Remove the Mystery from 12 Lead EKG Interpretation for Acute MI The simple, rapid 12 lead solution to 12 lead confusion! A 12 Lead Program for ALL health.

Remove the Mystery from

12 Lead EKG Interpretation for Acute MI

The simple, rapid “12 lead solution” to 12 lead confusion!

A 12 Lead Program for ALL health care professionals!

Copyright Apex Innovations 2003

The Basics…..Let’s do the re-view

Coronary Anatomy

Conduction

Paper and rate basics

Rhythm

Lead placement

Vectors and axis

R wave progression

Coronary Anatomy

Right CoronaryArtery (RCA)

Aorta

Circumflex (Cx)

Left AnteriorDecending (LAD)

Conduction:

Normal P-QRS-T Constant, Continuous Conduction….the beat goes

onP wave

Depolarization & contraction of

both atria

QRS..

Ventricular

depolarization

T wave…

Ventricular

repolarization

Iso-electric Line

Conduction:

Normal P-QRS-T Constant, Continuous Conduction….the beat goes

on

Q-First down slope

R-Upward slope

S-Down slope

Iso-electric Line

Normal P-QRS-T

P Wave PR Interval QRS Complex ST Segment

Represents Atrial depolarization

Time between onset of atrial depolarization and onset of ventricular depolarization (AV conduction time)

Ventricular depolarization

Interval between ventricular

depolarization and repolarization

Duration < 0.12 seconds

0.12 - 0.20 seconds 0.04 - 0.10 seconds Measure from end of QRS to J-point, the

beginning of T wave

Height < 2.5 mm Measure start of P wave to start of QRS

Q- First negative deflection R- First positive deflectionS- Negative deflection after R wave

Shape Smooth Prolonged indicates a conduction block

Shortened indicates accelerated conduction or junctional in origin

In relation to iso-electric line:Depression/

Negative indicates ischemia

Elevation/Positive indicates injury

Orientation Positive in Leads I,II,aVF,

V4Negative in

aVR

Cardiac Conduction System

LeftBundleBranch

Purkinjefibers

RightBundle Branch

Bundle of His

AV node

Internodalpathways

Sinus node

Cardiac Conduction System

Relationship of ECG to anatomy

One Small Block = .04 Seconds

Standard paper speed = 25mm per secondNote calibration on side of EKG - 2 Large

Blocks tall

One Large Block = .20 Seconds

-Increased paper speed makes complexes wider-Decreased paper speed makes the complexes

narrower

Rate: EKG Paper Basics

One small Block = 1mm Voltage

One Large Block = 5mm Voltage

Rate: Calculation Options

1. RATE = # of R waves in a 6 second strip X 10

2. RATE = 300 # large squares between R waves

3. RATE Count = Count from a QRS complex on any bold line to the next QRS complex. Count “300, 150, 100, 75, 60, 50” for each bold line after first complex.

300 150 100 75 60 50

Start End

Rate = 82 BPM

Rhythms

• Normal Sinus

• Sinus Bradycardia

• Sinus Tachycardia

• Sinus Arrhythmia

• Sick Sinus Syndrome

• Wandering Atrial Pacemaker

• Sinus Block

• Sinus Arrest

Sinus (SA Node)

Rhythms Continued

• Premature Atrial Contraction (PAC)

• Paroxysmal Atrial Tachycardia (PAT)

• Multifocal Atrial Tachycardia

• Atrial Flutter

• Atrial Fibrillation

Atrial Rhythms

Rhythms Continued

• Premature Junctional Contraction (PJC)

• Paroxysmal Junctional Tachycardia (PJT)

• Junctional Flutter

• Junctional Fibrillation

Junctional (AV)

Rhythms Continued

• Premature Ventricular Contraction (PVC)

- Bigeminy Trigeminy, Quadrageminy

• Paroxysmal Ventricular Tachycardia (PVT)

• Multifocal Ventricular Tachycardia

• Ventricular Flutter

• Ventricular Fibrillation

Ventricular

Rhythms Continued

• 1 Prolonged PRI

• 2 Type I - Wenchebach

• 2 Type II - Mobitz II

- 2:1, 3:1 Conduction

• 3 Complete Heart Block

• Bundle Branch

- Right BB

- Left BB

AV Blocks

The 12 Lead EKG…

6 Limb Leads 6 Chest or Pre-cordial Leads

IIIIII

AVRAVLAVF

V1V2V3

V4V5V6

12 angles or pictures

of the electrical activity of the heart

Looking and Learning: Vectors and Axis ~the hard way~

A panoramic view

of the heart’s

electrical activity from

12 different angles

The sum of all vectors determines the axis

Lead Placement - Lead I, II, III

RA LA

LL

+-LEAD I Bipolar Limb Lead• Looks from Right to Left Shoulder

• Looks at high lateral wall of

left ventricle

• Supplied by circumflex artery–CX

• Positive/upright P QRS T


RA LA

LL

+-

LEAD II Bipolar Limb Lead• Looks from R Shoulder to Left Leg• Looks at inferior wall of left ventricle

• Supplied by right coronary artery–RCA

• Positive/upright P QRS T

+

-


RA LA

LL

+-

+

-

LEAD III Bipolar Limb Lead• Looks from Left Shoulder to Left Leg• Looks at inferior wall of left ventricle • Supplied by right coronary artery-RCA• A biphasic QRS complex is expected

-

+

Augmented Limb Leads

LA RA

LL

+ +

+

AVR Augmented Voltage Right Arm • All complex waves are negative• Typically, this lead not used for diagnosing!

AVL Augmented Voltage Left Arm • Looks at lateral wall of left ventricle • Supplied by circumflex artery - CX• All complexes should be positive

AVF Augmented Voltage (left) Foot • Cross between Leads I and II • Looks at inferior wall of left ventricle • Supplied by right coronary artery-RCA• All complexes should be positive

Lead Placement – V-Leads

V1-V2 = Septal

V3-V4 = Anterior

V5-V6 = Lateral

V1-V3 = Posterior

V1 – 4th ICS, right of sternum

V2 – 4th ICS, left of sternum

V3 – Midpoint between V2 and V4

V4 – 5th ICS, mid-clavicular line

V5 – Level with V4 , anterior to axillary line

V6 – Level with V4, mid-axillary line

V-Lead R Wave Progression

- V1 - R wave is generally smallest or most negative

- V4 - R wave is typically the tallest or most positive

- Lack of R wave progression may mean :

Pathology- Disease state, CAD, Septal wall MI

Normal- A patient with Congenital state, Rotated heart, Obesity, COPD

Other- Breast tissue, poor lead placement

The progression or increasing in R wave amplitude from

negative to positive in leads V1 to V4 is expected and

normal!

R Wave Progression in the V Leads

V1 – PQRST All negative

V2 – PQRST Should be mostly negative but

start progression

V3 – PQRST Biphasic with upright T waves

V4 – PQRST Nearly completely upright

V5 – PQRST Upright

V6 – PQRST Upright

Myocardial Infarction

Ischemia

Injury

Recognition

Criteria

Infarct Location Template

AMI Evolution

Practice EKG’s

Bumps, elevations and tombstones…

Myocardial Infarction

Occurs when a coronary artery is narrowed and occludes, terminating the blood and oxygen supply. This results in

cardiac hypoxia and irritability which may cause fatal arrhythmias. Without a blood supply to the cardiac muscle, depolarization cannot happen and renders the muscle, electrically dead.

An EKG can diagnose AMI location, identify the culprit artery and reveal any blocks in

ventricular conduction.

ST Depression = Ischemia

• Inverted T waves, sometimes peaked

• T wave deflection is opposite from QRS (Normally T wave is upright when QRS is upright and vice versa)

• T wave inversion is usually in same leads that demonstrates signs of acute infarction

(Q waves, ST elevation)

Causes for ST depression

• Ischemia• Digoxin Toxicity• Pulmonary Embolism• Ventricular Hypertrophy• Left Bundle Branch

Block

ST Elevation = Current Injury

• Depicts current myocardial injury

• Measure J-point to beginning of ventricular repolarization

• May be elevated >1mm in limb leads and >2mm in precordial leads

• Will see reciprocal ST depression in other leads

Causes for ST elevation

• Pericarditis• Ventricular aneurysm• Drug induced• Myocardial Infarction

Recognition of AMI

• Know what to look for:– ST elevation >1 mm– 3 contiguous leads

PR baseline

ST-segment deviation= 4.5 mm

J point

AMI Requires at least 2 of these criteria:

1. History of characteristic chest pain Crushing-pressure in chest, pain

radiation to jaw, arms, back, N/V, SOB, diaphoresis

2. Evolutionary EKG changes ST depression (ischemia) ST elevation (injury) Q wave development (muscle

death)3. Elevated cardiac enzymes Troponin, CKMB-CK, Myoglobin

Understanding infarct location

Here’s the trick!

The 12 Lead Solution

to

12 Lead Confusion!

Simple - Rapid!!

Finally…….

Remove the mystery!Location, Location,

Location!

AMI Location Correlation

aVF InferiorIII Inferior V3 Anterior V6 Lateral

aVL LateralII Inferior V2 Septal V5 Lateral

aVRI Lateral V1 Septal V4 Anterior

Lateral Lead ST Elevation in AMI

LEAD I AVL V5 V6

Lateral: Usually supplied by Circumflex (CX)Look for reciprocal changes in Lead V1

“High Lateral” Wall

Normal EKG

Lateral

Lateral Lateral

Lateral

ReciprocalChange

Inferior Lead ST Elevation in AMI

LEAD II AVFLEAD III

Inferior: Usually supplied by Right Coronary Artery (RCA)Look for reciprocal changes in Leads I, AVL

Normal EKG

Inferior

Inferior

Inferior

Reciprocal Change

Reciprocal Change

Septal Lead ST Elevation in AMI

V1 V2

Septal: Usually supplied by Left Anterior Descending (LAD)Look for reciprocal changes in Leads V3, AVF

Normal EKG

Septal

Septal

Reciprocal Change

Reciprocal Change

Anterior Lead ST Elevation in AMI

V3 V4

Usually supplied by Left Anterior Descending (LAD)Look for reciprocal changes in Leads V2, AVF

Normal EKG

Anterior

Anterior

Reciprocal Change

Reciprocal Change

12 Lead-Paper Heart

To better understand rhythm location:

1. Hold left upper corner and right lower corner of EKG2. Roll EKG to note: inferior leads at apex lateral leads on sides anterior and septal leads in front

• Height is 1/3 the size of entire QRS complex• Width is at least one square or 0.04 seconds in duration • Q waves in V1,V2,V3 or V4 indicate anterior or anteroseptal infarction• Damage from old infarcts cause Q waves that last a lifetime • Abnormal if thick on tracing• Q wave may be normal in AVR

Significant Q Wave Characteristics

ST segment Evolution and Q wave development with AMI

A

Differentiating Between Acute and Old MI

• Q wave with no other morphology = old MI

• Q wave and ST segment elevation (with or without T wave inversion) = AMI

• Q wave and inverted T wave = age undetermined

Evolutional Changes of an Acute Myocardial Infarction

Identify infarct location using a systematic

approach Rhythm

ST Depression

ST Elevation

R Wave Progression

Q Waves

Let’s take a look at…

the Good, the Bad and

the Ugly!

~EKG Review~

Review #1 What Does This 12-Lead ECG Show?

LATERAL SEPTAL ANTERIOR

INFERIOR LATERAL SEPTAL LATERAL

INFERIOR INFERIOR ANTERIOR LATERAL

INFERIOR

INFERIOR INFERIOR





LATERAL ANTERIOR

LATERAL LATERAL

ANTERIOR LATERAL





LATERAL ANTERIOR

LATERAL LATERAL

ANTERIOR LATERAL

Appearances and History are Important!

Your patient, a 58 y/o male, was diagnosed with cancer 2 weeks ago and was scheduled to receive his first chemotherapy treatment this morning. Instead, he was delivered in a wheelchair hurriedly (by his oncologist), to the emergency department in distress. He presents complaining of intense chest pain described as a “10”, is very restless, nauseated, diaphoretic and pale. You order the usual cardiac work-up. Here is what his EKG showed…





Later that day…

This patient’s cardiac workup returned within normal limits and was

diagnosed with anxiety and released to begin his chemotherapy.





LATERAL ANTERIOR

LATERAL LATERAL

ANTERIOR LATERAL





INFERIOR LATERAL

INFERIOR INFERIOR LATERAL





LATERAL ANTERIOR

LATERAL LATERAL

ANTERIOR LATERAL

Appearances and History are Important!

Your patient, a 62 year old male pharmacist, presents at 6:00AM with chest pressure radiating to his neck, jaw and left arm. He is mildly short of breath and says he’s had indigestion all night. You order the usual cardiac work-up. Here is what his EKG showed…

Review #8 What Does This 12-Lead ECG

Show?





LATERAL SEPTAL LATERAL

ANTERIOR LATERAL

Later that day…

The Inferolateral/Anteroseptal MI

caused massive injury and tissue death,

and the patient subsequently died.





INFERIOR

INFERIOR INFERIOR





SEPTAL

SEPTAL

Posterior MI’s can be tricky!

EKG changes are seen in V1-V3 (the anterior precordial leads)

and are a mirror image of an anteroseptal MI

Posterior MI HINT: R waves in V1 and V2?Suspect Posterior MI!

You will see:Increased R wave amplitude and duration

R wave is more prominent than S wave in V1 and V2ST depression and large inverted T waves V1-V3


LATERAL SEPTAL? ANTERIOR

INFERIOR LATERAL SEPTAL? LATERAL

INFERIOR INFERIOR ANTERIOR? LATERAL

POSTERIOR

POSTERIOR

POSTERIOR

LATERAL SEPTAL? ANTERIOR

INFERIOR LATERAL SEPTAL? LATERAL

INFERIOR INFERIOR ANTERIOR? LATERAL

POSTERIOR

INFERIOR POSTERIOR

INFERIOR INFERIOR POSTERIOR

Review #12 What Does This 12-Lead ECG Show? Look at those R waves!!!

~~ Time is Muscle! ~~

Tick-Tock

~Test Time~

Please stop here!1.Answer the Self Assessment

Sheet’s

first 8 questions.

2. Next proceed to the remaining

slides and record the infarct location

for each EKG on the self assessment.

Quiz #1 Where is the elevation or infarct?




INFERIOR

INFERIOR INFERIOR





SEPTAL ANTERIOR

SEPTAL

ANTERIOR





LATERAL

LATERAL LATERAL

LATERAL




SEPTAL ANTERIOR

SEPTAL

ANTERIOR






LATERAL ANTERIOR

LATERAL LATERAL

ANTERIOR LATERAL





SEPTAL ANTERIOR

SEPTAL

ANTERIOR





INFERIOR LATERAL

INFERIOR INFERIOR LATERAL

Quiz #8 Where is the elevation or

infarct?





LATERAL SEPTAL LATERAL

ANTERIOR LATERAL

Quiz #9 Where is the elevation or

infarct?




SEPTAL

SEPTAL





LATERAL ANTERIOR

INFERIOR LATERAL LATERAL






SEPTAL ANTERIOR

SEPTAL

ANTERIOR

Thank you for your participation!

Please complete the program and speaker evaluation.

Copyright Apex Innovations 2003

Remove the Mystery from 12 Lead EKG Interpretation for Acute MI The simple, rapid 12 lead solution to 12 lead confusion! A 12 Lead Program for ALL health.

Documents

voltage slide

anatomy slide

positive slide

avr slide

axis slide

heart slide

bpm slide

lead solution