ECG BASICS 1ST Lecture Introduction and P waves Dr Salah Mabrouk Khalaf pulmonale mitrale f waves F waves inverted p wave multiple shaped in same lead

1. ECG BASICSECG BASICS
11STST
LectureLecture
Introduction and P wavesIntroduction and P waves
By
Salah Mabruok Khalaf
South Egypt Cancer Institute
2017
Course of Medical Oncology
Medical Oncology department

2. • Introduction
• P wave

3. • The standard 12-lead electrocardiogram is a
representation of the heart's electrical activity
recorded from electrodes on the body surface.

4. • Like football match:
 Ball ----------→ impulse
 Cameras -----→ Leads
 playground ------ → pathway
of conduction
 TV screen ---→ ECG paper

5. • If impulse direction towards the lead
• Positive wave
• If impulse direction away from the lead
• Negative wave
Golden Rule

6. How do you apply this Rule?
• To apply this rule, remember
impulse direction and recording lead

7. Impulse direction
Normal Impulse Conduction
Sinoatrial node
AV node
Bundle of His
Bundle Branches
Purkinje fibers

8. The “PQRST”
• P wave - Atrial
depolarization
• T wave - Ventricular
repolarization
• QRS - Ventricular
depolarization

9. Recording leads
• Chest leads

10. They are placed on the body as follows:
V1 on the 4 th intercostal space, to the right of the sternum.
V2 on the 4 th intercostal space, to the left of the sternum.
V3 in-between V2 and V4.
V4 on the 5 th intercostal space in the midclavicular line (the
apex beat).
V5 in 5 th intercostal space in anterior axillary line
V6 5 th intercostal space in the midaxillary line,

11. Limb leads
• How to apply on the patient:
• Green lead-------left leg
• Yellow lead-----left wrist
• Red lead ------right wrist
• Black lead -----right leg

12. III
AvF
AvR
AvL
I
II

14. The 12-Lead ECG Format

15. The ECG Paper
• Horizontally
– One small box - 0.04 s
– One large box - 0.20 s
• Vertically
– One large box - 0.5 mV

17. • each small box is .04 seconds.
• Two small boxes would equal .08 seconds
• four small boxes equals .16 seconds
• five small boxes, which is one large box, equals .20
seconds

18. • The time lines in the top border of the paper.
The distance from one time line to the next is
three seconds.

19. Comment on ECG(10)
1. Rate
2. Rhythm
3. Axis
4. P wave
5. QRS complex
6. T wave
7. PR interval
8. ST segment
9. QT interval
10. Other
Conclusion (Diagnosis)

20. • Formation: Atrial depolarization
• Golden rule :
1-Rt atrium:
• SA node
• AV node
P wave
II
III
AvF
AvR
I
AvL
+ wave

21. P wave
• Formation: Atrial depolarization
• Golden rule :
1-Lt atrium:
• septum
• wall
IIIII
AvF
AvR
I
AvL
To the baseline

22. P wave
Lead II AvR
Rt atrium
Lt atrium
Total
Rt Lt Rt Lt

23. Normal P wave
• +ve in lead II
• – ve in AvR
• 2.5 x 2.5 ss
II
AvR

24. 1- P pulmonale : Rt atrial hypertrophy
Abnormal P wave
II
Increase amplitude = tall > 2.5 ss

25. 1- P pulmonale : Rt atrial hypertrophy
Abnormal P wave

26. 2- P mitrale : Lt atrial hypertrophy
Increase duration = width > 2.5 ss
Sometimes bifid
Always increased width
Abnormal P wave
II
+ wave

27. 2- P mitrale : Lt atrial hypertrophy
Abnormal P wave

28. 3- Replaced by f waves= fibrillation waves
In atrial fibrilation (AF) in which each muscle
fibrillate separately
Abnormal P wave
II
Irregular …..Why?
When become regular

29. 3- Replaced by f waves= fibrillation waves
Abnormal P wave

30. 4- Replaced by F waves
In atrial Flutter
Impulse from SA node with rapid rate =150-
300/m
AV node block some
of these to prevent
Vent. Tachy.
Abnormal P wave
II
P P P P P P
TT

31. 4- Replaced by F waves: atrial flutter
Abnormal P wave

32. Atypical atrial flutter
Atypical atrial flutter with irregular RR intervals due to variable
atrioventricular conduction.

33. Atrial fibrillation vs Flutter

34. 5- inverted P wave in lead II (+ve in AvR)
In impulse away from lead II i.e from AV node
II
-ve wave
P

35. P
P
NO P
Conditions of AV nodal impulse
1-AVN give atrium before ventricle
Inverted P wave then QRS
2-AVN give ventricle before atrium
QRS then Inverted P wave QRS
3-AVN give atrium and ventricle at same time
P wave masked in QRS( absent P)
av
II

36. Inverted P wave
in premature junctional conduction (JPB)

37. Inverted P wave
in junctional rhythm

38. 6- Absent P (see arrhythmia)
Masked in QRS
When atria depolarize with
ventricles
No atrial depolarization
AvN ectopy Ventr. ectopy SAN arrest SAN block

39. Premature ventricular contraction

40. 7- Distorted P wave
In case of atrial ectopic:
1- distorted P wave.
2- premature
3- normal QRS-T
4- incomplete
compensatory pause

41. Atrial vs vent. ectopic

42. 8-Different shapes in same leads (II)
In multifocal atrial ectopics:
1- distorted P wave.
2- premature
3- normal QRS-T
4- incomplete
compensatory pause
5- multiple ectopics with different P shapes in
between sinus waves

43. Multifocal atrial ectopics