electrocardiography

1. ELECTROCARDIOGRAPHY

2. OBJECTIVES Review the anatomy and physiology of the electrical conduction of the heart Interpret the term elecrocardiography Describe the types of ecg monitoring Interprets the basics of ecg Determine the heart rate from ecg Explain the cardiac rhythm determinatation Understand the 12 lead ecg Differentiate the electrode placement Distinguish abnormal ecg from normal ecg

3. CONDUCTING SYSTEM OF HEART

4. ELECTROCARDIOGRAM ECG is a graphic representation of the electrical currents of the heart

5. TYPES OF ECG MONITORING Continuous electrocardiographic monitoring Hardwire cardiac monitoring Telemetry Ambulatory elecrocardiography Transtelephonic monitoring Wireless mobile cardiac monitoring systems

6. BASIC ELECTROCARDIOGRAPHY

7. P WAVE First wave seen Small rounded, upright (positive) wave indicating atrial depolarization ( and contraction) < 0.12 sec

8. QRS COMPLEX Three deflections following P wave Indicates ventricular depolarization ( andcontraction ) Q Wave: First negative deflection R Wave: First positive deflection S Wave: First negative deflection after R wave < 0.10 sec

9. PR INTERVAL Distance between beginning of P wave and beginning of QRS complex Measures time during which a depolarization wave travels from the atria to the ventricles 0.12 – 0.20 sec

10. ST SEGMENT Distance between S wave and beginning of T wave Measures time between ventricular depolarization and beginning of repolarization

11. T WAVE Rounded upright (positive) wave following QRS Represents ventricular repolarization

12. U WAVE Small rounded, upright wave following T wave Most easily seen with a slow HR. Represents repolarization of Purkinje fibers

13. QT INTERVAL Measured from beginning of QRS to end of T wave. Represents total ventricular activity

14. RATE DETERMINATION LARGE BOX METHOD Regular rhythms can be quickly determined by counting the number of large graph boxes between two R waves. That number is divided INTO 300 to calculate bpm ..

15. SMALL BOX METHOD Sometimes it is necessary to count the number of small boxes between two R waves for fast heart rates. That number isdivided into 1500 to calculate bpm .

16. 6 SEC STRIP The best method for measuring irregular rates with varying R-R intervals is to count the number of R waves in a 6-sec strip and multiply by 10.This gives the average number of bpm .

17. CARDIAC RHYTHM DETERMINATION REGULARITY Measure R-R intervals and P-P intervals. Regular : Intervals consistent Regularly irregular: Repeating pattern Irregular : No pattern

18. RATE The bpm is commonly the ventricular rate. If atrial and ventricular rates differ, as in a 3 rd degree block, measure both rates. Normal: 60–100 bpm Slow (bradycardia): 60 bpm Fast (tachycardia): 100 bpm

19. P WAVES If present: Same in size, shape, position? Does each QRS have a P wave? Normal: Upright (positive) and uniform Inverted: Negative Notched: P' None: Rhythm is junctional or ventricular

20. P R INTERVAL Constant: Intervals are the same. Variable : Intervals differ. Normal: 0.12–0.20 sec and constant

21. QRS COMPLEX Normal : 0.06–0.10 sec Wide: 0.10 sec None: Absent

22. LEADS OF ECG

23. LEAD PLACEMENT

24. NORMAL SINUS RHYTHM

25. SINUS BRADYCARDIA

26. SINUS TACHYCARDIA

27. PREMATURE ATRIAL COMPLEX

28. ATRIAL FLUTTER

29. ATRIAL FIBRILLATION

30. PREMATURE VENTRICULAR COMPLEX

31. VENTRICULAR TACHYCARDIA MONOMORHIC

32. POLYMORHIC

33. VENTRICULAR FIBRILLATION

34. VENTRICULAR ASYSTOLE

35. FIRST DEGREE AV BLOCK

36. SECOND DEGREE A.V BLOCK TYPE 1

37. TYPE 2

38. THIRD DEGREE A.V BLOCK

39. BUNDLE BRANCH BLOCK

40. ISCHEMIA ,INJURY,INFARCTION

41. ENLARGEMENTS LEFT ATRIAL

42. LEFT VENTRICULAR

43. RIGHT VENTRICULAR

44. ELECTROLYTE IMBALANCES

45. JOURNAL TIME

46. ANSWERS

47. RATE:214 bpm RHYTHM: regular P WAVE: none PR INTERVAL: none QRS COMPLEX: >0.12 bizarre INTERPRETATION: VT- MONOMORHIC

48. RATE: 75 bpm RHYTHM: regular P WAVE: normal PR INTERVAL:0.16 QRS COMPLEX:0.08 INTERPRETATION: NORMAL SINUS RHYTHM

49. RATE:50 -75 bpm RHYTHM: irregular P WAVE: normal PR INTERVAL:0.12- 0.28 QRS COMPLEX:0.08 INTERPRETATION:2 nd DEGREE A.V BLOCK TYPE 1

50. RATE: 35 BPM RHYTHM: regular P WAVE: normal PR INTERVAL: 0.16 QRS COMPLEX:0.10 INTERPRETATION: SINUS BRADYCARDIA

51. REFERENCES Crawford M H, DiMarco J P, Paulus W J. Cardiology.3 rd ed.Philadelphia:Elsevier publication;2010. Fauci A S, Braunwald E, Kasper D L, Hauser S L, Longo D L, Jameson J L.Harrison’s Principles of Internal Medicine.17 th ed (vol I).USA:McGraw Hill;2008.

52. Michael H.C, Paulus W.J. Cardiology .3 rd edn.Philadelphia:Elsevier;2010 Black M.J,Hawks H.K.Medical Surgical Nursing.7 th edn.Missouri:Saunders;2005 Johnson J.Y.Brunner and Suddharth`s : Textbook of Medical Surgical Nursing.11 th edn.Philadelphia:Lippincott;2008