12 Lead EKG Interpretation

1. Unraveling the
Mysteries of the
12 Lead EKG
Developed by the

2. Objectives
• Identify the correct lead placement for
performing a 12 lead EKG
• Identify and interpret heart rhythm and
differing blocks
• Identify extreme axis deviations
• Identify and interpret bundle branch blocks
• Interpret MI location based on ST elevation
2

3. ECG Pre-test
3

4. • Is this ECG normal?
A. True
B. False
4

5. • Is this ECG normal?
A. True
B. False - Wenkebach
5

6. • Would you call a STEMI alert?
A. Yes
B. No
6

7. • Would you call a STEMI alert?
A. Yes
B. No - RBBB
7

8. • Does this person need anticoagulation?
A. Yes
B. No
8

9. • Does this person need anticoagulation?
A. Yes – Atrial fibrillation
B. No
9

10. • The initial treatment of choice for this rhythm is
cardioversion.
A. True
B. False
10

11. • The initial treatment of choice for this rhythm is
cardioversion.
A. True
B. False – SVT (try adenosine first)
11

12. • This ECG explains the patient’s complaints of
dizziness.
A. True
B. False
12

13. • This ECG explains the patient’s complaints of
dizziness.
A. True – sinus bradycardia with heart rate of 37 bpm
B. False
13

14. How did you do?
OK – let’s get started!!
14

15. Monitoring vs Assessing
• Monitoring – EKG leads can be placed
anywhere
– Allows for identification of VF and Asystole
• Assessing – EKG leads MUST be placed in
specific locations
– Allows for interpretation of changes in the
electrical conduction (depolarization and
repolarization changes) i.e., ischemia.
16

16. Patient Preparation
• Provide a level of privacy
• Remove the patient’s shirt
• Shave the chest
• Prep the skin
– Remove the dead epithelials
• Electrically non-conductive
• Place the patient in a
hospital gown

17. YES! – Women Too
• Remove the bra
• Use a sheet to drape the patient
• Diaphoresis
– Dry the chest
– Use alcohol
– Use benzene

18. Patient Position
• Place the patient in the correct position to
acquire the EKG
– Supine Recommended
– Sitting up is fine
• Ask the patient to hold still
• Keep their hands down by their side
– May need to hold the patient’s hands
19

19. Lead Placement
• 12 Lead ECG’s use 10 Electrodes
– one electrode on each limb
– 6 electrodes on the left chest
20

20. Lead Placement
• Limb Lead go on the LIMBS!
– LA Left ARM
– RA Right ARM
– LL Left LEG
– RL Right LEG
21

21. Left Chest Lead Placement
• Precordial Leads (V leads or MCL leads)
– V1 4th intercostal space, right of sternum
– V2 4th intercostal space, left of the sternum
– V3 between V4 and V2
– V4 5th intercostal space, left of sternum
– V5 5th intercostal space, left of sternum
– V6 5th intercostal space, left of sternum
22

22. Left Chest EKG
23

23. The Normal Conduction System
24

24. Normal ECG
25

25. Limb Lead Reversal
26

26. Limb Lead Reversal
27

27. Waveforms
28

28. QRS Labeling
Q Waves
First negative deflection after the
P waves in any lead
Q wave

29. QRS Labeling
R Waves
First positive deflection after the
P waves in any lead
"R"

30. QRS Labeling
S Wave
Negative deflection below the
baseline after an "R" or "Q" wave
s
QS
s

31. QRS Labeling
The "J" Point
Also called the" juncture" point.
Where the qrs complex ends
and the ST segment begins
32

32. QRS Labeling
QRS Morphologies
Can you label these complexes?
R
QS
q
R
s
r
S q
R
r
S
R’
33

33. Now YOU Do It!
• Video of proper ECG lead placement
34

34. Interpretation
• Develop a systematic approach to reading
EKGs and use it every time
• The system recommended is:
– Rate
– Rhythm (including intervals and blocks)
– Axis
– Ischemia
35

35. Rate
• Rule of 300- Divide 300 by the number of
boxes between each QRS = rate
Number of
big boxes
Rate
1 300
2 150
3 100
4 75
5 60
6 50
36

36. Estimate of Heart Rate
37

37. What is the heart rate?
(300 / 6) = 50 bpm
www.uptodate.com
38

38. Rate
• HR of 60-100 per minute is normal
• HR > 100 = tachycardia
• HR < 60 = bradycardia
39

39. Differential Diagnosis of Tachycardia
Tachycardia Narrow Complex Wide Complex
Regular ST
SVT
Atrial flutter
ST w/ BBB
SVT w/ BBB
VT
Irregular A-fib
A-flutter w/
variable conduction
MAT
A-fib w/ BBB
A-fib w/ WPW
VT
40

40. Rhythm
• Sinus
– Originating from SA
node
– P wave before
every QRS
– P wave in same
direction as QRS
41

41. What is this rhythm?
42

42. Normal Intervals
• PR
– 0.20 sec (less than one
large box)
• QRS
– 0.08 – 0.10 sec (1-2 small
boxes)
• QT
– 450 ms in men, 460 ms in
women
– Based on sex / heart rate
– Half the R-R interval with
normal HR
43

43. Causes of Prolonged QT
• Causes
– Drugs
– Hypocalcemia,
hypomagnesemia,
hypokalemia
– Hypothermia
– AMI
– Congenital
– Increased ICP
44

44. Consequences of Prolonged QT
45

45. Blocks
• AV blocks
– First degree block
• PR interval fixed and > 0.2 sec
– Second degree block, Mobitz type 1
• PR gradually lengthened, then drop QRS
– Second degree block, Mobitz type 2
• PR fixed, but drop QRS randomly
– Type 3 block
• PR and QRS dissociated
46

46. What is this rhythm?
47

47. What is this rhythm?
First degree AV block
PR is fixed and longer than 0.2 sec
48

48. What is this rhythm?
49

49. What is this rhythm?
Type 1 second degree block (Wenckebach)
50

50. What is this rhythm?
51

51. What is this rhythm?
52

52. What is this rhythm?
53

53. What is this rhythm?
3rd degree heart block (complete)
54

54. Section Two
55

55. Axis
• Axis: predominant
flow of electricity
through the heart
• We look at the QRS
complexes for
ventricular axis

56. III II
I
NORMAL AXIS
57

57. Hexaxial Reference System
• Divided into 6 part grid
– Based on the leads
• I
• II
• III
• aVR
• aVF
• aVL
• Degrees of electrical flow
– 0 to +180
– 0 to -180
58

58. ECG with Normal Axis
59

59. Extreme Right Axis
-90 to -180 degrees
60

60. ECG with Extreme Right Axis
61

61. Differential Diagnosis of Extreme Right
Axis
• Ventricular tachycardia
• Hyperkalemia (acute renal failure)
• Apical MI
• Right Ventricular Hypertrophy
62

62. Limb Lead Reversal
63

63. Hemiblocks
• A hemiblock is a block
of one of the fascicles
of the left bundle
branch.
• Hemiblock is an ECG
diagnosis
Left Bundle Branch
Posterior Hemifascicle
Anterior Hemifascicle

64. Hemiblocks
• Anterior Hemiblock
– pathological left axis
– negative deflection in
leads II and III
– small q in lead I, small
r in lead III
– common block
– 4x higher mortality
rate in AMI
Left Bundle Branch
Anterior Hemifascicle

65. Anterior Hemiblock
66

66. Hemiblocks
• Posterior Hemiblock
– right axis deviation
– small r in lead I, small
q in lead III
– high mortality rate
when with an AMI
– two coronary arteries
involved
Left Bundle Branch
Posterior Hemifascicl

67. Posterior Hemiblock
• Very rare and much more dangerous.
• Posterior hemifascicle has redundant
blood supply from two separate
coronary arteries.
• In setting of an acute MI, two coronary
arteries would have to be occluded
proximally in order to create this
condition.

68. Posterior Hemiblock
69

69. Rapid Axis
• Rapid Axis and Hemiblock Chart
Lead I Lead II Lead III
Axis
Normal Axis
0 - 90
Physiologic
Left Axis
0 to -40
Pathological
Left Axis
-40 to -90
Right Axis
90 - 180
Extreme Right
Axis
Anterior
Hemiblock
Hemiblock
Posterior
no man's land
Ventricular in
origin
Comments
70

70. Test Your Knowledge!
71

71. Normal Axis
Leftward Axis
(normal)
Left Anterior Hemiblock
Left Posterior Hemiblock
Extreme Right Axis
72

72. Ventricular Tachycardia
• 12 Lead ECG and VT:
• You may be the only one
to see the rhythm
• A 12 lead ECG of VT is
very helpful to the
cardiologist looking for
the cause
• More benefit and less risk
in knowing for sure

73. Ventricular Tachycardia
• Rate 110 -250 bpm
• Wide complex (>0.12 – 3 small blocks)
• Regular
• AV dissociation
• Extreme Right Axis Deviation + Upright MCL-1
I II
I II III
MCL-1

74. I
II
III
EXTREME RIGHT AXIS
ERAD
V1
75

75. VT
76

76. Bundle Branch Blocks
• A Bundle Branch Block is a block of one of the
two bundle branches, left or right
• A Bundle Branch is a fascicle of electrical
conduction system cells designed to carry
impulses to the ventricles
• Bundle Branches facilitate “syncytium” or
both ventricles contracting in sync.
77

77. Bundle Branch Blocks
• Turn Signal Theory
– easy way to
determine left or right
BBB
– use lead V1
– QRS complex must be
at least .12sec (120
ms) or wider (or 3
little squares)

78. Bundle Branch Blocks
• Turn Signal Theory
– Use lead V1 or MCL-1 IF QRS > 120 ms (.12 sec)
– Circle the J point
– Draw line back into the complex, then up or down
with the terminal deflection
– shade in the triangle made by this line
– Arrow points up - turn signal up - Right BBB
– Arrow points down - turn signal down - Left BBB
79

79. Bundle Branch Blocks
• Turn Signal Theory
1 2 3
LBBB
RBBB

80. QRS Labeling
QRS Morphologies
Can you label these complexes?
RBBB
LBBB LBBB
LBBB
RBBB RBBB
Can You Identify These
Bundle Branch Blocks?
81

81. Right Bundle Branch Block and
Hemiblocks can occur together!
RBBB + Anterior Hemiblock (most commonly seen)
Left Bundle Branch
Anterior Hemifascicle
Right Bundle Branch

82. RBBB + LAHB
83

83. Section Three
84

84. Myocardial Blood Supply
85

85. AMI
Myocardial Blood Supply
• Right Coronary Artery
• Inferior Wall (LV)
• Posterior Wall (LV)
• Right Ventricle
• SA and AV Node
• Posterior fascicle of LBB

86. Myocardial Blood Supply
• Left Anterior Descending
• Anterior Wall of LV
• Septal Wall
• Bundle of His and BB

87. Myocardial Blood Supply
• Circumflex
• Lateral Wall of LV
• Rarely SA and AV nodes
• Posterior Wall of LV

88. Clinical Manifestations of
Arterial Thrombosis
UA/NSTEMI:
Partially-occlusive thrombus
(primarily platelets)
Intra-plaque
thrombus (platelet
dominated)
Plaque core
ST  MI:
Occlusive thrombus (platelets,
red blood cells, and fibrin)
Intra-plaque
thrombus (platelet
dominated)
Plaque core
SUDDEN DEATH
Adapted from Davies MJ. Circulation. 1990; 82 (supl II): 30-46.

89. ECG Signs of Ischemia
• Usually indicated by ST changes
– Elevation = Acute infarction
– Depression = Ischemia
• Can manifest as T wave changes
• Remote infarction can be shown by q waves
90

90. ECG Progression
in Infarct
• ECG pattern in AMI =
continuum that extends
from normal to full infarct.
• First: T wave flips in early
ischemia.
• Then: ST elevation either
flat or tombstoning
(flipped T wave may
disappear).
• Finally: We see Q waves.
91

91. 12 Lead ECG and AMI
• Benefits of 12 Lead ECG’s
– Highly specific (90% + confidence)
– If it shows an MI, there probably is an MI
– Rapid identification of MI in early stages
– Can commit to treat with ECG, history and
physical exam
– Complications can be identified
92

92. 12 Lead ECG and AMI
• Limitations
– Only 46 - 50 % sensitive (may miss 50%)
• Increase sensitivity by looking at the whole heart
– Diagnostic quality necessary
– Training needed to read the 12 leads
– ECG evidence is only one piece of the puzzle
– Some non-MI conditions look like MI’s
93

93. 12 Lead ECG and AMI
A NORMAL 12 LEAD ECG DOES NOT
RULE OUT A MYOCARDIAL
INFARCTION
If there is suspicion for MI, repeat the
ECG
94

94. Acute Ischemia
• Area of ischemia is more negative than surrounding normal tissue
• Causes ST depression; T wave is flipped
• Causes repolarization to occur along abnormal pathway
95

95. Acute Injury
• Zone of injury does not repolarize completely
• Remains more positive than surrounding tissue, leading to ST
elevation
• T remains flipped (abnormal repolarization paths along
injured/ischemic areas of myocardium)
96

96. Cardiac Location of Event
97

97. Posterior MI
Is there a lead for that?
• You only find what you’re looking for!
– Move V4, V5, V6
– 5th intercostal space
98

98. Posterior MI
• Look for anterior reciprocal changes
99

99. What about the right side?
RV infacts
• Move V4 to the
right side same
location
– 5th intercostal
space anterior
axillary
Occur in conjunction with inferior MIs
100

100. Acute MI with RV involvement
101

101. Where/What is It?
102

102. Where/What is It?
103

103. Where/What is It?
104

104. Where/What is It?
105

105. 106

106. Scorecard
• The guidelines call for a 90 minute medical
contact to balloon time.
• Very important to perform immediate or in-
field ECG to make earlier diagnosis to start the
STEMI alert.
107

107. Interventional Plan for EMS
• Out of hospital 12 lead
• Early notification of
hospital
• O2, NTG, pain control
• ASA, Heparin
• Thrombolytic prescreen
• Transport to PCI Center

108. Definitive AMI Treatment
Percutaneous Coronary Intervention

109. When to Consider Thrombolytics
• Acute MI patients in whom first medical
contact to balloon time is like to exceed
2 hours.
• Cath lab is not available.
110

110. How do thrombolytics or more
appropriately fibrinolytics work?
t-PA
• A naturally occurring blood protein
Plasminogen activates the production of
plasmin – a digestive enzyme
• Presence of a clot causes the endothelia cells
to secrete tissue plasminogen activator which
starts the breakdown of the clot
111

111. How do fibrinolytics work?
• Fibrinolytics
– Destroy the clot
at the level of the fibrin.
– Activate the production
of plasmin to cause the
digestion of the clot
112

112. EMS and the AMI:
Making a difference
• Early recognition and treatment
• Early activation of cath lab
• Once infarction begins 500
myocardial cells die each second
• Salvage myocardium
• Decreased incidence of CHF
• Maintain active lifestyles

113. Infarct Caveats
• Anterior Wall MI
– most lethal (highest mortality)
– can suddenly develop, CHB, VF or VT
– if seen with hemiblocks or BBB, place quick
combo pads on the patient and prepare for
the worst
– can extend to septum (anteroseptal) or lateral
(anterolateral)
– nitrates are great, fluids are spared
114

114. Infarct Caveats
• Inferior MI
– Most common seen. Can be fatal
– 50% have posterior and right ventricle involved
– Patients may have bradycardia and hypotension
– Could also have 1st degree or Mobitz 1 blocks
– Nausea is common, phenergan or compazine
– Use nitrates with caution, may need fluids
115

115. Infarct Imitators
• Left Bundle Branch Block
– late depolarization makes ST
elevation difficult to distinguish
– LBBB considered a non-diagnostic
ECG
• Left Ventricular Hypertrophy
– won’t have reciprocal changes
• Early Repolarization

116. (…but is it really benign?)
Benign early repolarization

117. Who gets it?
• 2-5% of the general population (Wellens,
2008)
• Usually the young and physically fit
• More prominent in African-Americans
• Generally disappears with advancing age
118

118. What does it look like?
Red arrows: concave up ST-segment elevation anteriorly
Blue arrows: hyperdynamic, symmetrical, concordant T-waves 119

119. Classic findings
1. J-point “notching”
2. Concave-up ST segment
(smiley face)
3. ST segment elevation
from baseline in V2-V5,
typically <3mm
4. Large, symmetrically
concordant T-waves in
leads with STE
120

120. Can we tease it out?
• The degree of ST segment elevation is thought to
be indirectly proportional to the degree of
sympathetic tone
• In other words, the more relaxed the patient, the
more pronounced the ST segment elevation (and
vice versa)
• If you truly want to test your patient, get their
heart rate up and look at the ST segment
121

121. 14yo M w/ palpitations
HR: 64
122

122. 1. Notched J-point
2. Concave down ST
elevation in
precordial leads
123

123. Same patient after asking him to do 2min of jumping jacks in the room to try and
get his heart rate up…
HR 83 (up 20bpm from previous) 124

124. HR 64 HR 83
The ST segment is NOT fixed in pts w/ BER and changes from EKG to EKG and with the
degree of sympathetic strain
On the right, note the complete resolution of the ST elevation but maintenance of the
J-point notching in V4
125

125. Early Repolarization
• Should be a diagnosis of exclusion and should ALWAYS be
placed in clinical context!!!
• The above was taken in a patient with difficulty breathing and
chest pain…and is an Myocardial Infarction -- NOT Early
Repolarization!!! 126

126. Pericarditis
• Pericarditis is an inflammation of the
pericardium (sac that surrounds the heart).
• This often occurs as a result of a viral
infection.
• However, this can cause severe chest pain and
can lead to ST elevation in all leads.
• Therefore, it is important to distinguish acute
pericarditis from acute myocardial infarction.
127

127. Pericarditis
• Diffuse ST elevation
128

128. Pericarditis
• PR segment depression, usually in lead II
129

129. Pericarditis Treatment
• NSAIDs
• Colchicine
• Occasionally steroids
• Anticoagulation could cause a hemorrhagic
pericardial effusion – life threatening.
130

130. Section 4
• ECG Tests are next!
131

131. ECG Quiz

132. EKG #1
1. What is the rhythm?
a. V-Tach
b. A-Fib
c. A-flutter
d. normal 133

133. EKG #2
1. What does this EKG represent?
a. pericarditis
b. myocarditis
c. digitalis effect
d. inferior wall ST-elevation MI
134

134. EKG #3
1. What is the rhythm?
a. V-Tach
b. A-Fib
c. A-flutter
d. normal 135

135. EKG #4
1. What does this EKG represent?
a. sius bradycardia
b. sinus tachycardia
c. 2nd degree AV block
d. complete heart block
136

136. EKG #5
1. What does this EKG represent?
a. V-fib
b. left bundle branch block
c. right bundle branch block
d. normal 137

137. EKG #6
1. What does this EKG represent?
a. V-fib
b. left bundle branch block
c. right bundle branch block
d. normal
138

138. EKG #7
1. What does this EKG represent?
a. V-fib
b. A-fib
c. Supraventricular tachycardia
d. normal
139

139. EKG #8
1. What does this EKG represent?
a. V-fib
b. A-fib
c. A-flutter
d. V- tach
140

140. EKG #9
1. What does this EKG represent?
a. V-fib
b. sinus bradycardia
c. complete heart block
d. sinus tachycardia 141

141. EKG #10
1. What does this EKG represent?
a. V-fib
b. left bundle branch block
c. right bundle branch block
d. normal
142

142. EKG #11
1. What diagnostic test would be the best to order next?
a. Echo
b. CTA
c. Cath 143

143. EKG #12
1. What therapy would be the best to order next?
a. Thrombolytic therapy
b. Emergent cath and PCI
c. Toradol IV 144

144. STEMI Alerts

145. Would You Activate the STEMI
Alert Team?
146

146. YES!
• This is an large anteroseptal, anterior,
and anterolateral MI
147

147. Would You Activate the STEMI
Alert Team?
148

148. NO!
• This is Pericarditis – inflammation of the
sac around the heart.
– Diffuse ST elevation
– PR segment depression
– Younger
– Recent viral syndrome
– Hurts worse with deep breaths or lying
down
149

149. Would You Activate the STEMI
Alert Team?
150

150. YES!
• This is new-onset Left Bundle Branch
Block
• Also note the lateral ST elevation
151

151. Would You Activate the STEMI
Alert Team?
152

152. Previous ECG (from 2011)
153

153. NO!
• This is a chronic Left Bundle Branch
Block
• Marker of CAD, heart valve disease, as
well as hypertension.
154

154. Would You Activate the STEMI
Alert Team?
155

155. NO!
• This is a PACED rhythm!
• No interpretation of the ECG is possible.
156

156. Would You Activate the STEMI
Alert Team?
157

157. NO!
• This is Early Repolarization.
– Early repolarization is a common ECG variant,
characterized by either terminal QRS slurring
(the transition from the QRS segment to the ST
segment) or notching (a positive deflection
inscribed on terminal QRS complex) associated
with concave upward ST-segment elevation
and prominent T waves in at least two
contiguous leads.
158

158. NO!
• This is Early Repolarization.
– This benign ECG phenomenon is noted in 1%
to 2% of the adult population and generally
occurs in the absence of myocardial disease.
– People with this mostly consist of men, young
adults, athletes, and people of African American
heritage
159

159. 160

160. 161

161. Would You Activate the STEMI
Alert Team?
162

162. YES!
• This is an inferior – posterior – lateral MI
163

163. Would You Activate the STEMI
Alert Team?
164

164. YES!
• This is Ventricular Tachycardia – and
likely is related to MI
165

165. Would You Activate the STEMI
Alert Team?
166

166. YES!
• This is an acute Anterior Wall MI with
Ventricular Bigeminy
167

167. Would You First Activate the
STEMI Alert Team?
168

168. NO!
• Shock that!
• While MI may be the reason for Vfib, other
reasons also need to be excluded.
• Consider Hypothermia Therapy in route
169

169. Section 5
170

170. Review of MHCA Protocols
• STEMI
• Stroke
171

171. Goals for STEMI
• First Medical Contact (FMC) to PCI < 90 minutes
• Door to ECG time < 10 minutes
• Door In / Door Out Time < 30 minutes
• FMC to Non-PCI hospital to PCI < 120 minutes
EMS specific
• Ideal for all chest pain patients to have in-field
ECG
• Pre-hospital Activation of STEMI network
• Diversion to STEMI hospital
172

172. EMS Requirements
Equip all ambulances in state with ECG machines by 2012
Ambulance services should obtain EKG within 15 minutes for
 typical chest pain in anyone > 30 years, and
 atypical chest pain in all patients 50 and older
 EMS should interpret and transfer ECG to affiliated ED
 EMS personnel need training / certification in ECG interpretation
of STEMI
173

173. ECG + Symptoms
• Chest pain,fullness, or
pressure
• Radiation to jaw, teeth,
shoulder, arm, or back
• Shortness of breath
• Epigastric discomfort
• Sweating
• Dizziness
• Cognitive impairment
174

174. EMS Requirements
 + EKG patients directly to PCI hospital if 90 minutes window
obtainable from first med contact to PCI AND patient is
hemodynamically stable
 + EKG patients directly to PCI hospital if 90 minutes window
obtainable from first med contact to PCI BUT patient is
hemodynamically UNSTABLE
 Go to nearest ED
 Activate Air Transport immediately for transfer to PCI center
175

175. EMS Requirements
 If no pre-hospital ECG available for a chest pain patient who
arrives at a non-PCI hospital
 Keep the patient on the EMS stretcher until ECG performed
 If EKG results + transfer to PCI hospital with SAME ambulance if
patient hemodynamically stable
176

176. STEMI Network (24/7) PCI Centers
Jackson
St. Dominic
MBHS
UMMC
CMMC
Hattiesburg
Forrest General Hospital
Wesley
Meridian
Jeff Anderson Hospital
Rush Hospital
Tupelo
North Mississippi Medical Center
Oxford
Baptist Memorial Hospital North
Mississippi
South Haven
Baptist Memorial Hospital Desoto
Corinth
Magnolia Regional Health Center
Vicksburg
River Region Hospital
Greenville
Delta Regional Medical Center
Columbus
Baptist Memorial Hospital Golden
Triangle
Pascagoula
Singing River Health Systems
Gulfport
Gulfport Memorial Hospital
McComb
South West Regional Medical
Center
177

177. EMS Territorial Boundaries Broken
 It is imperative for EMS to be able to cross county lines
when necessary for reperfusion.
 EMS services should cross-cover for adjacent EMS in
another county.
 A “Heart Attack” should take priority over many non-
life threatening medical conditions.
178

178. 179

179. Goals for STEMI
• First Medical Contact (FMC) to PCI < 90 minutes
• Door to ECG time < 10 minutes
• Door In / Door Out Time < 30 minutes
• FMC to Non-PCI hospital to PCI < 120 minutes
EMS specific
• Ideal for all chest pain patients to have in-field
ECG
• Pre-hospital Activation of STEMI network
• Diversion to STEMI hospital
180

180. Phases of EMS Management
of the Stroke Patient
• Activation of 911 system
• EMS response
• On scene assessment and stabilization
• Selection of appropriate destination
• Transport
• Pre-arrival stroke alert to receiving emergency
department (as early as possible)
• Delivery of patient and information
• PI feedback
181

181. Scene Assessment
• General assessment
– Consider alternative causes of neurologic deficit
• Focused neurologic assessment to include FAST
– Face
– Arm
– Speech
– Time
• Sensitivity 80%/specificity 30%
• Time of onset - may not be available at hospital
182

182. 183

183. Treatment
• Stabilization
– Standard protocols (check vital signs, ECG,
glucose, hydration and treat as needed)
– Scene time should be minimized but prehospital
care should not be sacrificed for less scene time
184

184. Select Appropriate Destination
• Transport to the nearest hospital with an
appropriate level of stroke care
– Level may vary as resources change
– Utilize knowledge of local facilities
• Window of opportunity – 4 ½ hours to
completion of fibrinolytic treatment (earlier
more effective than later)
• Useful time – 3 ½ hours until time of arrival at
stroke capable hospital
185

185. EMS Goals for Stroke
186

186. 1) Initial assessment, transport ASAP:
ABCs ; Obtain time of symptom onset (Last time known well) _______; Source of information
________; Contact information _________.
2) Administer high concentration oxygen, as needed, to maintain O2 Sat >94 percent.
3) Position patient with head/shoulders elevated to 15-30 degrees (unless contraindicated).
4) Maintain NPO.
5) Blood glucose < 60, treat per protocol.
6) Do not treat high blood pressure without physician approval.
7) Perform Stroke Scale – Cincinnati Stroke Scale.
8) Transport patient to the appropriate facility:
a. Transport patient to the closest hospital capable of treating the patient with IV Alteplase
(Stroke Capable or Primary/Comprehensive Stroke Center). Hospitals not able to diagnose
and treat stroke patients (Level 4 hospitals) may be by-passed. EMS may use discretion based
on transport time or other unforeseen factors.
b. Consider transport of the stroke patient with severe symptoms (hemiplegia, aphasia, neglect,
stably intubated) to a Comprehensive Stroke Center if symptom onset to hospital arrival time
is greater than 3 hours and less than 6 hours.
c. Transport patient to the closest appropriate facility if unstable (e.g., cardiac arrest, unstable
airway).
9) IV NS KVO once en route.
10) EKG once en route.
11) Notify receiving facility of estimated arrival time of acute stroke patient, Stroke Scale finding, and
time of onset. 187

187. Section 6
188

188. EMS Cardiac
Pharmacology
189

189. Oxygen
• Indications
– Any suspected cardiopulmonary emergency
– Saturate hemoglobin with oxygen
– Reduce anxiety & further damage
– Note: Pulse oximetry should be monitored
190

190. Oxygen
• Precautions
– Pulse oximetry inaccurate in:
• Low cardiac output
• Vasoconstriction
• Hypothermia
– NEVER rely on pulse oximetry!
– Too much oxygen can make some patients with
emphysema quit breathing
191

191. Aspirin
• Indications
– Administer to all patients with ACS, particularly
reperfusion candidates
• Give 325 mg as soon as possible, non-coated preferred
– Blocks formation of thromboxane A2, which
causes platelets to aggregate
192

192. Anti-Platelet Actions
193

193. Aspirin
• Precautions
– Many patients are allergic to aspirin – be sure to
ask!
– Does not provide blood thinning effects in all
people (aspirin resistance)
– Relatively contraindicated in patients with active
bleeding
194

194. Thienopyridines
(Brilinta, Effient,Plavix)
• Indications
– Use as a second anti-platelet agent in patients
with ACS, particularly reperfusion candidates
– Blocks ADP activation of platelets
– Usually given as a bolus dose
• Brilinta – 180 mg (MHCA preferred agent)
• Plavix (clopidogrel) – 600 mg
• Effient – 60 mg
195

195. Anti-Platelet Actions
196

196. Thienopyridine
• Precautions
– Plavix does not provide blood thinning effects in
all people (plavix resistance)
– Effient should not be given to patients with
previous stroke or TIA
– Relatively contraindicated in patients with active
bleeding
197

197. Glycoprotein IIb/IIIa Inhibitors
• Indications
– Inhibit the glycoprotein IIb/IIIa receptor in the
membrane of platelets, inhibiting platelet
aggregation
– Can be used as an early second anti-platelet agent
rather than thienopyridines, especially in those
who can’t swallow or have nausea and vomiting.
198

198. Anti-Platelet Actions
199

199. Glycoprotein IIb/IIIa Inhibitors
• Eptifibatide (integrilin)
– Within 10 minutes after bolus, > 90% of platelets
are inhibited
– Platelet function recovers within 4 to 8 hours after
discontinuation
– Dose
• 180 mcg/kg IV bolus, then 2 mcg/kg/min infusion
200

200. Glycoprotein IIb/IIIa Inhibitors
• Precautions
– Integrilin (eptifibatide) is a derivative of snake
venom
– Use in precaution in those patients with previous
snake bites
201

201. Heparin
• Indications
– Inhibits thrombin generation by factor Xa
inhibition and also inhibit thrombin indirectly by
formation of a complex with antithrombin III
– Exists in two forms
• Unfractionated
• Low molecular weight
202

202. Unfractionated Heparin
• Dosing
– Initial bolus 60 IU/kg
• Maximum bolus: 4000 IU
• Check efficacy of dose with ACT
• Not always effective
– Continuous infusion at 800-1200 units/hour
203

203. Low Molecular Weight Heparin
Lovenox (enoxaparin)
• Dosing in ACS in those proceeding to PCI or to
receive thrombolytics
– 30 mg IV
• Bolus is active for 3 hours
• Initial dosing in medically treated patients
– 1 mg/kg SQ
• Dose is active for 12 hours
204

204. Heparins
• Precautions
– Contraindications: active bleeding; recent
intracranial, intraspinal or eye surgery; severe
hypertension; bleeding disorders;
gastroinintestinal bleeding
– DO NOT use if platelet count is below 100 000
205

205. Nitroglycerin
• Indications
– Chest pain of suspected cardiac origin
– Unstable angina
– Complications of AMI, including congestive heart
failure, left ventricular failure
– Hypertensive crisis or urgency with chest pain
206

206. Nitroglycerin
• What it does…
– Decreases pain of ischemia
– Increases venous dilation
– Decreases venous blood return to heart
– Decreases preload and cardiac
oxygen consumption
– Dilates coronary arteries
– Increases cardiac collateral flow
207

207. Nitroglycerin
• What it does NOT do…
– Prevent heart attacks
– Save lives
– Limit infarct size
208

208. Nitroglycerin
• Dosing
– Sublingual Route
• 0.3 to 0.4 mg; repeat every 5 minutes
– Aerosol Spray
• Spray for 0.5 to 1.0 second at 5 minute intervals
– IV Infusion
• Infuse at 10 to 20 µg/min
• Route of choice for emergencies
• Titrate to effect
209

209. Nitroglycerin
• Precautions
– Use extreme caution if systolic BP <90 mm Hg
– Use extreme caution in Inferior and/or RV infarctions
– Suspect RV infarction with inferior ST changes
– Limit BP drop to 10% if patient is normotensive
– Limit BP drop to 30% if patient is hypertensive
– Watch for headache, drop in BP, syncope, tachycardia
– Tell patient to sit or lie down during administration
210

210. Morphine Sulfate
• Indications
– Chest pain and anxiety associated with AMI or
cardiac ischemia
– Acute cardiogenic pulmonary edema (if blood
pressure is adequate)
211

211. Morphine Sulfate
• Dosing
– 1 to 4 mg IV (over 1 to 5 minutes) every 5 to 10
minutes as needed
212

212. Morphine Sulfate
• Precautions
– Administer slowly and titrate to effect
– May compromise respiration; therefore use with
caution in acute pulmonary edema
– Causes hypotension in volume-depleted patients
213

213. Fibrinolytics
• Indications
– For AMI in adults
• ST elevation or new or presumably new LBBB; strongly
suspicious for injury
• Time of onset of symptoms < 12 hours
– For strokes in adelts
• Time of onset of symptoms< 4.5 hours
214

214. Fibrinolytics
• Dosing
– For fibrinolytic use, all patients should have 2
peripheral IV lines
• 1 line exclusively for fibrinolytic administration
215

215. Fibrinolytics
• Dosing for AMI Patients
– Tenecteplase (TNKase)
• Bolus 30 to 50 mg
– Alteplase, recombinant (tPA)
• Accelerated Infusion
– 15 mg IV bolus
– Then 0.75 mg/kg over the next 30 minutes
» Not to exceed 50 mg
– Then 0.5 mg/kg over the next 60 minutes
» Not to exceed 35 mg
216

216. Fibrinolytics
• Dosing for Acute Ischemic Stroke
– Alteplase, recombinant (tPA)
• Give 0.9 mg/kg (maximum 90 mg) infused over 60
minutes
– Give 10% of total dose as an initial IV bolus over 1 minute
– Give the remaining 90% over the next 60 minutes
– Alteplase is the only agent approved for use in
Ischemic Stroke patients
217

217. Fibrinolytics
• Precautions
– Specific Exclusion Criteria
• Active internal bleeding (except mensus) within 21 days
• History of CVA, intracranial, or intraspinal within 3
months
• Major trauma or serious injury within 14 days
• Aortic dissection
• Severe uncontrolled hypertension
218

218. Fibrinolytics
• Precautions
– Specific Exclusion Criteria
• Known bleeding disorders
• Prolonged CPR with evidence of thoracic trauma
• Lumbar puncture within 7 days
• Recent arterial puncture at noncompressible site
• During the first 24 hours of fibrinolytic therapy for
ischemic stroke, do not give aspirin or heparin
219

219. Amiodarone
• Indications
– Powerful anti-arrhythmic with activity in both
atria and ventricles; so that, this drug can be used
for atrial fibrillation and VT
– Can be used to prevent recurrent VF
220

220. Amiodarone
• Dosing
– 150 mg bolus dose
• May repeat x 1
– Can also use continual IV infusion
• 1 mg/min x 6 hours, then
• 0.5 mg/min
221

221. Amiodarone
• Precautions
– May produce vasodilation & hypotension
– May have negative inotropic effects
– Terminal elimination
• IV half-life lasts hours
• Oral half-life lasts up to 40 days
222

222. Lidocaine
• Indications
– VT
– Vfib
– Frequent PVCs
223

223. Lidocaine
• Bolus Dosing
– Initial dose: 1.0 to 1.5 mg/kg bolus IV
– May repeat bolus x 1 for refractory VF
– May also be given down ET tube
• Maintenance Infusion
– 2 to 4 mg/min IV continuous infusion
224

224. Lidocaine
• Precautions
– Reduce maintenance dose (not loading dose) in
presence of impaired liver function or left
ventricular dysfunction
– Discontinue infusion immediately if signs of
toxicity (seizures, confusion) develop
225

225. Atropine Sulfate
• Indications
– Should only be used for bradycardia
• Relative or Absolute
– Used to increase heart rate
226

226. Atropine Sulfate
• Dosing
– 1 mg IV push
– Repeat every 3 to 5 minutes
– May give via ET tube (2 to 2.5 mg) diluted in 10
mL of NS
227

227. Atropine Sulfate
• Precautions
– Increases myocardial oxygen demand
– May result in unwanted tachycardia or
dysrhythmia
– When given in low doses (<0.4 mg), can cause a
paradoxical bradycardia
228

228. Dopamine
• Indications
– Second drug for symptomatic bradycardia (after
atropine)
– Use for hypotension (systolic BP 70 to 100 mm Hg)
with S/S of shock
229

229. Dopamine
• Dosing
– IV Infusions (Titrate to Effect)
• Low Dose “Renal Dose"
– 1 to 5 µg/kg per minute
• Moderate Dose “Cardiac Dose"
– 5 to 10 µg/kg per minute
• High Dose “Vasopressor Dose"
– 10 to 20 µg/kg per minute
230

230. Dopamine
• Precautions
– May use in patients with hypovolemia but only after
volume replacement
– May cause tachyarrhythmias, excessive vasoconstriction
– DO NOT mix with sodium bicarbonate
231

231. Epinephrine
• Indications
– Increases:
• Heart rate
• Force of contraction
• Conduction velocity
– Peripheral vasoconstriction (raises blood pressure)
– Bronchial dilation
232

232. Epinephrine
• Dosing
– 1 mg IV push; may repeat every 3 to 5 minutes
– May use higher doses (0.2 mg/kg) if lower dose is
not effective
– Endotracheal Route
• 2.0 to 2.5 mg diluted in 10 mL normal saline
– Profound Bradycardia
• 2 to 10 µg/min infusion (add 1 mg of 1:1000 to 500 mL
normal saline; infuse at 1 to 5 mL/min)
233

233. Epinephrine
• Precautions
– Raising blood pressure and increasing heart rate
may cause myocardial ischemia, angina, and
increased myocardial oxygen demand
– Do not mix or give with alkaline solutions
– Higher doses have not improved outcome & may
cause myocardial dysfunction
234

234. Diltiazem
• Indications
– To control ventricular rate in atrial fibrillation and
atrial flutter
– Use after adenosine to treat refractory PSVT in
patients with narrow QRS complex and adequate
blood pressure
235

235. Diltiazem
• Dosing
– Acute Rate Control
• 10 to 20 mg (0.25 mg/kg) IV over 2 minutes
• May repeat in 15 minutes at 20 to 25 mg (0.35 mg/kg)
over 2 minutes
– Maintenance Infusion
• 5 to 15 mg/hour, titrated to heart rate
236

236. Diltiazem
• Precautions
– Do not use calcium channel blockers for tachycardias of
uncertain origin
– Avoid calcium channel blockers in patients with Wolff-
Parkinson-White syndrome, in patients with sick sinus
syndrome, or in patients with AV block without a
pacemaker
– Expect blood pressure drop resulting from peripheral
vasodilation
– Concurrent IV administration with IV ß-blockers can cause
severe hypotension or heart block
237

237. Question 1
• Which of the following is an adverse reaction
to nitroglycerin?
A) Hypertension
B) Hypotension
C) Lacrimation
D) Arrhythmias
238

238. Question 1
• Which of the following is an adverse reaction
to nitroglycerin?
A) Hypertension
B) Hypotension
C) Lacrimation
D) Arrhythmias
239

239. Question 2
• Which of the following must be given within
4.5 hours of the beginning of a stroke?
A. Thrombolytics
B. Anti-platelets
C. Heparin
240

240. Question 2
• Which of the following must be given within
4.5 hours of the beginning of a stroke?
A. Thrombolytics
B. Anti-platelets
C. Heparin
241

241. Question 3
• Which of the following agents is most
efficacious in the conversion of acute AF into
sinus rhythm?
a. Metoprolol
b. Digoxin
c. Amiodarone
d. Diltiazem
e. Esmolol
242

242. Question 3
• Which of the following agents is most
efficacious in the conversion of acute AF into
sinus rhythm?
a. Metoprolol
b. Digoxin
c. Amiodarone
d. Diltiazem
e. Esmolol
243

243. Question 4
• The following are true for aspirin, except:
a. Aspirin is indicated in combination with
warfarin in patients at high risk for mechanical
valve thrombosis
b. Clopidogrel should be administered to aspirin-
intolerant patients acutely with an STEMI
c. Aspirin is indicated in acute thrombotic stroke
d. Aspirin is FDA approved for primary
prevention of MI.
244

244. Question 4
• The following are true for aspirin, except:
a. Aspirin is indicated in combination with
warfarin in patients at high risk for mechanical
valve thrombosis
b. Clopidogrel should be administered to aspirin-
intolerant patients acutely with an STEMI
c. Aspirin is indicated in acute thrombotic stroke
d. Aspirin is FDA approved for primary
prevention of MI.
245

245. Question 5
• Appropriate upfront medical therapy in a
previously healthy 51 year old man having a
STEMI includes all of the following except:
a. Aspirin
b. Heparin
c. Lipitor
d. Brilinta
246

246. Question 5
• Appropriate upfront medical therapy in a
previously healthy 51 year old man having a
STEMI includes all of the following except:
a. Aspirin
b. Heparin
c. Lipitor
d. Brilinta
247

247. CONCLUSIONS
• Be constantly alert—patients can change in
seconds
• Know your drugs---use resources
• Remember that every drug, even OTC drugs,
have the potential to result in a serious
adverse reaction

248. CONCLUSIONS
• Never leave the sending facility unless you feel
thoroughly comfortable with your patient and
with the medications you are being asked to
administer or monitor

249. • Make sure that you are thoroughly prepared
for any complication
• Know where possible diversion hospitals are
located
• Use your EMS medical director whenever
necessary
CONCLUSIONS

250. Questions?

251. The End
• Thank you for your time today in learning the
interpretation of ECGs.
• With your new knowledge and proficiencies,
patients of Mississippi are in better hands.
252