is 0.16 seconds
f. Measure the QRS complex. Is it normal?
The QRS interval is measured from the beginning of the Q-wave to the end of the Swave. Again, be sure to measure other QRS complexes in the strip to make sure they are
relatively consistent.
The QRS complex is 0.06 seconds
g. What is the rhythm? Sinus tachycardia
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11. What is the difference between the strip you just analyzed and sinus tachycardia and sinus
bradycardia?
a. Sinus tachycardia
sinus tachycardia has the same characteristics as normal sinus rhythm, except the rate is
faster than 100 beats/minute
b. Sinus bradycardia
sinus bradycardia has the same characteristics as normal sinus rhythm, except the rate is
slower than 60 beats/minute
12. Match the following heart rhythms to its proper description:
a.
normal sinus rhythm
(c) Regular rhythm, rate <60 beats/min, normal P wave, normal PR
interval, normal QRS complex
b.
sinus tachycardia
(e) Irregular rhythm, wavy baseline instead of P waves, normal QRS
complex
sinus bradycardia
(a Regular rhythm, rate 60-100 beats/min, normal P wave, normal PR
interval, normal QRS complex)
c.
d.
sinus arrhythmia
(d) Irregular rhythm, possibly related to respirations. Rate 60-100
beats/min, normal P wave, normal PR interval, normal QRS complex
(b) Regular rhythm, rate 100-180 beats/min, normal P wave, normal
PR interval, normal QRS complex
e.
atrial fibrillation
13. The following are lethal arrhythmias. Define each.
Ventricular
tachycardia
Ventricular rate 100-200 beats/min. On EKG, wide, bizarrelooking QRS complexes and T waves that deflect in the
opposite direction. P waves probably not visible. Patient may
be conscious or unconscious, cardiac output probably
inadequate. Death if rhythm untreated.
Ventricular
fibrillation
Ventricles fibrillating. No ventricular rate. On EKG, wavy
baseline with no P waves, no QRS complexes and no T-waves.
Death if rhythm untreated.
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14. Your patient has just had a pacemaker implanted and is about to be discharged. What will
you teach your patient in regarding the following areas: Provide a rationale for each.
a. Activity
Do not lift arm of surgical side above level of the heart for one week.
Rationale: This could dislodge pacemaker unit or wires. Goal is to allow tissue
around pacemaker to heal and seal unit in place.
b. Signs and symptoms that warrant a call to the physician’s office
If you experience the following signs and symptoms, notify your physician’s office:
redness or swelling at incision site, skin surrounding incision very warm and tender
to touch, purulent drainage.
Rationale: Infection may be present
15. What will you include in your long-term teaching?
-
Keep incision dry for one week after surgery
Avoid close proximity to high-output electrical generators or to large magnets
as an MRI scanner
Carry your pacemaker information card at all times.
such
It is very important to maintain all follow-up care with a physician for your
pacemaker function checks
16. What vital sign will you teach your patient to take on him/herself?
Pulse
17. List two types of temporary pacemakers and describe how they work.
Transcutaneous pacemaker: placed on the surface of the skin
Epicardial or venous pacemaker: threaded through a central vein
18. How is a permanent pacemaker different from this?
Internally placed, not painful (like transcutaneous), doesn’t limit activity (like epicardial
or transvenous)
19. Match the following conditions with the type of pacemaker that is appropriate to use for
each.
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B HR 40 in patient s/p cardiac surgery
a. transvenous pacemaker
C HR 35 in patient s/p syncopal episode,
presenting to the ER
b. epicardial pacemaker
c. transcutaneous pacemaker
A Patient who presented to the ER with a
HR in the 20’s and a transcutaneous
pacemaker was placed; current HR is
60
d. permanent pacemaker
D Patient with complete heart block, currently has a transvenous pacemaker keeping his
HR at 70
20. What is the advantage of temporary pacemakers?
Can be used quickly, such as in an emergency, and are not surgically implanted: they can be
easily removed when the client no longer needs pacing.
21. What is the purpose of an Automatic Implanted Cardiac Defibrillator (AICD)?
An AICD provides treatment for clients with life-threatening ventricular arrhythmias.
22. What are 3 indications for the use of an AICD?
Cardiac arrest survivors
Recurrent sustained ventricular tachycardia
Prophylaxis for clients at risk for sudden cardiac death