Lake EMS Online Review: 12-Lead · PDF fileLake EMS Online Review: 12-Lead EKG ... American Heart Association Advanced Cardiovascular Life Support, ... AHA ACS Nomenclature 1

Lake EMS Online Review:12-Lead EKG

Created and prepared by: Captain Mike HilliardWith profound thanks and admiration to:

Henry J. L. (Barnie) Marriott, M.D., the father of 12-Lead ECGsTim Phalen, author of "12-Lead ECG: in AMI"Gary Denton, author of "Pre-Hospital 12-lead ECG"

This program is the Intellectual Property ofLake Emergency Medical ServicesUse of this program is limited to training and Quality Education only

Captain Mike Hilliard, Lake EMS Training Officer2761 West Old Highway 441, Mount Dora, FL 32757-3500

352/383-4554 (w); 352/735-4475 (f); [email protected]

Information also based on: American Heart Association Advanced

Cardiovascular Life Support, Professional © 2011

Recommendations for the Standardization and Interpretation of the Electrocardiogram: A Scientific Statement From the American Heart Association

Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society Endorsed by the International Society for Computerized Electrocardiology Parts I-VI

EKG paper review

Paper Speed • Most 12-lead EKG's follow a standard format

• This is called a 3x4 format, providing 2.5 seconds of each lead for your review

• The computer is looking at all 12 leads for a full 10 seconds

Calibration

• Paper speed, calibration, and frequency response are typically preset and do not require adjustment

Frequency Response

Lead Identity

One Complete Cardiac Cycle: For accurate EKG interpretation, 1 complete cardiac

cycle must be obtained in each lead Cardiac cycle equals a: P, QRS, and T-wave

Represents complete electrical cycle Hopefully corresponds to mechanical contraction

Patient Sex(now an important tool when assessing V2 & V3)

Patient Age

Patient Information

Measurements

Computerized Interpretive Statement

The Basics: 1 of 2 key points TP-segment:

Baseline from end of T-wave to beginning of P-wave; a more accurate baseline than PR-interval

T-P Segment Baseline

The Basics: 2 of 2 key points J-point:

Juncture angle between QRS and ST-segment

Then locate 0.04 sec. (1-small box) after the J-point

Compare the Two Measure J-point height verses TP-segment Difference of > 1-mm (1-small box) equals a

deviation A deviation in > 1 anatomically contiguous leads

equals problem

How to Measure ST-Segment Deviation

TP baseline

J-pointPlus 0.04 second

Find the:• TP line• J-point• One box to the right




Isoelectric


Isoelectric


Isoelectric


Isoelectric Depressed





Isoelectric ElevatedDepressed


The 3 "I"s1. Ischemia2. Injury3. Infarction

Ischemia Hallmark Primary hallmark:

ST-segment depression: > 0.5 mm Secondary signs:

Peaked T-waves Inverted T-waves

T-waves

Upright Inverted

It is normally upright (above baseline) in all leads except aVR and V1

T-waves

Upright Inverted

It is normally upright (above baseline) in all leads except aVR and V1

Injury Injury occurs if ischemia > 20-40 minutes Although cell death is threatened, if blood flow

can be restored we can avoid permanent myocardial death

STEMI is ST-segment elevation >2 contiguous leads or new LBBB

2010 (New) AHA STEMI guidelines Threshold values for STEMI are:

2010 (New) AHA STEMI guidelines Threshold values for STEMI are: 1 mm elevation in leads I, II, III, aVR, aVL,

aVF, V1, V4, V5, & V6 V2 and V3 have slightly altered parameters

as we will now demonstrate


aVF, V1, V4, V5, & V6 Women: 1.5 mm elevation in leads V2 & V3


aVF, V1, V4, V5, & V6 Women: 1.5 mm elevation in leads V2 & V3 Men >40: 2 mm elevation in leads V2 & V3


aVF, V1, V4, V5, & V6 Women: 1.5 mm elevation in leads V2 & V3 Men >40: 2 mm elevation in leads V2 & V3 Men <40: 2.5 mm elevation in leads V2 & V3



ACLS Manual Page 101

This is the rational for the importance of understanding and assessing the patient’s age and inputting their sex

Hallmark sign of Injury:

ST-segment elevation

Infarction Myocardial cell death; cells may demonstrate

injury and ischemia if area becomes larger Hallmark: Q-waves, >1 contiguous lead

Pathological: Q-waves > 1-mm wide and height > 25% of height of R-wave in same cardiac cycle

Physiological: Q-waves not indicative of above

Q-waves equate with myocardial death

Q-waves

Q-waves

Q-waveCorresponding R-wave

The Q-wave is 25% of the corresponding height of it’s R-wave

75%50%25%

See magical legend!

Q-wave

Q-waveCorresponding R-wave

The Q-wave is NOT 25% of the corresponding height of it’s R-wave

75%

50%

25%

See magical legend!

> 1 mm

Q-wave

> 1 mmPathological: Due to BOTH height AND width

Q-wave

< 1 mm

Q-wave

< 1 mm

Q-wave

Physiological: Due to lack of height and width

> 1 mm < 1 mm

Pathological Physiological

Q-wave

Fuzzy Logic Transition from ischemia, to injury, and ending in

infarction is actually a continuum modified by factors including: Extent of muscle involved O2 consumption O2 delivery And presence of collateral circulation

Consider the evolution of a burn with rings of varying degrees of damage

This is what we have to concentrate onThe acute portion of STEMI (Injury)

12-Lead Practice Assess for:

1. ST (1° sign suggestive for ischemia; depression >0.5 mm)

2. T-wave inversion (2° sign suggestive for ischemia)3. ST (suggestive of injury; elevation > 1.0 mm)4. Q-waves (suggestive of infarction)

12-Lead Practice Assess for:

1. Areas suggestive of ischemia2. Areas suggestive of injury3. Areas suggestive of infarction

EKG Practice

Practice Sample

EKG Practice

ST (1° sign suggestive for ischemia)

Practice Sample

ST Depression Leads I, aVL, V1, V2

EKG Practice

Practice Sample

T-wave inversion(2° sign suggestive for ischemia)

Practice Sample

EKG Practice

T Wave InversionFYI: aVR and V1 normally have T wave inversion

Practice Sample

EKG Practice

ST (suggestive of injury)

Practice Sample

EKG Practice

ST Elevation in Leads II, III, aVF

Practice Sample

EKG Practice

Practice Sample

Q-waves (suggestive of infarction)

EKG Practice

Are these pathological Q’s?

Practice Sample

EKG Practice

Nope! Pathological: Q-waves > 1-mm wide and height

> 25% of height of R-wave in same cardiac cycle Physiological: Q-waves not indicative of above

Electrode Placement

"Chest" Lead Placement Leads V1 - V6 are the chest/precordial leads.

The chest leads cannot be obtained without the limb lead wires attached: V1 - Right parasternally, 4th ICS V2 - Left parasternally, 4th ICS V3 - Between V2 and V4

V4 - 5th ICS, mid clavicular line V5 - Between V4 and V6

V6 - Left mid-axillary line, (level with V4)

• The leg lead wires can be placed on the torso above the indicated leg (left or right)

• But MUST stay below the level of the umbilicus

Localizing the 3 "I"s Ischemia: ST-segment depression Injury: ST-segment elevation Infarction: Q-waves > 1-mm wide and height >

25% of R-wave height However, deviation must be demonstrated in > 1

anatomically contiguous lead

LEADS LOOK AT:I, aVL, V5 and V6 Lateral wall of left ventricleII, III, aVF Inferior wall of left ventricleV1, V2 Septal wallV3, V4 Anterior wall of left ventricleV4R, V5R Right ventricle

I Lateral aVR V1 Septal V4 Anterior

II Inferior aVL Lateral V2 Septal V5 Lateral

III Inferior aVF Inferior V3 Anterior V6 Lateral

Anatomically Contiguous

AHA ACS Nomenclature1. STEMI:

ST elevation MI2. UA/NSTEMI:

High-risk unstable angina/non-ST-elevation MI3. Low/intermediate risk ACS

Normal or non-diagnostic changes in ST segment or T-wave

Where do we need to focus? Inferior, septal, anterior, lateral

1. Non-diagnostic: UA2. Suspicious for ischemia: NSTEMI3. Suspicious for injury: STEMI4. Suspicious for infarct: QWMI

EKG 1, 69 y/o male

Non-diagnostic (UA)

Suspicious for ischemia (NSTEMI): Inferior, Septal, Anterior, Lateral

Suspicious for injury (STEMI): Inferior, Septal, Anterior, Lateral

Suspicious for infarct (QWMI): Inferior, Septal, Anterior, Lateral

Non-diagnostic (UA)




EKG 1, 69 y/o male

Non-diagnostic (UA)




EKG 1, 69 y/o male

Non-diagnostic (UA)




EKG 1, 69 y/o male

Non-diagnostic (UA)




EKG 1, 69 y/o male

Non-diagnostic (UA)




EKG 2, 53 y/o male

Non-diagnostic (UA)




EKG 2, 53 y/o male

Non-diagnostic (UA)




EKG 2, 53 y/o male

Non-diagnostic (UA)




EKG 2, 53 y/o male

Non-diagnostic (UA)




EKG 2, 53 y/o male

Non-diagnostic (UA)




EKG 3, 58 y/o male

Non-diagnostic (UA)




EKG 3, 58 y/o male

Non-diagnostic (UA)




EKG 3, 58 y/o male

Non-diagnostic (UA)




EKG 3, 58 y/o male

Non-diagnostic (UA)




EKG 3, 58 y/o male

Non-diagnostic (UA)




EKG 4, 47 y/o male

Non-diagnostic (UA)




EKG 4, 47 y/o male

Non-diagnostic (UA)




EKG 4, 47 y/o male

Non-diagnostic (UA)




EKG 4, 47 y/o male

Non-diagnostic (UA)


Suspicious for injury (STEMI): Inferior, Septal (V2 well above 2 mm elevation),

Anterior (V3 well above 2 mm elevation), Lateral


EKG 4, 47 y/o male

Computerized InterpretiveStatement In existence for over 50 years Statistically accurate Not always correct Must always be viewed in light of the

surrounding clinical circumstances

Statistically accurate

Statistically accurateNot always correct

****Acute MI**** 52% sensitivity 98% specificity Acute MI = STEMI (ST Elevation MI)

When ACUTE MI statement is present, we should believe it

When ACUTE MI message is absent, do not rule out that either UA, NSTEMI, STEMI, or QWMI exists

Sensitivity Refers to recognition If the test always recognizes the disorder,

sensitivity would be 100% False negatives are failures of sensitivity A false negative occurs when condition exists

but the test fails to find it

Specificity Refers to the number of diagnoses confirmed If the diagnosis were corroborated every time

the test identifies it, it would be 100% specific False positives are failures in specificity A false positive occurs when the test indicates

the disease is present, when in fact it is not. I hate that when that happens!

12-Lead EKG Technology

If statement made, MI age undetermined, it is making claim of an old Physiological QWMI Pathological: Q-waves > 1-mm wide and height > 25%

of height of R-wave in same cardiac cycle

Diagnosis Sensitivity Specificity

Acute MI 52% 98%

RBBB 90-91% 100%

LBBB 78-87% 100%

LVH 32-76% 91-92%

WPW 92% 100%

When to perform 12-Lead? Chest Pain: Anginal or Atypical

Anginal: Fullness, pressure, crushing, may radiate to neck, jaw, back

Atypical: Unilateral, sharp, changes with position, pleuritic, muscular-skeletal, in jaw, neck, back ~15% of myocardial infarction patients describe atypical pain Females tend to experience atypical pain more often than

males

When to perform 12-Lead? Chest Pain: Anginal or Atypical

Anginal: Fullness, pressure, crushing, may radiate to neck, jaw, back

Atypical: Unilateral, sharp, changes with position, pleuritic, muscular-skeletal, in jaw, neck, back ~15% of myocardial infarction patients describe atypical pain Females tend to experience atypical pain more often than

males

Anginal Equivalents 40% of ACS patients will not experience pain

Note: 50% of patients with anginal pain are NOT having ACS event

Note: 40% of patients with ACS events will not have anginal pain

5 additional times toperform a 12-Lead

5 additional times toperform a 12-Lead1. Dyspnea (especially if associated with CHF)

5 additional times toperform a 12-Lead1. Dyspnea (especially if associated with CHF)2. Syncope, near syncope, and new onset

seizures


seizures3. Sweating disproportionate to the environment


seizures3. Sweating disproportionate to the environment4. Unexplained weakness, nausea or vomiting


seizures3. Sweating disproportionate to the environment4. Unexplained weakness, nausea or vomiting5. Palpitations/Dysrhythmias

2 Important points on STEMI The 12-Lead ECG is central to the initial risk and

treatment stratification Reports of elevated cardiac markers are not

necessary for a decision to administer fibrinolytic therapy or perform coronary intervention (angioplasty/stent)

Bundle Branch Block (BBB)

The effects of Intra-Ventricular Conduction Defects on the ECG

BBB Widens the QRS Deforms the QRS May Change

Repolarization The gross alteration of

depolarization (QRS widening) results in alteration of repolarization (ST-T changes)

BBB Widens the QRS Deforms the QRS May Change

Repolarization The gross alteration of

depolarization (QRS widening) results in alteration of repolarization (ST-T changes)

It’s kinda like a wolf in sheep’s clothing

BBB Turn Signal Theory Only works in V1

Only if QRS >0.12 Right BBB:

Which way do you push the turn signal indicator in the unit?

Left BBB: Which way do you push the

turn signal indicator in the unit?

• RBBB is identified by a wide QRS with the terminal portion of the QRS being positive in lead V1

• LBBB is identified by a wide QRS with the terminal portion of the QRS being negative in V1

BBB May Cause or Hide ST Elevation May Cause or Hide ST Depression May Change T Wave Polarity

This is particularly true in LBBB

Left Bundle Branch Block LBBB Bottom Line:

QRS in V1 > 0.12 seconds wide, and Terminal portion of QRS is negative

Is this a BBB?

EKG 5, 83 y/o male

Ayuh

EKG 5, 83 y/o male

Now, back to 12-LeadsOr 17-Leads as we might start calling them

Reciprocal Changes Inferior II, III, aVF » Anterior V1-V6, aVL, I Septal V1, V2 » Lateral V5, V6, I, aVL Early Anterior V1-V3 » Posterior V7-V9

When ST elevation is present, ST depression usually appears as well

ST depression typically shows up in opposing leads, AKA reciprocal depression

Special Considerations: RVI Right Ventricular Infarct (RVI):

If ST elevation in 2-contiguous inferior leads (II, III, aVF), obtain V4R

Right Ventricular Leads: V4R - 5th ICS, right mid-clavicular line

90% accurate for identifying RVI

Right Ventricular Infarct Results from Proximal RCA occlusion Accompanies Inferior Wall MI Can cause RVF and reduce LV filling pressure

Treatment for RVISigns of RVI Inferior Wall STEMI plus:

JVD Hypotension Dyspnea with clear lungs ST elevation in V4R AV blocks

Treatment for RVI Fluid for Hypotension NTG by slow drip MS in small careful doses

Non-diagnostic (UA)




Suspicious for BBB: LBBB, RBBB

Is a V4R assessment recommended?

EKG 6, 45 y/o male

Non-diagnostic (UA)






EKG 6, 45 y/o male

Non-diagnostic (UA)






EKG 6, 45 y/o male

Non-diagnostic (UA)






EKG 6, 45 y/o male

Non-diagnostic (UA)






EKG 6, 45 y/o male

Non-diagnostic (UA)






EKG 6, 45 y/o male

V4R

Non-diagnostic (UA)






EKG 6, 45 y/o male

V4R

Non-diagnostic (UA)





Is a V4R assessment recommended? RV STEMI

EKG 6, 45 y/o male

EKG 7, 50 y/o male

Non-diagnostic (UA)






Non-diagnostic (UA)






EKG 7, 50 y/o male

Non-diagnostic (UA)






EKG 7, 50 y/o male

Non-diagnostic (UA)






EKG 7, 50 y/o male

Non-diagnostic (UA)






EKG 7, 50 y/o male

Non-diagnostic (UA)






EKG 7, 50 y/o male

V4R

Non-diagnostic (UA)






EKG 7, 50 y/o male

Non-diagnostic (UA)





Is a V4R assessment recommended? No RV STEMI

V4R

EKG 7, 50 y/o male

Special Considerations:Posterior Posterior Left Ventricular Infarct:

If ST depression in 2-contiguous early V leads (V1-V3), obtain V7-V9

Posterior leads: V7 - Post axillary line, level with V4

V8 - Mid scapular line, level with V4

V9 - Left paravetebral area, level with V4

What do you see?EKG 8, 92 y/o male

What do you see?EKG 8, 92 y/o male

V2 & V3 depressionEKG 8, 92 y/o male

V2 & V3 depressionequals need to assess posterior

EKG 8, 92 y/o male

Elevation in V7, V8, V9

EKG 8, 92 y/o male

Elevation in V7, V8, V9equals Posterior STEMI

EKG 8, 92 y/o male

And 7 Reasons why we perform serial 12-Leads

Well done Adrian Whicker

Reason number 1This is a 49 y/o woman

7-minutes later

10-minutes later(Adrian has asked his driver to drive without due regard for safety)

16-minutes later(Adrian has told his driver to push over, he's driving now)

23-minutes laterA 15-box elevation!

25-minutes later; What does the notching indicate?

This is what we have to concentrate onThe acute portion of STEMI (Injury)

30-minutes later

Cereal 12-Lead EKGs Assessing a patient's rhythm is a dynamic

process, that is why we monitor the patient's rhythm consistently

When a patient has had their 12-Lead assessed, leave the electrodes and precordial leads in place and reassess during every change in: Discomfort, rhythm, or vital signs

And in Conclusion… What's going on in this last slide? Is there ischemia? Is there injury? Do we need a right sided assessment? Do we need a posterior assessment?

Non-diagnostic (UA)





Is a right sided assessment recommended?

Is a posterior assessment recommended?

EKG 9, 57 y/o male

Non-diagnostic (UA)







EKG 9, 57 y/o male

Non-diagnostic (UA)







EKG 9, 57 y/o male

Non-diagnostic (UA)







EKG 9, 57 y/o male

Non-diagnostic (UA)







EKG 9, 57 y/o male

AHA ACS Nomenclature1. STEMI:

ST elevation MI2. UA/NSTEMI:

High-risk unstable angina/non-ST-elevation MI3. Low/intermediate risk ACS

Normal or non-diagnostic changes in ST segment or T-wave

KeyEKG NSTEMI STEMI Special1 Inferior Lateral2 Septal, lateral Inferior3 Lateral Inferior4 Inferior Septal, anterior, lateral5 BBB BBB BBB6 Septal, anterior, lateral Inferior RVI7 Septal, anterior Inferior No RVI8 Anterior Inferior. Lateral BBB stops

Posterior Dx9 Inferior, lateral Septal

Ischemia Hallmark Primary hallmark:

ST-segment depression: > 0.5 mm Secondary signs:

Peaked T-waves Inverted T-waves



LEADS LOOK AT:I, aVL, V5 and V6 Lateral wall of left ventricleII, III, aVF Inferior wall of left ventricleV1, V2 Septal wallV3, V4 Anterior wall of left ventricleV4R, V5R Right ventricle

I Lateral aVR V1 Septal V4 Anterior

II Inferior aVL Lateral V2 Septal V5 Lateral

III Inferior aVF Inferior V3 Anterior V6 Lateral

Anatomically Contiguous

Special Considerations: RVI Right Ventricular Infarct (RVI):

If ST elevation in 2-contiguous inferior leads (II, III, aVF), obtain V4R

Right Ventricular Leads: V4R - 5th ICS, right mid-clavicular line

90% accurate for identifying RVI

Special Considerations:Posterior Posterior Left Ventricular Infarct:

If ST depression in 2-contiguous early V leads (V1-V3), obtain V7-V9

Posterior leads: V7 - Post axillary line, level with V4

V8 - Mid scapular line, level with V4

V9 - Left paravetebral area, level with V4

Lake EMS Online Review:12-Lead EKG

Created and prepared by: Captain Mike HilliardWith profound thanks and admiration to:

Henry J. L. (Barnie) Marriott, M.D., the father of 12-Lead ECGsTim Phalen, author of "12-Lead ECG: in AMI"Gary Denton, author of "Pre-Hospital 12-lead ECG"

This program is the Intellectual Property ofLake Emergency Medical ServicesUse of this program is limited to training and Quality Education only

Captain Mike Hilliard, Lake EMS Training Officer2761 West Old Highway 441, Mount Dora, FL 32757-3500

352/383-4554 (w); 352/735-4475 (f); [email protected]

Documents

Lake EMS Online Review: 12-Lead · PDF fileLake EMS Online Review: 12-Lead EKG ... American Heart Association Advanced Cardiovascular Life Support, ... AHA ACS Nomenclature 1