1. ECG
Dr. Mohammed Shaat Modified by : Dr. Amal Al Maqadma.

2. Electrocardiography
It is a voltage difference, record the electrical activity of the heart as well as valuable information about the heart function and structure.
Willem Einthoven 1924

3. Leads (lead x electrode)
LIMB LEADS I II
III
AVF
AVL
AVR
CHEST LEADS V1 V2 V3 V4 V5 V6
bipolar
unipolar

4. Limb leads

5. Limb leads

6. Both limb leads

7. Chest leads

8. What chest lead represent ?

9. ECG Leads - Views of the Heart
V1 & V Septum
V3 & V anterior +Right Ventricle
V5 & V Lateral Left Ventricle
II+III+AVF inferior border

10. : einthoven's triangle

13. ECG Paper
ECG Speed 25mm/sec

14. 12 lead ECG layout:

15. See video

17. ECG Cardiac Cycle

19. What is the isoelectric line؟

20. P wave
Represent the electrical activity of both atria ( atrial depolarization)
The depolarization slow within the AV node, there is a brief delay or PAUSE before the depolarization conducted to the ventricles

21. Normal duration <0.12 sec Absent P wave: Atrial fibrillation SA Block AV Rhythm Peak P wave: Atrial hypertrophy

22. PR interval Normally :0.12-0.2sec Prolonged in : heart block.
Short in : W-P-W syndrome.

23. QRS Complex Represent the electrical activity of both ventricles.
Ventricular depolarization( initiation of the ventricular contraction

24. QRS Complex Q wave R wave: S wave :
: Normal QRS duration < 0.12 sec

25. QRS Complex Q wave first downward deflection . septal depolarization.
0.04sec.

26. R wave: first upward deflection.
height: 5-8 mm.
early ventricular depolarization

28. S wave : late ventricular depolarization,

29. Large QRS indicate Ventricular hypertrophy.

30. ST - Segment
ST segment: the plateau phase of ventricular repolarization.
Isoelectric or> or<1mm.
If the ST segment elevated or depressed beyond the normal baseline this usually sign of serious pathology. (MI)

31. T- Wave T-wave :represent rapid phase of ventricular repolarization.
peaked T wave:
early MI
hyperkalemia
Black races
Inverted :
MI .
Ventricular hypertrophy.
Hypokalemia
Digoxin

32. Q-T interval 0.4 sec in HR 70 Prolonged in : Hypocalcemia
hypomagnesemia

33. U wave repolarization of the interventricular septum. low amplitude
Prominent: suspect hypokalemia, hypercalcemia or hyperthyroidism

34. J wave
represents the approximate end of depolarization and the beginning of repolarization
camel-hump sign .
Hypothermia
hypocalcemia.

35. Low voltage ECG
Obesity
Emphysema
COPD
Severe hypothyroidism

36. Rate Normal heart rate 60-100/ min < 60 called bradycardia
>100 called tachycardia

37. How To Calculate Heart Rate ?

39. 300
No. of Large box btw R-R
HR=
1500
No. of Small box btw R-R
HR=

41. RHYTHM Look For The Distance between Identical waves.
Most commonly used R-R

44. AXIS
At any point during depolarization and repolarization electrical potential are being propagated in different directions. Most of these cancel each other out and only the net force is recorded. This net is called AXIS or cardiac VECTOR

46. How To Check Axis in ECG

48. THANKS