12 Lead EKG Interpretation Advanced Concepts...12 Lead EKG Interpretation Advanced Bundle Branch Blocks V1-V2 = Right precordial leads V5-V6 = Left precordial leads LBBB • Rabbit

12 Lead EKG Interpretation Advanced

12 Lead EKG Interpretation Advanced Concepts

Theresa Wadas PhD, DNP, ACNP-BC, FNP-BC, FAANP Assistant Professor

University of Alabama Capstone College of Nursing

Objectives:

•  Describe methods for axis, hypertrophy, and infarct identification.

•  Demonstrate “putting it all together” for systematic 12 lead EKG interpretation.

•  Review dysrhythmias encountered in clinical practice.

Summary

•  Normal Conduction

•  Leads

•  Normal Waveforms

•  Rate

•  Rhythm

•  Waveform Analysis


12 EKG INTERPRETATION ROADMAP

03 02

04

05

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Practice.

Dysrhythmias

Infarct Putting it all Together

Hypertrophy

Axis

Electrical Conduction in the Heart

Bundle Branch Blocks

V1-V2 = Right precordial leads V5-V6 = Left precordial leads LBBB •  Rabbit ears in V6 represent delay between

depolarization from the septum à to the LV RBBB •  Rabbit ears in V1 represent delay between

depolarization from the septumà to the RV



V1-V2 = Right precordial leads V5-V6 = Left precordial leads LBBB •  Rabbit ears in V6 represent delay between

depolarization from the septum à to the LV RBBB •  Rabbit ears in V1 represent delay between

depolarization from the septumà to the RV


V1 V6

Normal: V1: rS complex

V6: qR complex

RBBB: V1: Rabbit Ears (rSR)

V6: qRS complex

LBBB:

V1: wide QS complex

V6: Rabbit Ears

V1 V6


Right Bundle Branch Block

§  QRS > 0.12 sec §  Predominantly

positive rSR’ in §  V 1-2 §  Wide slurred S

in lead I

LEFT BUNDLE BRANCH BLOCK Left bundle branch block

(Both fascicles are blocked) §  QRS > 0.12 sec §  Deep S in V 1-3 §  Tall R and RsR’ in

lateral leads: I, AVL, & V 5-6

Wide QRS—Why?


Wide QRS—Why?


03 02

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Practice.

Dysrhythmias


Hypertrophy

Axis

Axis Determination Axis refers to the Mean Frontal Plane QRS axis (or vector) during ventricular depolarization. When the ventricles depolarize (in a normal heart) the direction of current flows leftward and downward because most of the ventricular mass is in the left ventricle.


In a “normal” patient the only leads that should have negative polarity are AVR and V1-2

AVF

I

II

III

AVL

V1

V2

V3

V4

V5

V6

AVR

---To determine axis: Look at leads I and AVF

LAD - negative polarity (rS) in AVF

RAD: negative polarity(rS) in lead I


Severe RAD, negative polarity(rS) in 1& AVF

§  Left axis deviation - negative QRS in lead AVF

§  Right axis deviation - negative QRS in lead I

§  Severe Right axis deviation negative QRS in BOTH lead I and AVF

Quick & Easy AXIS DETERMINATION

AVF

AVF

AVF

AVF

AVF

AVF

I

I

I

I

I

I

Why do we care about axis determination in Primary Care, ED, or Acute Care?

Differential Diagnosis LAD : LBBB, LAFB, Mechanical shift due to ascites or

elevated diaphragm, left atrial hypertrophy RAD : RBBB, LPFB, right ventricular hypertrophy,

dextrocardia, Pulmonary Embolism

Both RAD and LAD can be caused by COPD, Hyperkalemia, MI, WPW



03 02

04

05

06

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Practice.

Dysrhythmias


Hypertrophy

Axis

Hypertrophy

Atrial HypertrophyRight Atrial Hypertrophy

Initial

Left Atrial Hypertrophy •  large, diphasic P wave with wide •  terminal component

•

•

‘P’ PULMONALE

‘P’ MITRALE

•  large, diphasic P wave with tall initial component

Hypertrophy: Atrial Enlargement RAE •  P wave is tall and peaked (>2.5mm high) •  OR Biphasic P wave with initial positive inflection •  Dx: Pulmonary HTN, COPD, PE LAE •  P wave is wide (>0.12 sec) and notched in the middle

“M” •  OR Biphasic P wave with terminal negative inflection •  Dx: Systemic HTN, Aortic Insufficiency, Mitral

Stenosis


Atrial Hypertrophy

Hypertrophy

•

•

•

Which Atria is Enlarged?


Which Atria is Enlarged?

II V1

Ventricular Hypertrophy



•  LAD

•  V1,2 deep S and V5,6 tall R >35mm

•  aVL “R” > 12mm

•  Secondary ST depress

•  Most frequently seen with hypertension

•  RAD

•  V1 R + V6 S >10mm

•  V1 rSr’ (incomplete RBBB)

•  Secondary ST depress

•  Usually will be seen with

pulmonary pathology


LVH RVH


§  Add the larger S wave of V1 or V2 in mm, to the larger R wave of V5 or V6.

§  Sum is > 35mm = LVH

Ventricular Hypertropy



03 02

04

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Practice.

Dysrhythmias


Hypertrophy

Axis

Infarct

Infarct


Infarct

Infarct

Infarct


Infarct

Q waves •  Normal Q wave:

–  Small septal Qs in I, aVL, V5, V6 –  Isolated Qs in III, V1

•  Pathologic Q wave: –  wider than 1 small box (0.04 sec) –  OR >25% height of the R wave in that complex

Infarct

Normal Q waves

Normal Q Wave


Abnormal Q Waves

The Q wave makes the diagnosis of

infarction

Infarct and Location





2 EKGs, several hours apart

Acute ST Elevation MI

1.  Normal 2.  Hyperacute

•  T wave Elevation 3.  Acute

•  ST Elevation 4.  Hours Later

•  ST Elev, Q begins to form, T wave inverts 5.  Days Later

•  Q wave, T wave inversion 6.  Weeks Later

•  Q wave


Infarct

A 55 year old man with 4 hours of "crushing" chest pain.


Practice

Practice

Angiography LAD Lesion


Infarct



03 02

04

05

06

01

Practice.

Dysrhythmias

Infarct

Putting it all Together

Hypertrophy

Axis


Putting It All Together Step 1: Rate Step 2: Rhythm + Wave Form Analysis Step 3: Axis Step 4: Hypertrophy Step 5: Infarct

PRACTICE

PRACTICE



03 02

04

05

06

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Practice.

Dysrhythmias


Hypertrophy

Axis

Pericarditis – Diffuse ST segment elevation & PR depression, with PR elevation in AVR

Pulmonary Emboli


Pulmonary Emboli

A 76 year old man with breathlessness.

AV

SA

Accessory Pathways-WPW

If narrow QRS d/t forward conduction, treat as SVT (Adenosine)

Wide QRS b/c retrograde conduction –10%


Wolff-Parkinson-White-Syndrome

Wolff-Parkinson-White-Syndrome

Wellen’s Sign

ST elevation and biphasic T wave in V2 and V3 Sign of large proximal LAD lesion


Brugada Syndrome

RBBB or incomplete RBBB in V1-V3 with convex ST elevation

Brugada Syndrome •  Autosomal dominant genetic

mutation of sodium channels •  Causes syncope, v-fib, self

terminating VT, and sudden cardiac death

•  Can be intermittent on EKG •  Most common in middle-

aged males •  Can be induced in EP lab •  Need ICD

A 72 year old man on routine office visit


Ventricular Pacemaker

• Pacer spikes—hard to see! • Wide QRS complexes • Pacemaker starts after a long R - R interval following a blocked atrial premature beat...then NSR

Pacemakers

Implantable Defibrillator

AICD Automated Implanted Cardio-

Defibrillator Uses

Tachyarrhythmias Malignant arrhythmias

VT VF

Programmed at insertion to deliver predetermined therapies with a set order and number of therapies including:

pacing overdrive pacing cardioversion with increasing energies defibrillation with increasing energies standby mode


Implantable Defibrillators

Implantable Defibrillators


03 02

04

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Practice.

Dysrhythmias


Hypertrophy

Axis


PRACTICE 58 year old female presents with profound weakness and shortness of breath

PRACTICE 72 year old male with history of COPD now presents with syncope

PRACTICE 72 year old male with history of COPD now presents with chest pain


§  Normal Resting ECG – cannot exclude disease

§  Ischemia may be covert – supply / demand equation

§  Changes of MI take some time to develop in ECG

§  Mild Ventricular hypertrophy - not detectable in ECG

§  Some of the ECG abnormalities are non specific

§  Single ECG cannot give progress – Need serial ECGs

§  ECG changes may not co-relate with Angio results

§  Paroxysmal event may be missed in single ECG

Beware of Normal EKG

•  EKG is a diagnostic tool, dependent on the interpretor •  •  Correct Lead placement and good contact

•  Compare serial ECGs if available

•  Relate the changes to Age, Sex, Clinical history

•  Consider the co-morbidities that may effect ECG

•  Review EKG systematically

Take Home Message

References •  Anderson, D. (2016). EKG/ECG interpretation:

Everything you need to know about 12 lead ECG/EKG interpretation and how to diagnosis and treat arrhythmias. Buffalo, WY: Medical Creations.

•  Garcia, T. (2015). The art of interpretation. Burlington, MA: Jones & Bartlett.



PRACTICE ! PRACTICE! PRACTICE!

Documents

12 Lead EKG Interpretation Advanced Concepts...12 Lead EKG Interpretation Advanced Bundle Branch Blocks V1-V2 = Right precordial leads V5-V6 = Left precordial leads LBBB • Rabbit