1. Basic Dysrhythmias Chemeketa Paramedic Program -Basic Anatomy of the Heart -Electrical Conduction of the Heart -A System of Defining 3-Lead EKG’s

2. What is an: nEnEKG? nEnECG? nEnEEG? nEnEGG? nInIsn’t School Great?

3. Heart A & P n Location n Pieces, Parts n Important Vessels n Electrolyte Role n Pulling apart waveforms

9. Review of Important Vessels

10. CONDUCTION SYSTEM

11. A System of Checks & Balances n Baroreceptors (Pressoreceptors) – Found: n Internal carotid arteries n Aortic Arch n Chemoreceptors – Found in same places – Monitors pH, O 2 & CO 2 n Respond by: – Stimulating sympathetic n Adrenergic response n Alpha, Beta & Dopaminergic n Norepi & Epi release – Inhibiting Parasympathetic n Acetylcholine – Cholinergic Response – Medulla n Regulatory organ

12. Electrical Conduction System n Sympathetic-Thoracic/Lumbar Nerve – Norepinephrine n HR, Contractility n Parasympathetic-Vagus Nerve – Acetylcholine n HR (Valsalva) n Chronotropic-HR n Inotropic-Contraction

13. Electrolytes & Conduction n “Excitable” cells of the Heart n Self-depolarizing cells (Automaticity) n Electrolytes of the Heart (Na + / K+/ Ca++)

14. Electrolytes & Conduction n Membrane Potential (MP) – Slight difference between charge inside & out n Threshold – MP becomes high enough to depolarize n Action Potential – Ability of cells at a given time – Difference (mV) between inside & out

15. The Cardiac Cycle

16. Membrane Potential

17. Sodium-Potassium n MP Rises – Na + Channels Open – Rapid Influx (Fast Channels) n Cell Attains + Charge – K + Channels Open – Outflow n The Pump – ATP Transports: – 3 Na + out & 2 K + in – Restores Resting cellular conditions n Calcium – Slow Channels – Selective Permeability n “The Wave” – One cell contraction n Spreads

18. Electrical Conduction System n Na + - Depolarization n K + - Repolarization – > = < Automaticity & Conduction – Irritability n Ca ++ - Depolarization and Contraction – > = > Contractility – Irritability

19. Electrical Conduction System n Na + in & K + out = Depolarization n K + in & Na + out = Repolarization – Imbalances in K + or Na + n Effects Automaticity & Conduction n Hypo & hyperkalemia affects irritability n Ca ++ - Depolarization and Contraction – Affects Contractility – Hypo & Hypercalcemia effects contractile force

20. I know what you’re thinking… Who gives a @#$% !!! n You are caring for a patient with a rapid heart rate. You follow protocols and administer 20mg of Diltiazem. – You’re patient responds by becoming: n Less responsive n Bradycardic n B/P drops to 72/40 n Weak Pulse at wrist n Not responding to fluid, time or positioning. n What now??? n Calcium Gluconate 10% – 500 – 1000 mg slow IV Push @#$% = Dang

21. Phases n Phase 0 – Rapid Depolarization – Reached max potential -90mV – Fast Na + Channels Open – Cell now positive +25mV n Phase 1 – Early Rapid Repolarization – Fast Na + Channels Close – K + still being lost – MP approaching 0mV n Phase 2 – Prolonged Slow Repolarization – Plateau Phase – Muscle finishing contraction – Beginning to relax – MP staying close to 0mV

22. Phases n Phase 3 – End of Rapid Repolarization – K + returns to inside – Cell returns to -90mV – Almost ready n Phase 4 – Na + - K + Pump turns on n Sends Na + out n Brings K + in n Ready to do it all over again now

23. Refractory Periods Excuse me!!! I hate to interrupt again, but, who cares??? n Absolute Refractory Period – Polarity of cell prohibits depolarization n Relative Refractory Period – Cell is returning to ready state for depolarization – Impulse now is BAD!!! n R on T Phenomenon – Causes VT & VF – Treated with defibrillation n Can be caused by: – Frequent FLB’s – EMT-P not pushing the “sync” button

24. The Electrocardiograph (ECG, EKG) n Electrical Activity – Not Heart Action n Records + and – impulses n Paper runs at 25mm/s n Counting Rates – 300-150-100-75-60-50 – 6 second strip x 10 – 10 Second Strip x 6 – The little number on the monitor

25. Lead Considerations n $25,000 mVoltmeter – Lead Views: n 1 – Lateral n 2 – Inferior n 3 – Inferior

26. The Components n SA Node n Internodal Pathways n AV Junction n AV Node n Bundle of His n L & R Bundle Branch n Purkinje Network n Purkinje Fibers

27. Ode to a Node n Have a heart, and have no fear, The SA node is over here. Beating at a constant rate, 60 – 100 is really great. The AV node can make a show, If SA node has gone too slow. 40 – 60 is not too bad If it’s all you’ve got, you will be glad. Should the whole thing drop it’s speed, His and bundle branches will take the lead. And that, my friend is the whole and part, Of the conduction system of your heart. – Flip and See ECG, Cohn/Gilroy-Doohan

28. Sino Atrial Node n The Natural “Pacemaker” – Connects directly to atrial fibers n Fires 60-100 times per minute n Wavelike Atrial Depolarization n The P-Wave P-Wave P-R Interval Q- Wave.04 Sec 0.20 Seconds per 5 Boxes

29. AV Junction n Receives impulses from SA Node via the Atrial Cells – An electrical funnel – Impulses hit at various times – Causes delay n PR-I – Susceptible to blockage n Path from A to V – Delivers impulse to the AV Node

30. Atrio-Ventricular Node n Lies between the Atria and Ventricles n Collects impulses from above n Stimulates Ventricles n If unstimulated – Intrinsic rate 40-60

31. Bundle of His / Left and Right Bundle Branches n Distributes Impulses from the Node n “The Ventricular Messengers”

32. Purkinje Network/Fibers n Direct connection with ventricular tissue n Intrinsic rate 20-40 if unstimulated P-Wave P-R Interval QRS Complex T-Wave

33. P-Wave P-R Interval QRS Complex T-Wave Q R S PRI Baseline

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

35. Step 1 = Rate n Is the rate between 60-100 (Sinus) n Between 40-60 (Junctional/Bradycardic) n Above 100 (Tachycardic) n Between 20-40 (Ventricular)

36. Step 2 = Regularity n At-a-glance: Does it look regular? n Are the P-Waves evenly spaced? n Are the QRS Complexes evenly spaced?

37. Step 3 = P-Waves n Are P-Waves present? n Are they upright and rounded? n Are they irregular in any way: Notched / Peaked / Depressed…? n Are they all the same?

38. Step 4 = P-R Interval n Is the P-R Interval between 0.12-0.20? n Is it too long / too short? (Block) n Is it the same on every conduction? n Is it absent?

39. Step 5 = QRS Complex n Is it there? n Is it between 0.04 - 0.12? n Does it have any abnormalities? (Notched / Rabbit Eared / Wide / Bizarre)

40. Step 6 = P-QRS Married? n Is there a P-wave for every QRS? n Are there more P-Waves than QRS? n Are the P-Waves after or within the QRS?

41. Describe What You’ve Found!!! n IN GENERAL (underlying rhythms)!!! n What are the abnormalities? n Does it originate in the Sinus Node? n Does it follow through from the Atria to the ventricles? Are there abnormal delays? n What are the exceptions to the underlying rhythm? (Describe those also)

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

44. Sinus Arrhythmia n Rate: 60 - 100 n Regularity: Irregular n P-Waves: Present and Normal n P-R I: 0.12-0.20 sec n QRS: 0.04-0.12 sec and Normal n Married: 1 P: 1 QRS, no extras or shortages

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

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

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

48. Atrial Flutter n Rate: Usually tachy n Regularity: Atria Regular Ventricles May be Irregular n P-Waves: Sawtooth Pattern 2:1, 3:1, 4:1... n P-R I: 0.12-0.20 sec on conducting beat n QRS: 0.04-0.12 sec n Married: P-waves outnumber QRS n (Picket fence)

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

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

51. 1st Degree Heart Block n Rate: 60 - 100 n Regularity: Very n P-Waves: Present and Normal n P-R I: Longer than 0.20 sec n QRS: 0.04-0.12 sec and Normal n Married: 1 P: 1 QRS, no extras or shortages

52. 2nd Degree Heart Block (Type 1) Wenkebach n Rate: Can be Normal, or usually brady n Regularity: Irregular n P-Waves: Present and Normal n P-R I: Lengthens until beat is dropped n QRS: 0.04-0.12 sec and Normal n Married: P-wave present on conducting beats, increased delay causes missed QRS

53. 2nd Degree Heart Block (Type 2) Mobitz II n Rate: Less than 60 n Regularity: Irregular n P-Waves: Present, 2:1, 3:1, 4:1 n P-R I: 0.12-0.20 sec on conducting beat n QRS: 0.04-0.12 sec, may begin to widen n Married: P-wave for every QRS and extras depending on conduction ratio

54. 3rd Degree Heart Block (CHB) Complete Heart Block n Rate: Ventricular Rate 40-60 n Regularity: Atria-Regular Vent-Regular n P-Waves: Present and Normal n P-R I: Atria independent of Ventricles n QRS: Usually greater than 0.12 sec n Married: P-waves completely unrelated to QRS Complexes.

55. Complete Heart Block

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

57. Junctional

58. Junctional Accelerated Rhythm n Rate: 60-100 n Regularity: Regular n P-Waves: Inverted, Retrograde or Absent n P-R I: Shortened or absent n QRS: 0.04-0.12 sec n Married: P-wave for every QRS, sometimes not visible

59. Accelerated Junctional

60. Junctional Tachycardia n Rate: 100-140 n Regularity: Regular n P-Waves: Inverted, Retrograde or Absent n P-R I: Shortened or absent n QRS: 0.04-0.12 sec n Married: P-wave for every QRS, sometimes not visible

61. Junctional Tachycardia

62. Ventricular Tachycardia n Rate: 100-220 n Regularity: Regular n P-Waves: None n P-R I: None n QRS: Greater than 0.12 sec n Married: NO We’ll look at Torsades de Pointes in Lab

63. Ventricular Tachycardia

64. Ventricular Fibrillation n Rate: No ventricular rate n Regularity: Irregular n P-Waves: No n P-R I: No n QRS: No, unorganized ventricular baseline n Married: No

65. Ventricular Fibrillation

66. Asystole n Rate: 0 n Regularity: N/A n P-Waves: None n P-R I: N/A n QRS: None n Married: No (verify a second lead)

67. Asystole

68. Agonal / Idioventricular n Rate: 20-40 n Regularity: Irregular n P-Waves: None n P-R I: N/A n QRS: Wider than 0.12 sec n Married: NO (a dying heart)

69. Idioventricular n Less regular than this!

70. Exceptions / Disruptions n Premature Ventricular Contractions n Premature Atrial Contractions n Bundle Branch Blocks n Pacer Considerations (Atrial, Ventricular or Both)

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

72. PVC’s

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

74. PJC

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

76. Paced Rhythms n Patients may have various types of pacemakers n Atrial n Ventricular n Both n Vertical spike on monitor is an indicator

77. Paced Rhythms Various

78. Artifact n 60 Cycle Interference n Loose Leads/Moving Ambulance

79. In Summary n Really Cool Physiology!!! n GENERAL RULES to Interpretation – Applicable to 3 – lead monitoring n Practice, Practice, Practice… n Remember the rules, NOT how it looks coming from one patient or one rhythm generator!!!

80. Sources – In order of preference n Many of the pictures and info from: – Flip and See ECG, 2 nd Edition n Cohn/Gilroy-Doohan – A great resource – Paramedic Paramedic Textbook, Revised 2 nd Edition n Mick J. Sanders, Mosby – ECG’s Made Easy, 2 nd Edition n Barbara Aehlert, RN, Mosby – Basic Dysrhythmias, Interpretation and Management, 3 rd Edition n Robert J. Huszar, Mosby