1. Dr. Amal Al Maqadma Teaching assistant IUG
ECG
Dr. Amal Al Maqadma
Teaching assistant
IUG

2. MI Ischemia ( subendocardial or transmural) Injury
When myocardial blood supply is abruptly reduced to
a region of the heart, a sequence of injurious events
occur :
Ischemia ( subendocardial or transmural)
Injury
Necrosis, and eventual fibrosis (scarring) if the blood supply isn't restored in an appropriate period of time

4. Hyperacute T wave is the earliest sign of acute myocardial infarction

5. Precordial Septal Leads
V1 – V2
– Look at the Septum of the heart
– The septal branch of the LAD

6. Precordial Anterior Leads
V3 – V4
–anterior wall of the left ventricle
–The LAD diagonal branch)

7. Anterior-Septal Terminology

8. Lateral Precordial Leads
I,AVL,V5 – V6
lateral of the left ventricle
The left circumflex

9. Inferior border leads II, III and aVF the Inferior wall of the RV
Posterior Descending Branch of the RCA.

10. Posterior MI No leads look at the posterior wall.
usually associated with inferior and/or lateral wall MI.
The changes of posterior myocardial infarction are seen indirectly in the anterior precordial leads. Leads V1 to V3 face the endocardial surface of the posterior wall of the left ventricle. As these leads record from the opposite side of the heart instead of directly over the infarct, the changes of posterior infarction are reversed in these leads. The R waves increase in size, becoming broader and dominant, and are associated with ST depression and upright T waves. This contrasts with the Q waves, ST segment elevation, and T wave inversion seen in acute anterior myocardial infarction.
ST depression is considered reciprocal ECG changes in what should be ST elevation for acute posterior wall injury.

11. ECG Leads - Views of the Heart
Arterial supply
border
lead
RCA
anterior Right Ventricle
V3 & V4
LAD
Septum
V1 & V2
LCX
Lateral Left Ventricle
a VL,V5 & V6
inferior borderof right ventricle
II+III+AVF

12. Principles of ECG recording
Explain the indication and the procedure for the patient. (assurance )
Ask the patient to take off any metals he/she wears.
Expose the wanted sites.
Cleaning of skin and shaving if necessary.
Place the electrodes in the correct positions .
Instruct the patient to remain still (should not talk during the test ) and relax their shoulders and legs while the recording takes place (1 min)

13. See video

14. How to comment on ECG Name.Age ,Date and time.
Calibration and Speed of paper
RAWIHI :

15. RAWIHI R: rate, regularity,rhythm(sinus or asinus), A: axis. W:waves.
I :intervals.
H: hypertrophy.
I: ischemia

16. Normal Sinus Rhythm Rate = 60-100 beat / minute. The rhythm is regular
All intervals are within normal limits
There is a P for every QRS and a QRS for every P.
P : QRS ratio = 1 : 1.
The P waves all look the same
Presence of P, QRS, T in each cycle.
Normal shape, time of waves, segments and intervals

17. Interfering factors Inaccurate placement of the electrodes
Electrolyte imbalances
Poor contact between the skin and the electrodes
Movement or muscle twitching during the test
Drugs that can affect results include digitalis, quinidine, and barbiturates