to help making ECG easy

1. BY
Rizk Elazhary
MD, Anesthesiology
Benha University

2. Introduction

3. Anatomy of Cardiac Conduction System

4. Physiology of the heart

5. Electrocardiogram  Action potentials
through myocardium
during cardiac cycle
produces electric
currents than can be
measured
 Pattern
 P wave
 Atria depolarization
 QRS complex
 Ventricle depolarization
 Atria repolarization
 T wave:
 Ventricle repolarization

8. What is Arrhythmias?

9. Classification of Cardiac Arrhythmias
 Tachy arrhythmias(Fast).
 Brady arrhythmias(Slow).
 Regular-arrhythmias.
 Irregular-arrhythmias.
 Other arrhythmias.

10. Approach to Arrhythmias

11. The Six Step Approach
 What is the Rate?
 Is the Rhythm Regular?
 Are there P-Waves?
 Is the P-R Interval Normal?
 Is the QRS Complex Normal?
 Is There a P-Wave for Every QRS?

12. Normal Sinus Rhythm
 Rate: 60 - 100
 Regularity: Very
 P-Waves: Present and Normal
 P-R I: 0.12-0.20 sec
 QRS: 0.04-0.12 sec and Normal
 1 P: 1 QRS, no extras or shortages

13. Sinus Tachycardia
 Rate: Over 100
 Regularity: Regular
 P-Waves: Present and Normal
 P-R I: 0.12-0.20 sec
 QRS: 0.04-0.12 sec and Normal
 1 P: 1 QRS, no extras or shortages

14. Sinus Bradycardia
 Rate: Less than 60
 Regularity: Regular
 P-Waves: Present and Normal
 P-R I: 0.12-0.20 sec
 QRS: 0.04-0.12 sec and Normal
 1 P: 1 QRS, no extras or shortages

15. Atrial Fibrillation
 Rate: Usually tachy
 Regularity: Irregular (Irregularly irregular)
 P-Waves: Not Discernible
 P-R I: Undeterminable
 QRS: 0.04-0.12 sec
 P-QRS : Undeterminable

16. Atrial Flutter
 Rate: Usually tachy
 Regularity: Atria Regular
• Ventricles May be Irregular
 P-Waves: Saw tooth Pattern 2:1, 3:1, 4:1...
 P-R I: 0.12-0.20 sec on conducting beat
 QRS: 0.04-0.12 sec
 P-waves outnumber QRS

17. (Paroxysmal) Supra Ventricular Tach
 Rate: 140-220
 Regularity: Regular
 P-Waves: Usually falls within the QRS-T complex (
sometimes not visible)
 P-R I: Shorter than 0.12, or absent
 QRS: 0.04-0.12 sec and Normal
 P-QRS :Undeterminable

18. SVT
 WPW
 Usually based on Hx.
 Delta wave on Q
 Shortened PR-I
 No Verapamil – Accessory Path use increase

19. 1st Degree Heart Block
 Rate: 60 - 100
 Regularity: Very
 P-Waves: Present and Normal
 P-R I: Longer than 0.20 sec
 QRS: 0.04-0.12 sec and Normal
 1 P: 1 QRS, no extras or shortages

20. 2nd Degree Heart Block (Type 1) Wenkebach
 Rate: Can be Normal, or usually brady
 Regularity: Irregular
 P-Waves: Present and Normal
 P-R I: Lengthens until beat is dropped
 QRS: 0.04-0.12 sec and Normal
 P-wave present on conducting beats, increased delay
causes missed QRS

21. 2nd Degree Heart Block (Type 2) Mobitz II
 Rate: Less than 60
 Regularity: Irregular
 P-Waves: Present, 2:1, 3:1, 4:1
 P-R I: 0.12-0.20 sec on conducting beat
 QRS: 0.04-0.12 sec, may begin to widen
 P-wave for every QRS and extras depending on conduction
ratio

22. 3rd Degree Heart Block (CHB)Complete Heart Block
 Rate: Ventricular Rate 40-60
 Regularity: Atria-Regular
• Vent-Regular
 P-Waves: Present and Normal
 P-R I: Atria independent of Ventricles
 QRS: Usually greater than 0.12 sec
 P-waves completely unrelated to QRS Complexes.

23. Junctional Rhythm
 Rate: 40-60
 Regularity: Regular
 P-Waves: Inverted, Retrograde or Absent
 P-R I: Shortened or absent
 QRS: 0.04-0.12 sec
 P-wave for every QRS, sometimes not visible

24. Ventricular Tachycardia
 Rate: 100-220
 Regularity: Regular
 P-Waves: None
 P-R I: None
 QRS: Greater than 0.12 sec

25. Ventricular Fibrillation
 Rate: No ventricular rate
 Regularity: Irregular
 P-Waves: No
 P-R I: No
 QRS: No, unorganized ventricular baseline

26. Asystole
 Rate: 0
 Regularity: N/A
 P-Waves: None
 P-R I: N/A
 QRS: None
(check another lead)

27. Agonal / Idioventricular
 Rate: 20-40
 Regularity: Irregular
 P-Waves: None
 P-R I: N/A
 QRS: Wider than 0.12 sec
(a dying heart)

28. Other Arrhythmias
 Premature Ventricular Contractions
 Premature Atrial Contractions
 Bundle Branch Blocks
 Pacer Considerations (Atrial, Ventricular or Both)

29. Premature Ventricular Contractions
 Wide, Bizarre QRS Complex
 Always identify the underlying rhythm first
 Can appear in couplets, triplets, short runs of V-Tach,
bigeminy and trigeminy
 Can be uni-focal or multi-focal
 Caused by random firing within the ventricles
 Not accompanied by a P-wave

30. PAC’s
 P-QRS Complex appearing in an unexpected location
 Caused by a stimulus from within the Atria, but not from
the SA Node

31. Bundle Branch Block
 Any rhythm having a BBB will have a widened twin
peaked R-Wave

32. Bundle Branch Block

33. Paced Rhythms Various

34. QT Prolongation
 QT represents the ventricular refractory period
 Normal
 Men 450ms
 Women 460ms
 Corrected QT (QTc)
 QTm/√(R-R)
 Causes
 Drugs (Na channel blockers)
 Hypocalcemia, hypomagnesemia, hypokalemia
 Hypothermia
 AMI
 Congenital
 Increased ICP

35. Torsade de pointes
 Torsades de pointes is a polymorphic ventricular
tachycardia . The phrase “torsades de pointes” means
“twisting on a point” which explains the action of the QRS
complex and how it varies from beat to beat. It is a
shockable rhythm.

36. Normal Variants
 Always normal:
 Sinus Arrhythmia
 Supraventricular Extrasystoles
 Partial RBBB
 Often normal:
 Sinus Bradycardia (and pauses in athletes)
 First Degree Heart Block
 Ventricular Extrasystoles
 Left/Right Axis Deviation
 RBBB

37. Special Situations
 Dextrocardia – reverse precordial leads
 Large breasts – don't place electrodes on top of breast
 Bilateral breast implants you should apply V4, V5, and V6
close to the midaxillary line.
 Note patient abnormalities on ECG
 Do not place electrodes on open wounds, burns, or clear
dressings
 Do not allow electrodes to touch one another

38. References
 Pictures and info from:
 Flip and See ECG, 2nd Edition
 Cohn/Gilroy-Doohan
 A great resource
 Paramedic Paramedic Textbook, Revised 2nd Edition
 Mick J. Sanders, Mosby
 ECG’s Made Easy, 2nd Edition
 Barbara Aehlert, RN, Mosby
 Basic Dysrhythmias, Interpretation and Management,
3rd Edition
 Robert J. Huszar, Mosby