Essential 12-Lead Essential 12-Lead

InterpretationInterpretation

MODULE 1MODULE 1

Essential 12-Lead ECG Essential 12-Lead ECG InterpretationInterpretation

• GoalsGoals

– Recognize and localize Recognize and localize AMI on the ECGAMI on the ECG

– Feel comfortable with Feel comfortable with 12-lead interpretation12-lead interpretation

12-Lead ECG12-Lead ECG

12-Lead ECG12-Lead ECG

12-Lead ECG12-Lead ECG

12-Lead ECG12-Lead ECG

12-lead ECG12-lead ECG

12-Lead ECG12-Lead ECG

80 milliseconds = 0.08 seconds

0.080 080.0

12-Lead ECG12-Lead ECG

R WaveR Wave

Q WaveQ Wave

S WaveS Wave

QRSQRS

• Q wavesQ waves

– Physiologic Q wavesPhysiologic Q waves

• < .04 sec (40ms)< .04 sec (40ms)

– Pathologic QPathologic Q

• >>.04 sec (40 ms).04 sec (40 ms)

QRSQRS

• Q waveQ wave

QS ComplexQS Complex

J-PointJ-Point

ST SegmentST Segment

PracticePractice

• Find J-points and ST segmentsFind J-points and ST segments

PracticePractice

• Find J-points and ST segmentsFind J-points and ST segments

ST SegmentST Segment

• Compare to TP segmentCompare to TP segment

ST TP

ST Segment AnalysisST Segment Analysis

12-Lead ECG12-Lead ECG

• AMI recognitionAMI recognition

– Two things to knowTwo things to know

• What to look forWhat to look for

• Where you are lookingWhere you are looking

AMI RecognitionAMI Recognition

• What to look forWhat to look for

– ST segment elevation ST segment elevation

• One millimeter or more (one One millimeter or more (one small box)small box)

• Present in two anatomically Present in two anatomically contiguous leadscontiguous leads

ST Segment ElevationST Segment Elevation

• Presumptive Presumptive evidence of AMIevidence of AMI

• Indication for acute Indication for acute reperfusion therapyreperfusion therapy

PracticePractice

Lead “Views”Lead “Views”

Limb Leads Chest Leads

I aVR V1 V4

II aVL V2 V5

III aVF V3 V6

Lead GroupsLead Groups

Lead “Views”Lead “Views”

Inferior WallInferior Wall

• II, III, aVFII, III, aVF

– Left LegLeft Leg

I

II

III

aVR

aVL

aVF

V1

V2

V3

V4

V5

V6

Inferior WallInferior Wall

Inferior Wall

I

II

III

aVR

aVL

aVF

V1

V2

V3

V4

V5

V6

Lateral WallLateral Wall

• I and aVLI and aVL

– Left ArmLeft Arm

I

II

III

aVR

aVL

aVF

V1

V2

V3

V4

V5

V6

Lateral WallLateral Wall

• V5 and V6V5 and V6

– Left lateral chestLeft lateral chest

I

II

III

aVR

aVL

aVF

V1

V2

V3

V4

V5

V6

LateralLateral

Lateral Wall

• I, aVL, V5, V6I, aVL, V5, V6

I

II

III

aVR

aVL

aVF

V1

V2

V3

V4

V5

V6

Anterior WallAnterior Wall

• V3, V4V3, V4

– Left anterior chestLeft anterior chest

I

II

III

aVR

aVL

aVF

V1

V2

V3

V4

V5

V6

Anterior WallAnterior Wall

• V3, V4V3, V4

I

II

III

aVR

aVL

aVF

V1

V2

V3

V4

V5

V6

Septal WallSeptal Wall

• V1, V2V1, V2

• Along sternal bordersAlong sternal borders

I

II

III

aVR

aVL

aVF

V1

V2

V3

V4

V5

V6

SeptalSeptal

• V1,V2V1,V2

I

II

III

aVR

aVL

aVF

V1

V2

V3

V4

V5

V6

AMI LocalizationAMI Localization

Anterior: Anterior: V3, V4V3, V4Septal: Septal: V1, V2V1, V2Inferior: Inferior: II, III, AVFII, III, AVFLateral:Lateral: I, AVL, V5, V6I, AVL, V5, V6

I

II

III

aVR

aVL

aVF

V1

V2

V3

V4

V5

V6

AMI RecognitionAMI Recognition

I Lateral

II Inferior

III Inferior

aVR

aVL Lateral

V1 Septal

aVF Inferior

V2 Septal

V3 Anterior

V4 Anterior

V5 Lateral

V6 Lateral

AMI RecognitionAMI Recognition

• Know what to look forKnow what to look for– ST elevationST elevation

– >> 1mm 1mm

– Two contiguous leadsTwo contiguous leads

• Know where you are lookingKnow where you are looking– Use pocket card as a referenceUse pocket card as a reference

– You will soon have this memorizedYou will soon have this memorized

PracticePractice

PracticePractice

Evolution of AMIEvolution of AMI

• HyperacuteHyperacute

Evolution of AMIEvolution of AMI

• AcuteAcute

Evolution of AMIEvolution of AMI

• AcuteAcute

Evolution of AMIEvolution of AMI

• Age undeterminedAge undetermined

AMI RecognitionAMI Recognition

A normal 12-lead ECG A normal 12-lead ECG

DOES NOTDOES NOT rule out AMI rule out AMI

PracticePractice

PracticePractice

PracticePractice

Reciprocal ChangesReciprocal Changes

Reciprocal ChangesReciprocal Changes

II, III, aVFII, III, aVF I, aVL, V leadsI, aVL, V leads

PracticePractice

PracticePractice

AMI RecognitionAMI Recognition

• Reciprocal changesReciprocal changes

– Not necessary to presume Not necessary to presume infarctioninfarction

– Strong confirming Strong confirming evidence when presentevidence when present

AMI RecognitionAMI Recognition

AMI RecognitionAMI Recognition

• Imitators of infarctImitators of infarct

– LVHLVH

– BBBBBB

– Ventricular beatsVentricular beats

– PericarditisPericarditis

– Early RepolarizationEarly Repolarization

– OthersOthers

SummarySummary

• AMI recognitionAMI recognition

– Know what you are looking forKnow what you are looking for

• 1mm of ST elevation1mm of ST elevation

• Two contiguous leadsTwo contiguous leads

– Know where you are lookingKnow where you are looking

• Positive electrode as an “eye”Positive electrode as an “eye”

• Pocket cardPocket card

SummarySummary

• Reciprocal changesReciprocal changes

– Not necessary to presume Not necessary to presume infarctioninfarction

– Strong confirming Strong confirming evidence when presentevidence when present

SummarySummary

• ST segment elevation is ST segment elevation is presumptive evidence for AMIpresumptive evidence for AMI

• Other conditions may also Other conditions may also cause ST elevationcause ST elevation

SummarySummary

A normal 12-Lead ECG A normal 12-Lead ECG

DOES NOTDOES NOT rule out AMI rule out AMI

ACSACS

AMI is part of a spectrum of

disease know as the

Acute Coronary SyndromesAcute Coronary Syndromes