The
12 Lead ECG
in Acute Coronary Syndromes
Eric Lynn NREMT-P
Clinical Education Specialist
Amarillo Medical Services
Sponsored by:
12-Lead ECG in ACS Course
 Module I Essential Interpretation
 Module II Acquisition & Transmission
 Module III Acute Coronary Syndromes Part 1
 Module IV Acute Coronary Syndromes Part 2
 Module V The High Acuity Patient
 Module VI Bundle Branch Block & the ACS Imitators
MODULE 1
Essential 12-Lead
Interpretation
Essential 12-Lead ECG
Interpretation
 Goals
 Recognize and localize AMI on the 12-Lead
ECG
 Feel comfortable with 12-lead
interpretation
12-Lead ECG
12-Lead ECG
12-Lead ECG
12-Lead ECG
12-Lead ECG
12-lead ECG
12-Lead ECG
080.0
0.080
80 milliseconds = 0.08 seconds
12-Lead ECG
R Wave
Q Wave
S Wave
QRS
 Q waves
 Physiologic Q waves
 < .04 sec (40ms)
 Pathologic Q
 >.04 sec (40 ms)
QRS
 Q wave
QS Complex
J-Point
ST Segment
Practice
 Find J-points and ST segments
Practice
 Find J-points and ST segments
ST Segment
 Compare to TP segment
ST
TP
ST Segment Analysis
12-Lead ECG
 AMI recognition
 Two things to know
 What to look for
 Where you are looking
AMI Recognition
 What to look for
 ST segment elevation
 One millimeter or more (one small box)
 Present in two anatomically contiguous leads
ST Segment Elevation
 Presumptive evidence of AMI
 Indication for acute reperfusion
therapy
Practice
Lead “Views”
Lead Groups
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
Limb Leads
Chest Leads
Lead “Views”
Anatomical Position
Inferior Wall
 II, III, aVF
 Left Leg
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
Inferior Wall
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
Inferior Wall
Lateral Wall
 I and aVL
 Left Arm
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
Lateral Wall
 V5 and V6
 Left lateral chest
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
Lateral
 I, aVL, V5, V6
Lateral Wall
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
Anterior Wall
 V3, V4
 Left anterior chest
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
Anterior Wall
• V3, V4
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
Septal Wall
 V1, V2
 Along sternal borders
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
Septal
• V1,V2
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
AMI Localization
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
Anterior:
Septal:
Inferior:
Lateral:
V3, V4
V1, V2
II, III, AVF
I, AVL, V5, V6
AMI Recognition
I Lateral
aVR
II Inferior
aVL Lateral
III Inferior
aVF Inferior
V1 Septal
V4 Anterior
V2 Septal
V5 Lateral
V3 Anterior
V6 Lateral
AMI Recognition
 Know what to look for
 ST elevation
 > 1mm
 Two contiguous leads
 Know where you are looking
 Use pocket card as a reference
 You will soon have this memorized
Practice
Practice
Evolution of AMI
• Hyperacute
Evolution of AMI
• Acute
Evolution of AMI
• Acute
Evolution of AMI
• Age undetermined
AMI Recognition
A normal 12-lead ECG DOES NOT
rule out AMI
Practice
Practice
Practice
Reciprocal Changes
Reciprocal Changes
II, III, aVF
I, aVL, V leads
Practice
Practice
AMI Recognition
 Reciprocal changes
 Not necessary to presume infarction
 Strong confirming evidence when
present
AMI Recognition
AMI Recognition
 Imitators of infarct
 LVH
 BBB
 Ventricular beats
 Pericarditis
 Early Repolarization
 Others
Summary
 AMI recognition
 Know what you are looking for
 1mm of ST elevation
 Two contiguous leads
 Know where you are looking
 Positive electrode as an “eye”
 Pocket card
Summary
 Reciprocal changes
 Not necessary to presume infarction
 Strong confirming evidence when
present
Summary
 ST segment elevation is presumptive
evidence for AMI
 Other conditions may also cause ST elevation
Summary
A normal 12-Lead ECG DOES
NOT rule out AMI
ACS
AMI is part of a spectrum of
disease know as the
Acute Coronary Syndromes