12 lead-lesson 6

12-Lead 12-Lead ElectrocardiographyElectrocardiography

a comprehensive course

Adam Thompson, EMT-P, A.S.Adam Thompson, EMT-P, A.S.

Lesson

6

Lesson SixLesson Six

• Review Wide Complex Tachycardia (WCT)Review Wide Complex Tachycardia (WCT)• Briefly discuss treatment strategies for Briefly discuss treatment strategies for

arrhythmiasarrhythmias• Discuss paced rhythmsDiscuss paced rhythms• Practice the 6-Step method of ECG interpretation Practice the 6-Step method of ECG interpretation

Objectives

• Learn how to apply an appropriate treatment strategy for wide complex tachycardias.

• Learn how to identify paced rhythms• Apply all skills learned throughout the

course.

The 6-Step MethodThe 6-Step Method

• 1. Rate & Rhythm1. Rate & Rhythm• 2. Axis Determination2. Axis Determination• 3. Intervals3. Intervals• 4. Morphology4. Morphology• 5. STE-Mimics5. STE-Mimics• 6. Ischemia, Injury, & Infarct6. Ischemia, Injury, & Infarct

Wide Complex TachycardiaWide Complex Tachycardia

• Ventricular Tachycardia

• SVT with aberrancy– Bundle Branch Block– Accessory Pathway (WPW/LGL)


All WCTs are Ventricular Tachycardia

until PROVEN otherwise!

Treatment Strategy

• If unstable, SHOCK!

• If stable– Try to determine if supraventricular or not.– Unsure? Treat as Ventricular Tachycardia!

Treatment Strategy


• There are many indicators that rule VT in, but very few that rule VT out.


• Factors that favor V-Tach– AV Dissociation– Capture Beats & Fusion Beats– Non-conducted P-waves– A regular rhythm– QRS Morphology

• wide, Brugada’s, Josephson’s

– Extreme Right Axis Deviation– Concordance in precordial leads– History of MI, CHF, or structural heart disease– Physical Exam

• Cannon A-Waves, no vagal response

AV Dissociation

• Different than 3rd degree AVB– Ventricular depolarization is faster than

atrial depolarization (more QRS complexes than P-waves)

• No correlation between P-wave & QRS complex

Capture Beats

• In the presence of AV dissociation.• When the atrial depolarization triggers a

single QRS complex of different morphology than the rest

• The complex is narrow with a preceding P-wave.

Fusion Complexes

• In the presence of AV dissociation.• When the atrial depolarization and ventricular

depolarization both occur at the same time, fusing together both of their complexes.

• Will look different than the rest of the QRS-complexes

Non-Conducted P-Waves

• Atrial-ventricular dissociation

• Upright P-waves in leads II, III, or aVF tell us that the atrial depolarization is coming from right atrium.

Regularity

• Monomorphic ventricular tachycardia is very regular.

• Polymorphic ventricular tachycardia appears bizarre and irregular

• Torsades de Pointes has an unmistakable pattern

QRS Width

• A QRS width of greater than 140 ms tips the scale heavily in favor of V-tach.

• Brugada’s Sign– Interval from beginning of QRS to tip of S-

wave (Nadir) > 100 ms (0.10 sec)

Josephson’s Sign

• A notch or slurring on the down-slope of the S-wave

Josephson’s Sign

Josephson’s Sign

QRS Morphology

• In Lead V1– R > R’– If the first R-wave is taller than the second

R-wave in V1, V-tach is highly likely.– This is just one possible morphology of VT.

QRS Morphology

RBBB Morphology VT Morphology

V1 V1

QRS MorphologyQRS Morphology

• PVCs of similar morphology favors VTPVCs of similar morphology favors VT– The presence of a supraventricular rhythm The presence of a supraventricular rhythm

with PVCs that changes to a WCT, and the with PVCs that changes to a WCT, and the QRS morphology looks similar to the QRS morphology looks similar to the previous PVCs. previous PVCs.

ERADERAD

• Extreme Right Axis DeviationExtreme Right Axis Deviation– A frontal axis of -90A frontal axis of -90 to -180 to -180– Negative QRS in lead I & aVFNegative QRS in lead I & aVF

ERAD

I aVR V1 V4

II aVL V2 V5

II aVF V3 V6

Extreme Right Axis

Precordial ConcordancePrecordial Concordance

• QRS Concordance in Precordial LeadsQRS Concordance in Precordial Leads– Every QRS complex is positive, orEvery QRS complex is positive, or– Every QRS complex is negativeEvery QRS complex is negative


I aVR V1 V4

II aVL V2 V5

II aVF V3 V6

Positive Concordance


I aVR V1 V4

II aVL V2 V5

II aVF V3 V6

Negative Concordance

Past Medical HistoryPast Medical History

• Significant cardiac history is suggestive of ventricular tachycardia– Long list of cardiac meds– Previous heart attack– Previous episodes of v-tach

Physical ExamPhysical Exam

• Cannon A-Waves– Observable pulsations in the neck that indicate

complete AV dissociation.

• Vagal Response– The vagus nerve does not innervate the ventricles.– Vagal maneuvers will only work in the presence of

a supraventricular rhythm.

SVT With RBBB

Ventricular Tachycardia

WCT Change

Practice

• Lets take a look at some 12-Lead recordings and use the 6-step method to interpret them.

62 y/o MaleComplaining of Chest Pain

62 y/o MaleRate & Rhythm

62 y/o MaleAxis

Rate: 88Normal Sinus

62 y/o Male

62 y/o MaleAxis


62 y/o Male

Hexaxial Reference System

• When the mean axis is perpendicular to the positive electrode, the QRS is equiphasic.

+

+

+ A B A

B

62 y/o Male

62 y/o MaleAxis


62 y/o Male

62 y/o Male

ERAD LAD

RAD Normal

180 0

-90

90

62 y/o MaleAxis

Rate: 88Normal SinusFrontal Axis: 30

Precordial Axis

V1

V2

V3

V4

V5V6

Normal transition

62 y/o MaleAxis

Rate: 88Normal SinusFrontal Axis: 30

62 y/o MaleIntervals & Morphology

Rate: 88Normal SinusFrontal Axis: 30 Precordial Axis: Normal


Rate: 88Normal SinusFrontal Axis: 30 Precordial Axis: Normal

HyperacuteT-Waves

62 y/o MaleSTE-Mimics

Rate: 88Normal SinusFrontal Axis: 30 Precordial Axis: NormalHyperacute T-waves



Lead I

lateral

aVR V1

septal

V4

anterior

Lead II

inferior

aVL

high lateral

V2

septal

V5

low lateral

Lead III

inferior

aVF

inferior

V3

anterior

V6

low lateral

62 y/o MaleIschemia, Injury, Infarct




Site Facing Reciprocal

Septal V1, V2 V7, V8, V9

Anterior V3, V4 None

Lateral I, aVL, V5, V6 II, III, aVF

Inferior II, III, aVF I, aVL

Posterior V7, V8, V9 V1, V2

62 y/o Male12-Lead #2


62 y/o Male

Rate: 88Normal SinusFrontal Axis: 30 Precordial Axis: NormalHyperacute T-wavesAntero-Septal MI

72 y/o Female

Recent Syncope

QuickTime™ and a decompressor

are needed to see this picture.

72 y/o Female

Rate & Rhythm

72 y/o Female

Rate & Rhythm

10 Seconds

72 y/o Female

Rate & Rhythm

10 Seconds

1 2 3 4 5 6 7 8 9 11 12 13 1410 15 16 17 18 19

72 y/o Female

Rate & Rhythm

10 Seconds

1 2 3 4 5 6 7 8 9 11 12 13 1410 15 16 17 18 19

19 x 6 = 114

72 y/o Female

Rate & Rhythm

Rate: 114

72 y/o Female

Rate & Rhythm

Rate: 114Sinus Tachycardia

72 y/o Female

Axis


Cheat SheetNormal

Axis

0 to 90

Physiologic

Left

0 to -30

Pathologic

Left

-30 to -90

Right Axis

90 to 180

Extreme Right Axis

-90 to 180

Indeterminate

Axis

?

Lead I

Lead II

Lead III

72 y/o Female

Axis

Rate: 114Sinus TachycardiaFrontal Axis: Normal

72 y/o Female

Intervals & Morphology

Rate: 114Sinus TachycardiaFrontal Axis: NormaClockwise Rotation

Bundle Branch BlocksBundle Branch Blocks

= RBBB

= LBBB

V1

V1

BBB ChartBBB Chart

RBBB LBBB IVCD

V1 TERMINAL

R-WAVE

TERMINAL

S-WAVE

TERMINAL

R/S-WAVE

I & V6 TERMINAL

S-WAVE

TERMINAL

R-WAVE

Anything is possible

72 y/o Female

Intervals & Morphology

Rate: 114Sinus TachycardiaFrontal Axis: NormaClockwise RotationLBBB

72 y/o Female

STE-Mimics


72 y/o Female

Ischemia, Injury, Infarct


73 y/o MaleDiaphoresis

73 y/o MaleRate & Rhythm

73 y/o MaleAxis

Rate: 71Normal Sinus - 1st AVB

73 y/o MaleAxis


ERAD LAD

RAD Normal

180 0

-90

90

73 y/o MaleAxis


73 y/o MaleAxis


- I I +

aVF +

aVF -

73 y/o MaleAxis


73 y/o MaleAxis


- I I +

aVF +

aVF -

73 y/o MaleAxis


ERAD LAD

RAD Normal

180 0

-90

90

73 y/o MaleAxis

Rate: 71Normal Sinus - 1st AVBRight Axis Deviation

73 y/o MaleAxis

Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave Progression

73 y/o MaleAxis


Frontal Plane Axis Precordial Axis

ERAD-90 to 180

Right Axis Deviation90 to 180

Pathological Left Axis Deviation-30 to -90

Early TransitionCounterclockwise

Rotation

Late TransitionClockwise Rotation

• Ventricular Rhythm• Paced Rhythm• Dextrocardia• Electrolyte derangement

• May be normal• LPFB• Pulmonary disease• RVH• RBBB• WPW• Dextrocardia•Venrticular Rhythm

• Pregnancy• LAFB• WPW• Pulmonary disease• LBBB• Hyperkalemia• Q-waves, MI

• Posterior wall infarction• RVH• RBBB

• Sometimes Normal, especially in women• Anterior MI• LVH• LAFB• LBBB• Lung Disease



Frontal Plane Axis Precordial Axis

ERAD-90 to 180

Right Axis Deviation90 to 180

Pathological Left Axis Deviation-30 to -90

Early TransitionCounterclockwise

Rotation

Late TransitionClockwise Rotation

• Ventricular Rhythm• Paced Rhythm• Dextrocardia• Electrolyte derangement

• May be normal• LPFB• Pulmonary disease• RVH• RBBB• WPW• Dextrocardia•Venrticular Rhythm

• Pregnancy• LAFB• WPW• Pulmonary disease• LBBB• Hyperkalemia• Q-waves, MI

• Posterior wall infarction• RVH• RBBB

• Sometimes Normal, especially in women• Anterior MI• LVH• LAFB• LBBB• Lung Disease


Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave ProgressionRBBB

73 y/o Male



Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave ProgressionRBBBAntero-Septal Infarct

B

76 y/o FemaleShortness of Breath

76 y/o FemaleRate & Rhythm


1 2 3 4 5 6


1 2 3 4 5 6 7 8 9 10 11 12 13


1 2 3 4 5 6 7 8 9 10 11 12 13 13 x 10 = 130

76 y/o FemaleAxis


76 y/o FemaleAxis


Lead I aVF

Normal Positive (+) Positive (+)

RAD Negative (-) Positive (+)

LAD Positive (+) Negative (-)

ERAD Negative (-) Negative (-)

76 y/o FemaleAxis

Rate: 133Sinus TachycardiaNormal Axis

76 y/o FemaleIntervals & Morphology


76 y/o FemaleSTE-Mimics


76 y/o FemaleSTE-Mimics


E - Electrolytes (hyperkalemia)

L - LBBB

E - Early repolarization

V - Ventricular hypertrophy (LVH)

A - Aneurysm

T - Treatment (e.i. pericardiocentesis)

I - Injury (AMI, contusion)

O - Osborne waves (hypothermia)

N - Non-occlusive vasospasm

E - Electrolytes (hyperkalemia)

L - LBBB

E - Early repolarization

V - Ventricular hypertrophy (LVH)

A - Aneurysm

T - Treatment (e.i. pericardiocentesis)

I - Injury (AMI, contusion)

O - Osborne waves (hypothermia)

N - Non-occlusive vasospasm

76 y/o FemaleIschemia, Injury, Infarct


76 y/o Female


76 y/o FemaleIschemia, Injury, Infarct

Rate: 133Sinus TachycardiaNormal AxisInfero-Posterior & Lateral MI

B

Lesson 6

• This concludes the course

• Questions or feedback?– [email protected]

12 lead-lesson 6

Health & Medicine

Transcript of 12 lead-lesson 6