explain ECG

1. Action potential
“AP”
Electrocardiograph
“ECG”
Hamad Emad Dhuhayr

2. CONTENTS
1. SOEPEL
2. AP
3. ECG

3. SUBJECT:
Presenting Complaint
An 81 year-old Saudi male is admitting to hospital with worsening abdominal pain over
the last 2-3 days.
There is no chest pain or dsyponea (shortness of breath), however she complains
of nausea and vomiting.
Past Medical History
On examination of the patient's history it appears that he has a history of
hypertension,Type 2 Diabetes mellitus (formerly NIDDM), coronary artery
disease status post myocardial infarction (CAD S/P MI) 5 years ago and chronic
abdominal pain for the last 2 years without a clear reason.
SOEPEL

4. OBJECTIVE:
taking history, physical examination
VITAL SIGNS:
*Physical Examination
38.8 C
RR: 16/min
78 bpm
210/100 mm/Hg
SOEPEL

5. EVALUATION (DD):
Myocardiac infraction
Appendicitis
Peptic ulcer
PLAN: ECG , ckmp and troponin *i-t* blood test.
ELABORATION: surgical intervention
SOEPEL

6. LEARNING GOALS:
AP - ECG
SOEPEL

7. AP

11. Localization - Myocardial Infarct
Localization ST elevation
Reciprocal
ST depression
Coronary Artery
Anterior MI V1-V6 None LAD
Septal Mi
V1-V4, disappearance
of septumQ 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 inV1-V3 with ST
depressionV1-V3 > 2mm
(mirror view)
RCA or LCX
RightVentricle MI V1,V4R I, aVL RCA
Atrial MI PTa in I,V5,V6 PTa in I,II, or III RCA
11
The localisation of the occlusion can be adequately visualized using
a coronary angiogram (CAG).

12. AnteriorWall
V3,
V4
• Left anterior chest
• Positive electrode
on anterior chest
12
I
II
III
aVR
aVL
aVF
V1
V2
V3
V4
V5
V6
24-May-14

13. 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
1324-May-14

14. Practice
14
Anteroseptal MI
ST elevations V1, V2, V3, V4 24-May-
14January 2004

15. 15
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
24-May-
14January 2004

16. 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
1624-May-14

17. LateralWall
• I, aVL,V5,V6
• ST elevation suspect lateral wall injury
17
Lateral Wall
24-May-14

18. Lateral MI
1824-May-14

19. 19
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
24-May-14

20. Inferior MI
2024-May-14

21. Posterior Leads
• Posterior leadsV1,V2
• Posterior Infarct with ST
Depressions and/ tall R wave
• RCA and/or LCXArtery
ST elevation inV7,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 21
24-May-
14January 2004

22. 24-May-14Dr. UZMA ANSARI 22

25. ECG 1.The ECG above belongs to a patient with stable angina pectoris.The patient complained of effort angina
in the last 2
weeks. Coronary angiography was performed and then the patient was referred to coronary artery bypass graft
operation
because of 3 vessel disease. ST segment flattening is one of the first signs of coronary ischemia and generally
preceedes ST
segment depression.