1. EKG Recognition for EMT’s (Part 2)
Scott S. Shadoin EMT-P
Boca Raton Fire Rescue
Boca Raton, Fl
Emergency Medical Consultants
Port St. Lucie, Fl

2. Professional Disclosures
None

3. Objectives Discuss the anatomy of the heart
Understand the components of an ECG
Understand the following ECG’s
Ventricular Rhythms
AV Heart Blocks
Pacemaker Rhythms

4. Cardiac Anatomy Myocardium Muscle of the heart
Should contract when stimulated
Atria
Upper chambers of the heart
Ventricles
Lower chambers of the heart

5. Cardiac Anatomy Septum
Separates left and right sides of atria and ventricles
Cardiac Skeleton
Separates the atria from the ventricles
Impermeable to electricity
Electrical conduction system
Pathways through the heart for electricity

6. Electrical Conduction System
Electricity created in Sinoatrial Node travels through electrical system
Myocardium contracts in response to stimulation
Depolarization
Change in cells electrical potential
Muscle contracts in response
Repolarization
Cell resets to original electrical potential
Muscle is relaxed

7. Electrical Conduction System

8. Electrical Conduction System

9. Electrical Conduction System
Sinoatrial Node (SA Node)
Pacemaker of the heart
Sends electricity into atrium
Bachmann’s Bundle (intra-atrial pathway)
Delivers electricity to left atrium
Atrioventricular node (AV Node)
“Doorway” to ventricles
Pauses electrical flow

10. Electrical Conduction System

11. Electrical Conduction System
Bundle of His
Splits in L/R bundle branches
Connects AV node to Purkinje fibers
Bundle branches
Travel through ventricular septum
Left bundle splits into anterior/posterior fascicle
Purkinje fibers
Disseminate electricity through the ventricles

12. Electrical Conduction System

14. EKG Paper Left to right = TIME -Small box = .04 sec
-Large box = .20 sec
-3 second ticks/marks
Up/down = DIRECTION
-Up = Positive
-Down = Negative
Height = VOLTAGE
-10 small boxes = 1mV

15. ECG Components P wave First part of the ECG complex
Atrial depolarization
QRS
Usually largest voltage
Ventricular depolarization
T Wave
Ventricular repolarization

16. ECG Pieces P waves Round (ish) Upright
<.12 sec (3 small boxes wide)
<.25 mv (2 ½ small boxes high)

17. ECG Pieces
Q wave
If it occurs, first negative deflection after the P wave
Septal depolarization
< .04 sec (1 box wide)
< 1/3 total height of QRS

18. ECG Pieces R wave First positive deflection after the P wave
Usually largest voltage on ECG
Beginning phase of ventricular depolarization
Entire QRS sec (1 to 3 small boxes)

19. ECG Pieces S wave Return to baseline after R wave
May be small or not present
Late or ending of ventricular depolarization

20. ECG Pieces T wave Positive (usually) deflection after the QRS
Ventricular repolarization

21. Electrode placement Lead I Lead 2 Lead 3 From Right arm to Left arm
From Right arm to Left leg
Lead 3
From Left arm to Left leg
*Lead 2 is the typical monitoring lead

22. ECG Rules What is the rate? Is it regular? How do the P waves look?
PR Interval?
QRS width?
Interpretation?
Clinical Significance?

23. Rate? Ventricular Rate R to R 6 second rule
Number of R waves in 6 seconds x10
Triplicate method
# of large boxes (5 small boxes) between R waves, divide into 300
1 box = 300, 2 box = 150, 3 box =100, etc

24. Regular? Measure distances from R to R
Can be slightly irregular with breathing, etc

25. P waves and PR Interval? Should be upright Consistent in shape
QRS Relationship
From start of P wave to QRS <.20 sec (5 small boxes)
P in front of every QRS (consistent PR interval)
QRS after every P wave

26. QRS width? Narrow < .10 probably supraventricular (2 ½ small boxes)
Wide
>.12 Probably ventricular (3 small boxes)

27. Ventricular Rhythms

28. Ventricular Tachycardia
Rate?
>100
Regular?
Yes
P waves?
None
PR Interval?
QRS?
Wide >.12 sec
Same shape

29. Ventricular Tachycardia

30. Torsades de Pointes Rate? >100/min Rhythm? No P waves? None
PR Interval?
QRS width?
Wide > .12 sec
Polymorphic
Electrical rotation

31. Torsdaes de Pointes

32. Ventricular Fibrillation
Rate?
Atrial: None
Ventricular: Irregular and chaotic
Regular? No
P waves?
None
PR Interval?
QRS width?
Wide >.12 sec

33. Ventricular Fibrillation
Coarse Fib
Fine Fib

34. Idioventricular Rate? < 40/min Regular? Yes P waves? None
PR Interval?
QRS width?
Wide > .12 sec

35. Idioventricular

36. Accelerated Idioventricular
40 – 100/min
Regular?
Yes
P waves?
None
PR Interval?
Q waves?
Wide > .12 sec

37. Accelerated Idioventricular

38. Agonal Rate? Atrial: None Ventricular <20/min Regular?
Can be regular or irregular
P waves?
None
PR Interval?
QRS width?
Wide > .12 sec

39. Agonal

40. AV Heart Blocks

41. 1° AV block Rate? Atrial: 60 – 100/min
Ventricular: Same as atrial rate
Regular?
Yes
P waves?
Round, upright, uniform
PR Interval?
PR Interval >.20 sec
QRS width?
Narrow (M.B.W.W.A.C.)

42. 1° AV block

43. 2° AV block Type 1 (Wenckebach)
Rate?
Atrial: 40 – 60/min
Ventricular: < Atrial rate
Regular?
No (P’s are, QRS’s are not)
P waves?
Upright, round, consistent
P in front of every QRS
QRS does not always follow every P
PR Interval?
PR Interval gets progressively longer
QRS width?
Narrow (M.B.W.W.A.C.)

44. 2°Av block Type I (Wenckebach)

45. 2°AV Block Type II Rate? Atrial: 60 – 100/min
Ventricular: < Atrial Rate
Regular?
Can be either (P’s are regular, QRS’s are not)
P waves?
Round, upright, consistent
P in front of every QRS
QRS does not follow every P
PR Interval?
PR Interval is always the same
QRS width?
Narrow (M.B.W.W.A.C.)

46. 2° AV Block Type II

47. 3°AV Block (CHB) Rate? Atrial: 60 – 100/min Ventricular: 20 – 60/min
Regular?
Yes, but no
P to P is regular, R to R is regular (but not together)
P waves?
Round, upright, consistent
P – QRS relationship nonexistent
PR Interval?
PR Interval is always varied
QRS width?
Usually wide

48. 3°AV Block (CHB)

49. Pacemakers

50. Atrial Pacemaker
Rate?
Atrial: 60 – 100/min (ventricular follows atrial)
Regular?
Yes
May be irregular if demand pacemaker
P waves?
Round, upright, consistent
Small short pacemaker spike in front of P
PR Interval?
< .20 seconds
QRS width?
Narrow (M.B.W.W.A.C.)

51. Atrial Pacemaker

52. Ventricular Pacemaker
Rate?
Ventricular: 60 – 100/min
Regular?
Yes
May be irregular if demand pacemaker
P waves?
None
PR Interval?
QRS width?
Wide
Pacemaker spike in front of QRS

53. Ventricular Pacemaker

54. AV Sequential Pacemaker
Rate?
Atrial: 60 – 100/min
Ventricular: Same
Regular?
Yes
P waves?
Round, upright, consistent (preceded by spike)
PR Interval?
PR Interval < .20 sec
QRS width?
Wide (preceded by a spike)

55. AV Sequential Pacemaker

56. Let’s Practice!

57. Ventricular Fibrillation

58. 2°AV block (Wenckebach)

59. Torsades de Pointes

60. AV Sequential Pacemaker

61. 3° AV block (CHB)

62. Ventricular Pacemaker

63. Ventricular Tachycardia

64. 2° AV block Type II

65. Atrial Pacemaker

66. 1° AV block

67. 3° AV block (CHB)

68. In case you forget….

69. In case you forget…Part 2

70. In case you forget…Part 3

71. Scott S. Shadoin

72. Applause!!!

73. Psst! You want a few more???

74. Premature Atrial Conctraction (P.A.C.)
An early firing of atria, causes ventricles to contract
Identified by:
An early complex (irregular rhythm)
P wave looks different than rhythm
If it is really early P wave may be hidden in previous T wave

75. Premature Atrial Contraction (P.A.C.)

76. Premature Junctional Contraction (P.J.C.)
An early firing of the AV Junction, causes ventricles to contract
Identified by:
An early complex (irregular rhythm)
P wave irregularity
Missing, inverted, retrograde

77. Premature Junctional Contraction (P.J.C.)

78. Premature Ventricular Contraction (P.V.C.)
An early firing of a cell within the ventricle, causing it to contract
Identified by:
An early complex (irregular rhythm)
Wide, bizarre QRS that does not resemble others in the rhythm
1 – Complex
2 – Couplet
3 – Is a “RUN” or “SALVO” (considered V tach)

79. Premature Ventricular Contraction (P.V.C.)

80. P.V.C.’s – Part Deux! Bigeminy – Every OTHER beat is PVC
Trigeminy – Every THIRD beat is PVC
Quadrageminy – Every FOURTH beat is PVC

81. P.V.C.’s – Part Deux!

82. Ok, that’s really it….