2. ECG
Ischemia Injury infarction
Dr. UZMA ANSARI
2
Using ECG one can localize the site of Ischemia / Injury/ Infarction.
Chief diagnostic tool to identify
26-Jul-23
4. Anatomy Of heart
Upper Left
Right
Inferior
Surface
Anterior
left
Inferior
Base
26-Jul-23
Dr. UZMA ANSARI
4
Apex – Left Ventricle
Borders
5. SURFACES OF HEART
Anterior: Right
atrium, Right
ventricle partly by
LV,LA.
LEFT: LV,LEFT
AURICLE
Inferior/Diaphragmatic:
2/3 by LV&1/3 by RV.
26-Jul-23
Dr. UZMA ANSARI
5
8. Anatomy of Left
ventricle
Dr. UZMA ANSARI
8
• Central left part
of thorax (lying
on diaphragm)
• Oriented
anteriorly with
apex directed
forward from
right to left
Location
Cone Shaped
4 wall
Septal
Anterior
Lateral
Inferior
Apex
According to new terminology infero
posterior should be called infero basal
- Source: AHA
26-Jul-23
Base/posterior surfase
9. Blood supply
RCA
Smaller
Ant aortic sinus
RA
RV except area around
anterior I V groove
Posterior I V Septum
LV:small area around
posterior IV groove
Entire conducting
system
LCA
Larger
Lt post aortic sinus
LA
LV except area
around posterior IV
groove
Anterior I V septum
RV:small area
around anterior IV
groove
Part of LBB
26-Jul-23
Dr. UZMA ANSARI
9
11. LMCA Entire LV, LA, except the posterior portion of IV septal
and adjacent area when PD is a branch of RCA
LAD • Anterior 2/3rd of IV septal
• Anterior portion of LV
• Whole apex
1st D (Branch of
LCA)
High lateral wall of LV
2nd D Lower lateral aspect of LV freewall
1st Septal Superior and Anterior portion of IV septal
Minor Septal Inferior and anterior 1/3rd of septum
Ramus Inter
ventricularis (From
LCA)
Anterior aspect of apex
Dr. UZMA ANSARI
11 26-Jul-23
12. LCX • 97% from LCA
• 2% from Separate Ostium
• 1% RCA
Obtuse margin of heart
and entire posterior
wall. LA, posterior IV
septum if PD arises
from LCX
OM • 97% LCA Obtuse margin of heart
adjacent to LV
Postero lateral
branch
• 80% LCA
• 20% RCA
Posterior and
diaphragm LV wall
PD • 82% RCA
• 18% LCA
Posterior IV septum
and Diaphragm LV
Dr. UZMA ANSARI
12 26-Jul-23
13. RCA RA and part of LA, RV,
Posterio superior IV septum.
SN, AV node
Acute Marginal Inferior and diaphragmatic
surface of RV
Conus Branch Outflow track of RV
SN branch RA, LA,SN
RV Branch RV
Atrial Branch Right Atrium
Dr. UZMA ANSARI
13 26-Jul-23
14. Localization - Left Coronary Artery (LCA)
Left Main
(proximal
LCA)
occlusion
• Extensive
Anterior injury
Left
Circumflex
(LCX)
occlusion
• Lateral injury
Left Anterior
Descending
(LAD)
occlusion
• Anteroseptal
injury
Dr. UZMA ANSARI
14 26-Jul-23January 2004
15. Localization
Right Coronary Artery (RCA)
Dr. UZMA ANSARI
15
Proximal
RCA
occlusion
• Right Ventricle injured
• Posterior wall of left ventricle injured
• Inferior wall of left ventricle injured
Posterior
descending
artery
(PDA)
occlusion
• Inferior wall of left ventricle injured
26-Jul-23January 2004
16. Localization Summary
Dr. UZMA ANSARI
16
Left Coronary Artery
Septal
Anterior
Lateral
Possibly Inferior
Right Coronary Artery
Right Ventricular Infarct
Inferior
Posterior
26-Jul-23January 2004
17. Prevalence of Culprit Artery
RCA 45%
LCX 12%
LAD 36%
Dr. UZMA ANSARI
17
57%
26-Jul-23
19. Post Ischemic T wave changes
ST elevation MI Non-ST Elevation
Infarction
Dr. UZMA ANSARI
19
ST depression, peaked T-
waves, then T-wave
inversion
ST elevation &
appearance of Q-waves
ST segments and T-waves
return to normal, but Q-
waves persist
Ischemia
Infarction
Fibrosis
ST depression &
T-wave inversion
ST depression &
T-wave inversion
ST returns to
baseline, but T-
wave inversion
persists
Infarction
Fibrosis
Ischemia
26-Jul-23January 2004
20. Localization
Dr. UZMA ANSARI
20
I Lateral
II Inferior
III Inferior
aVR
aVL Lateral
V1 Septal
aVF Inferior
V2 Septal
V3 Anterior
V4 Anterior
V5 Lateral
V6 Lateral
26-Jul-23January 2004
The changes of ischemia/injury/infarction are seen in the leads
Over lying the area involved
21. Localization
Dr. UZMA ANSARI
21
Inferior: II, III, AVF
Septal: V1, V2
Anterior: V3, V4
Lateral: I, AVL, V5, V6
I
II
III
aVR
aVL
aVF
V1
V2
V3
V4
V5
V6
26-Jul-23January 2004
22. Frontal Plane Leads
Dr. UZMA ANSARI
22
aVL
-300
I
II
III
00
aVF
-aVR
+900
+600
+1200
-1500
300
26-Jul-23
24. Localization - Myocardial Infarct
Localization ST elevation
Reciprocal
ST depression
Coronary Artery
Anterior MI V1-V6 None LAD
Septal Mi
V1-V4,
disappearance of
septum Q in leads
V5,V6
none LAD
Lateral MI I, aVL, V5, V6 II,III, aVF (inferior leads) LCX
Inferior MI II, III, aVF I, aVL (lateral lead)
RCA (80%) or LCX
(20%)
Posterior MI V7, V8, V9
high R in V1-V3 with ST
depression V1-V3 > 2mm
(mirror view)
RCA or LCX
Right Ventricle MI V1, V4R I, aVL RCA
Atrial MI PTa in I,V5,V6 PTa in I,II, or III RCA
Dr. UZMA ANSARI
24
The localisation of the occlusion can be adequately visualized using a
coronary angiogram (CAG).
26-Jul-23
25. Anterior Wall
V3,
V4
• Left anterior
chest
• Positive
electrode on
anterior chest
Dr. UZMA ANSARI
25
I
II
III
aVR
aVL
aVF
V1
V2
V3
V4
V5
V6
26-Jul-23
27. Septal Wall
V1, V2
◦ Along sternal borders
◦ Look through right ventricle & see septal
wall
I
II
III
aVR
aVL
aVF
V1
V2
V3
V4
V5
V6
Dr. UZMA ANSARI
27 26-Jul-23
28. Practice 2
Dr. UZMA ANSARI
28
Anteroseptal MI
ST elevations V1, V2, V3, V4
26-Jul-23January 2004
29. Dr. UZMA ANSARI
29
Lateral Wall
I and aVL
◦ View from Left Arm
◦ lateral wall of left ventricle
I
II
III
aVR
aVL
aVF
V1
V2
V3
V4
V5
V6
26-Jul-23January 2004
30. Lateral Wall
V5 and V6
◦ Left lateral chest
◦ lateral wall of left ventricle
I
II
III
aVR
aVL
aVF
V1
V2
V3
V4
V5
V6
Dr. UZMA ANSARI
30 26-Jul-23
33. Localization - Extensive Anterior MI
Dr. UZMA ANSARI
33
Evidence in
septal, anterior,
and lateral leads
Often from
proximal LCA
lesion
Complications
common
• Left ventricular failure
• CHF / Pulmonary
Edema
• Cardiogenic Shock
26-Jul-23January 2004
34. Practice 1
Dr. UZMA ANSARI
34
Anterior MI with lateral
involvement
ST elevations V2, V3, V4
ST elevations II, AVL, V5
26-Jul-23January 2004
35. Dr. UZMA ANSARI
35
Inferior Wall
II, III, aVF
◦ View from Left Leg
◦ inferior wall of left ventricle
I
II
III
aVR
aVL
aVF
V1
V2
V3
V4
V5
V6
26-Jul-23
37. Practice 3
Dr. UZMA ANSARI
37
Inferior MI
ST elevation 2,3 AVF
26-Jul-23January 2004
38. Practice 4
Dr. UZMA ANSARI
38
Inferior lateral MI
ST elevations 2, 3, AVF
ST elevations V5
26-Jul-23January 2004
39. Posterior Leads
Posterior leads V1, V2
Posterior Infarct with ST
Depressions and/ tall R wave
RCA and/or LCX Artery
ST elevation in V7,V8,V9.
Understand Reciprocal changes
The posterior aspect of the heart is
viewed as a mirror image and
therefore depressions versus
elevations indicate MI
Rarely by itself usually in combo.
Dr. UZMA ANSARI
39 26-Jul-23January 2004
42. Anterior wall MI
Occlusion of LAD
ST , V1-V6
Occlusion above D1 and 1st Septal
Basal portion of LV
Anterior and lateral wall
Inter-Ventricular Septum
ST segment vector – superiorly and to left
Dr. UZMA ANSARI
42
ST elevation ST depression
V1-V4, lead I, aVL, often in
aVR
II, III, aVF (Inferior) often V5
aVL > aVR III > II
26-Jul-23January 2004
43. Occlusion: Between 1st Septal and D1
Basal IV septum spared
(ST segment in lead V1 will
not be elevated)
ST segment vector
directed towards aVL
• ST segment elevation : aVL
• ST segment depression: III
Dr. UZMA ANSARI
43 26-Jul-23January 2004
44. Occlusion: More distally i.e.
below Septal 1 and D1
Basal portion spared (ST vector directed inferiorly)
ST segment not elevated in I, aVL/aVR
No depression in II, III, aVF
Indeed, ST segment elevation in II, III, aVF
ST segment elevation more prominent in V3 – V6
than V2
Dr. UZMA ANSARI
44 26-Jul-23January 2004
47. Recommendation
I, aVL, V1-V4 – Extensive
anterior wall infarction due to
occlusion of proximal LAD
V3 – V6, II, III aVF – AWMI
due to mid / distal occlusion
of LAD
Dr. UZMA ANSARI
47 26-Jul-23January 2004
48. Inferior MI
ST Elevation in II,III,aVF
RCA OR LCX
ST III>II ST II>III
ST I,aVL ST I,aVL
26-Jul-23January 2004
Dr. UZMA ANSARI
48
Whichever provides PD –
Dominant artery
50. Proximal RCA
Dr. UZMA ANSARI
50
Right Ventricular
Ischemia / Infarction
ST vector directed towards
right and anteriorly inferiorly
ST elevation in right
anterior leads i.e. V3R,
V4R, sometimes V1
40% Associated with
inferior M.I.ST elevation-
V3R,V4R,V1,II,III,aVF
V4R
1. Most commonly used right sided lead
2. Great value in diagnosing RV infarct
along with IWMI
3. Useful in distinguishing between RCA
and LCX involvement
4. Between proximal and distal RCA
occlusion
5. V3R, V4R should be recorded as
rapidly as possible because ST
elevation in V3R, V4R remain for a
shorter period of time in RWMI than
ST elevation in extremity leads (II,III,
aVF) in inferior MI
26-Jul-23January 2004
51. Inferior MI +Posterior M.I.
Lateral / Infero Lateral / Baso Lateral MI not postero inferior
MI.
Proximal RCA OR LCX
(posterior+inferior) Posterior+Inferior MI
+ RV infarct
ST II,III,aVF,aVL,I
ST II,III,aVF ST ,tall R V1,V2,V3,
ST I,aVL ST II>III
ST V3R,V4R
ST III>II
Dr. UZMA ANSARI
51 26-Jul-23January 2004
54. Multiple Ischemia / Infarction / Injury
Dr. UZMA ANSARI
54
ST depression in multiple
leads in absence of
elevation
Subendocardial ischemia
/ injury at multiple region
due to multi vessel
disease
2 Situations
During treadmill test
Stable angina
Multiple vessel
involved
At Rest
Unstable angina
Severe multi vessel
disease or LMCA
involvement
ST depression in more than / equal to 8 leads along with ST elevation in aVR and / or
V1Indicates 75% chances of 3 vessel disease / LMCA stenosis
Source: AHA
26-Jul-23January 2004
55. In some cases, Deep T wave ( > 0.5 mV ) in V2, V3, V4
with prolong QT after an episode of chest pain without
evidence of Ischemia / Injury / Infarction
(i.e. T wave morphology similar to CVA)
Dr. UZMA ANSARI
55
CAG
Severe stenosis of proximal LAD
If missed and not treated,
it could lead to AWMI
So, If we get deeply inverted T wave (> 0.5 mV) with prolonged QT,
one should suspect Severe stenosis of proximal LAD with / without CVA
Appropriate treatment
26-Jul-23January 2004
