Download - 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)
Wide Complex TachycardiaWide Complex Tachycardia
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
Wide Complex TachycardiaWide Complex Tachycardia
• There are many indicators that rule VT in, but very few that rule VT out.
Wide Complex TachycardiaWide Complex Tachycardia
• 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
Precordial ConcordancePrecordial Concordance
I aVR V1 V4
II aVL V2 V5
II aVF V3 V6
Positive Concordance
Precordial ConcordancePrecordial 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
Rate: 88Normal Sinus
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
Rate: 88Normal Sinus
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
62 y/o MaleIntervals & Morphology
Rate: 88Normal SinusFrontal Axis: 30 Precordial Axis: Normal
62 y/o MaleIntervals & Morphology
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
62 y/o MaleSTE-Mimics
Rate: 88Normal SinusFrontal Axis: 30 Precordial Axis: NormalHyperacute T-waves
62 y/o MaleSTE-Mimics
Rate: 88Normal SinusFrontal Axis: 30 Precordial Axis: NormalHyperacute T-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
Rate: 88Normal SinusFrontal Axis: 30 Precordial Axis: NormalHyperacute T-waves
62 y/o MaleIschemia, Injury, Infarct
Rate: 88Normal SinusFrontal Axis: 30 Precordial Axis: NormalHyperacute T-waves
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
Rate: 88Normal SinusFrontal Axis: 30 Precordial Axis: NormalHyperacute T-waves
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
Rate: 114Sinus Tachycardia
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
Rate: 114Sinus TachycardiaFrontal Axis: NormaClockwise RotationLBBB
72 y/o Female
Ischemia, Injury, Infarct
Rate: 114Sinus TachycardiaFrontal Axis: NormaClockwise RotationLBBB
73 y/o MaleDiaphoresis
73 y/o MaleRate & Rhythm
73 y/o MaleAxis
Rate: 71Normal Sinus - 1st AVB
73 y/o MaleAxis
Rate: 71Normal Sinus - 1st AVB
ERAD LAD
RAD Normal
180 0
-90
90
73 y/o MaleAxis
Rate: 71Normal Sinus - 1st AVB
73 y/o MaleAxis
Rate: 71Normal Sinus - 1st AVB
- I I +
aVF +
aVF -
73 y/o MaleAxis
Rate: 71Normal Sinus - 1st AVB
73 y/o MaleAxis
Rate: 71Normal Sinus - 1st AVB
- I I +
aVF +
aVF -
73 y/o MaleAxis
Rate: 71Normal Sinus - 1st AVB
- I I +
aVF +
aVF -
73 y/o MaleAxis
Rate: 71Normal Sinus - 1st AVB
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
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave Progression
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
73 y/o MaleIntervals & Morphology
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave Progression
73 y/o MaleIntervals & Morphology
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave Progression
73 y/o MaleIntervals & Morphology
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave Progression
73 y/o MaleIntervals & Morphology
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave Progression
73 y/o MaleIntervals & Morphology
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave Progression
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
73 y/o MaleSTE-Mimics
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave ProgressionRBBB
73 y/o MaleSTE-Mimics
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave ProgressionRBBB
73 y/o MaleSTE-Mimics
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave ProgressionRBBB
73 y/o MaleIschemia, Injury, Infarct
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave ProgressionRBBB
73 y/o MaleIschemia, Injury, Infarct
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave ProgressionRBBB
73 y/o Male
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave ProgressionRBBB
73 y/o MaleIschemia, Injury, Infarct
Rate: 71Normal Sinus - 1st AVBRight Axis DeviationEarly R-Wave ProgressionRBBBAntero-Septal Infarct
B
76 y/o FemaleShortness of Breath
76 y/o FemaleRate & Rhythm
76 y/o FemaleRate & Rhythm
1 2 3 4 5 6
76 y/o FemaleRate & Rhythm
1 2 3 4 5 6 7 8 9 10 11 12 13
76 y/o FemaleRate & Rhythm
1 2 3 4 5 6 7 8 9 10 11 12 13 13 x 10 = 130
76 y/o FemaleAxis
Rate: 133Sinus Tachycardia
76 y/o FemaleAxis
Rate: 133Sinus Tachycardia
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
Rate: 133Sinus TachycardiaNormal Axis
76 y/o FemaleIntervals & Morphology
Rate: 133Sinus TachycardiaNormal Axis
76 y/o FemaleSTE-Mimics
Rate: 133Sinus TachycardiaNormal Axis
76 y/o FemaleSTE-Mimics
Rate: 133Sinus TachycardiaNormal Axis
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
Rate: 133Sinus TachycardiaNormal Axis
76 y/o Female
Rate: 133Sinus TachycardiaNormal Axis
76 y/o FemaleIschemia, Injury, Infarct
Rate: 133Sinus TachycardiaNormal AxisInfero-Posterior & Lateral MI
B