Session Number 403
12 LEAD ECG WORKSHOP
Linda Bucher, RN, PhD, CEN, CNE
Staff Nurse
Virtua Memorial Hospital – Emergency Department
Mt. Holly, NJ
Content Description
This presentation will provide a basic introduction to 12 lead ECG interpretation. Emphasis will
be on normal 12 lead patterns and patterns of myocardial ischemia, injury, and infarction. Small
group work will allow participants to apply information to case studies.
Learning Objectives
At the end of this session and small group work, the participant will be able to:
1. Interpret a normal 12-lead ECG.
2. Differentiate patterns of ischemia, injury, and infarction as seen on 12-lead ECGs.
3. Apply information to the analysis of 12-lead ECG case studies.
Summary of Key Points/Outline
I.
II.
III.
IV.
V.
VI.
VII.
Issues related accurate 12 lead ECGs
A. Patient preparation for 12 lead ECG
B. Proper lead placement
Polarity of leads
Patterns of leads
A. I, aVL
B. II, III, aVF
C. V1-6
PQRST morphology across 12 leads
Patterns of Ischemia
A. ST segment changes
B. T wave changes
Patterns of Injury
A. ST segment changes
B. T wave changes
Patterns of Infarction
A. ST segment changes
B. T wave changes
C. Q waves
VIII.
IX.
X.
Reciprocal changes
Relationship of patterns of ECG changes to coronary arteries and other cardiac structures
Case Study Analyses
Bibliography/Webliography
1. Jacobsen, C. (2008). ECG diagnosis of acute coronary syndrome. AACN Advanced Critical
Care, 19(1), 101–108.
2. O’Gara PT, Kushner FG, Ascheim DD, et al. (2013). 2013 ACCF/AHA guideline for the
management of ST-elevation myocardial infarction: A report of the American College of
Cardiology Foundation/American Heart Association Task Force on Practice Guidelines, Journal
of the American College of Cardiology, 61(4), e78-e140. doi:10.1016/j.jacc.2012.11.019
3. Sheehan, T., & Gray, T. 12 lead EKG boot camp series: Using case studies to interpret
ischemia, injury and infarction. Retrieved from
www.aacn.org/DM/CETests/Overview.aspx?TestID=726&mid=2864&ItemID=718
4. Wesley, K. (2011). Huszar’s basic dysrhythmias and acute coronary syndromes (4th ed.). St.
Louis, MO: Elsevier.
Speaker Contact Information
lbucher@udel.edu
12 lead ECG Workshop
Presented by
Linda Bucher, PhD, RN, CEN, CNE
•Interpret a normal 1212-lead ECG.
•Differentiate patterns of ischemia, injury,
and infarction.
•Apply information to analysis of 1212-lead ECG
case studies.
“the patient needs a 1212-lead”
lead”
 Improving the accuracy of
the 1212-Lead ECG
– Patient preparation
»Positioning
– Skin preparation
»Gauze
»Alcohol
Improving the accuracy of a
1212-lead ECG: Lead Placement

Four limb leads
– Left arm
– Left leg
– Right arm
– Right leg (ground)
Improving the accuracy of a
1212-lead ECG
Improving the accuracy of a
1212-lead ECG
 Dealing with lead placement
 Dealing with ECG tracing
“challenges”
challenges”
– Hair: shave v. clip?
– Diaphoresis
– Anatomy
 Implications of incorrect lead
placement
“challenges”
challenges”
– Internal factors (patient)
– External factors (environment)
What do those 12 leads look like?
like?
 Frontal Plane
– Bipolar (+ and -) limb leads
»Lead I
»Lead II
»Lead III
RA
LA
RA
LA
LL
LL
What do those 12 leads look like?
like?
RA
LA
RA
LA
 Frontal Plane
LL
LL
– Augmented (a) limb leads
(unipolar: +)
»aVR
»aVL
»aVF
RA
What do those 12 leads look like?
like?
LA
 Horizontal plane (unipolar: +)
– V1
– V2
– V3
– V4
– V5
– V6
LFoot
R
+
+
q
+
+
+
+
+
+
r
S
Normal R wave progression
What are those 12 leads looking at?
at?
 Inf
Inferior wall of left ventricle
LA
RA
Normal R wave
progression
LL
LL
LEFT FOOT
What are those 12 leads looking at?
at?
 Lateral wall of left ventricle (high)
RA
LA
LA
What are those 12 leads looking at?
at?
 Ventricular septal wall
– V1 and V2
 Anterior wall of left ventricle
–(V2), V3, and V4
 Lateral wall of left ventricle (low)
– V5 and V6
21
So … moving beyond the basics
 Linking patterns of leads, coronary
arteries, areas of the myocardium,
and other (not so obvious) cardiac
structures
 Differentiating patterns of ischemia,
injury, and infarction
Patterns of Ischemia,
Ischemia, Injury,
Infarction
 Ischemia
– ST segment depression
– T wave inversion
62 y.o. male presents with “chest tightness.”
tightness.”
Initial ECG
After treatment…
treatment…
Patterns of Ischemia, Injury,
Injury,
Infarction
 Injury: ST segment elevation
Patterns of Ischemia, Injury,
Infarction
 Infarction: Hyperacute
stage
Patterns of Ischemia, Injury,
Infarction
 Acute Infarction
– ST segment elevation
– T wave inversion
– Reciprocal changes
»V1 through V6, I, and aVL
II, III, aVF
»II, III, aVF
Patterns of Ischemia, Injury,
Infarction
 Acute Infarction
– Development of a pathologic
Q wave (wide, >25% of height
of R wave)
I, aVL, V5, V6
Patterns of Ischemia, Injury,
Infarction
 Resolution of Acute Infarction
– ST segment returns to baseline
– T wave usually resumes
upright position
– Pathologic Q wave persists for
life
Normal 12 lead #1
ECG #1
ECG #2
ECG #3
ECG #4
ECG #5
1
12 LEAD ECG WORKSHOP
Linda Bucher, RN, PhD, CEN, CNE
Staff Nurse
Virtua Memorial Hospital – Emergency Department
Mt. Holly, NJ
Case Study: ECG #1
The patient is a 48 yo male firefighter who presented to the ED with intermittent, midsternal,
chest pain that developed today while fighting a fire. He puts on the call light and tells you “I’m
having that pain again.”
Review the 12 Lead ECG and complete the following information:
1. Basic (underlying) Rate and Rhythm:
2. R wave progression: Normal or Abnormal
If abnormal, describe:
3. Pathologic Q waves present?
Yes
No
If yes, identify leads:
4. ST segments (circle all that apply):
Isoelectric
Depressed
Elevated
If depressed, identify leads:
If elevated, identify leads:
5. T waves: Normal or Abnormal
If abnormal, identify leads and describe:
6. Reciprocal changes present?
Yes
No
If yes, identify leads:
7. Interpretation:
Think about the coronary arteries involved; treatment strategies, including monitoring;
and possible complications that would apply to this patient.
2
Case Study: ECG #2
The patient is a 52 yo black female who presents with left arm pain and SOB. PMH: IDDM,
HTN. She was brought to the ED by a coworker when these symptoms developed at lunch.
Patient tells you that the pain started on her way to work that morning.
Review the 12 Lead ECG and complete the following information:
1. Basic (underlying) Rate and Rhythm:
2. R wave progression: Normal or Abnormal
If abnormal, describe:
3. Pathologic Q waves present?
Yes
No
If yes, identify leads:
4. ST segments (circle all that apply):
Isoelectric
Depressed
Elevated
If depressed, identify leads:
If elevated, identify leads:
5. T waves: Normal or Abnormal
If abnormal, identify leads and describe:
6. Reciprocal changes present?
Yes
No
If yes, identify leads:
7. Interpretation:
Think about the coronary arteries involved; treatment strategies, including monitoring;
and possible complications that would apply to this patient.
3
Case Study: ECG #3
The patient is an 80 yo female who was admitted from the nursing home because of new onset
confusion and agitation. Patient is normally oriented to person and place. Patient is unable to tell
you if she has chest pain. B/P: 96/50 (baseline: 136/70), RR: 26 (baseline: 18), T: 98.8, Pulse Ox:
91% (RA), peripheral pulses are weak. The patient’s daughter is in route to the hospital.
Review the 12 Lead ECG and complete the following information:
1. Basic (underlying) Rate and Rhythm:
2. R wave progression: Normal or Abnormal
If abnormal, describe:
3. Pathologic Q waves present?
Yes
No
If yes, identify leads:
4. ST segments (circle all that apply):
Isoelectric
Depressed
Elevated
If depressed, identify leads:
If elevated, identify leads:
5. T waves: Normal or Abnormal
If abnormal, identify leads and describe:
6. Reciprocal changes present?
Yes
No
If yes, identify leads:
7. Interpretation:
Think about the coronary arteries involved; treatment strategies, including monitoring;
and possible complications that would apply to this patient.
4
Case Study: ECG #4
A 65 yo male presents with a history of intermittent substernal chest pain over the past 4-5 d. He
states he saw his PCP today and was sent to the hospital with his ECG. He denies pain at this
time. PMH: hyperlipidemia, BMI>30, prostate cancer (in remission).
Review the 12 Lead ECG and complete the following information:
1. Basic (underlying) Rate and Rhythm:
2. R wave progression: Normal or Abnormal
If abnormal, describe:
3. Pathologic Q waves present?
Yes
No
If yes, identify leads:
4. ST segments (circle all that apply):
Isoelectric
Depressed
Elevated
If depressed, identify leads:
If elevated, identify leads:
5. T waves: Normal or Abnormal
If abnormal, identify leads and describe:
6. Reciprocal changes present?
Yes
No
If yes, identify leads:
7. Interpretation:
Think about the coronary arteries involved; treatment strategies, including monitoring;
and possible complications that would apply to this patient.
5
Case Study: ECG #5
The patient is a 58 yo Hispanic male who presents to the ED with substernal chest pain that he
rates 12/10. He states that the pain started approximately 2 hours ago while at work. Patient is
diaphoretic, gray, and clutching his chest. VS: B/P: 118/60, RR: 22, T: 98.9, Pulse Ox: 95%
(RA).
Review the 12 Lead ECG and complete the following information:
1. Basic (underlying) Rate and Rhythm:
2. R wave progression: Normal or Abnormal
If abnormal, describe:
3. Pathologic Q waves present?
Yes
No
If yes, identify leads:
4. ST segments (circle all that apply):
Isoelectric
Depressed
Elevated
If depressed, identify leads:
If elevated, identify leads:
5. T waves: Normal or Abnormal
If abnormal, identify leads and describe:
6. Reciprocal changes present?
Yes
No
If yes, identify leads:
7. Interpretation:
Think about the coronary arteries involved; treatment strategies, including monitoring;
and possible complications that would apply to this patient.