1. EKG Interpretation

2. SELU NLAB 335 Fall 20142 1. Demonstrate proper lead placement for cardiac monitoring 2. Analyze each component of an EKG wave form 3. Utilize a 5-step method to interpret an EKG rhythm strip 4. Identify the following dysrhythmias: 1. Normal Sinus Rhythm 2. Sinus Bradycardia 3. Sinus Tachycardia 4. Supraventricular Tachycardia (SVT) 5. Atrial Fibrillation 6. Atrial Flutter 7. Premature Ventricular Contractions (PVCs) 8. Ventricular Tachycardia (VT) 9. Ventricular Fibrillation (VF) 10. Asystole 11. Pulseless Asystole (PEA) 5. Demonstrate defibrillator safety to include clearing area, charging, discharging, and how to use defibrillator pads 6. Differentiate between defibrillation and cardioversion 2

3. SELU NLAB 335 Fall 20143 Right Side of Heart  Receives blood returning from the body  Waste products mostly carbon dioxide  Pumps blood to lungs  Left Side of Heart  Receives blood returning from the blood vessels in the lungs  Richly oxygenated blood  Pumps the blood to the body 3

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5. 5 Right Coronary Artery  Originates from the aorta, distal to the aortic valve  RCA distributes blood to the RA, RV, and variable portions of the LA and LV 5

6. SELU NLAB 335 Fall 20146 Left Coronary Artery  Originates from the base or ascending aorta.  LCA distributes (+/- 85%) blood to both ventricles, the inter- ventricular septum and left atrium. 6

7. SELU NLAB 335 Fall 20147 Coronary Sinus  Most blood supplied by the coronary arteries is returned to the right atrium by way of the coronary sinus  Failure of the coronary circulation causes ischemic heart disease. 7

8. SELU NLAB 335 Fall 20148  SA Node (1.)  Normally dominant and primary pacemaker of heart  Located high in right atrium  Inherent Firing Rate: (60 to 100) 8

9. SELU NLAB 335 Fall 20149  AV Node (2.)  Receives impulse from SA node  Coordinates impulse and transmits them to ventricles  AV node receives impulse before atria have finished contracting  Rate: 40-60 bpm  Escape pacemaker 9

10. SELU NLAB 335 Fall 201410  Bundle of His (3.)  Bifurcates in the to the right and left bundle branches (4.)  The cells of each bundle branch extend through the interventricular septum  The muscular wall that separates the right and left ventricles  Rate: ≤ 40 BPM 10

11. SELU NLAB 335 Fall 201411  Purkinje Fibers (5.)  Originate from bundle branches  They are no longer branches but (terminal) individual fibers  Coordinates impulse & transmits them to ventricles  AV node receives impulse before atria have finished contracting 11

12. SELU NLAB 335 201412 Skin Preparation:  Clean with alcohol wipe if necessary. If the patients are very hairy – shave the areas.  ECG monitoring lead  Lead II: is between the right arm and left leg electrodes, the left leg being positive. 12 RA C RL LA LL

13. SELU NLAB 335 Fall 201413  RA – White Electrode  Below R Clavicle,2 nd ICS, Right Midclavicular line  RL – Green Electrode  R lower ribcage, 8 th ICS, Right Midclavicular line  LA- Black Electrode  Below L Clavicle,2 nd ICS, Left Midclavicular line  LL- Red Electrode  Below R ribcage,8 th ICS, Left Midclavicular line  Chest – Brown Electrode  4 th ICS, right sternal border 13 RA C RL LA LL

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17. SELU NLAB 335 Fall 201417  Indicates electrical impulse originating in SA node  Normal depolarization (Contraction ) of the right and left atria  The normal P wave is upright.  The P wave is absent in atrial fibrillation, atrial flutter, VF, VT and asystole. 17

18. SELU NLAB 335 Fall 201418  The PR interval is the distance (time) between the beginning of the P wave and the beginning of the QRS complex.  It actually ends at the beginning of whatever the first wave in the QRS complex is. 18

19. SELU NLAB 335 Fall 2014 19  A normal PRI should be in the range of 0.12 - 0.20 seconds.  Memorize this.  Since we already know that each square represents 0.04 sec, we are able to calculate that 0.12 seconds is three squares and that 0.20 seconds is five squares. 19 A longer interval indicates first degree heart block

20. SELU NLAB 335 Fall 201420  Produced by ventricular depolarization  The QRS begins at the point where the PRI stops. This is either the beginning of the Q wave; if there is no Q wave, it starts at the beginning of the R wave. 20

21. SELU NLAB 335 Fall 201421  Q wave  The first negative deflection in the QRS complex  R wave  The first positive deflection in the QRS complex.  S wave  The first negative deflection that extends below the baseline in the QRS complex. 21

22. SELU NLAB 335 Fall 201422  Normal QRS interval is 0.06 – 0.11 seconds  If it is 0.12 seconds or above, there is definite delay in conduction through the ventricle  Shape: generally narrow and pointed 22

23. SELU NLAB 335 Fall 201423  ST segment – From the end of the QRS complex (ventricular depolarization) to the beginning of the T wave (ventricular repolarization)  Segment is usually isoelectric or flat  Elevation or depression may represent injury or disease of ventricular muscle  If not smooth, look for a P wave in it 23

24. SELU NLAB 335 Fall 201424  T wave – Deflection produced by ventricular repolarization  Direction of the normal T wave is positive  T wave always follows the QRS complex Peak of the T is the most vulnerable (relative refractory period) 24

25. SELU NLAB 335 Fall 201425 1. Analyze the rate 2. Analyze the rhythm 3. Analyze the P wave and P-QRS relationship 4. Analyze the P-R intervals 5. Analyze the QRS intervals 25

26. SELU NLAB 335 Fall 201426  A normal sinus rhythm can be seen below. The identical 'P' waves preceding all the 'QRS' complexes are circled.  What is the heart rate? 26 21 3 4 6 5 6 x10 = 60 bpm

27. SELU NLAB 335 Fall 201427  What is the heart rate?  8 x 10= 80 bpm 27 142 3 6578

28. SELU NLAB 335 Fall 201428  Use paper or calipers  Measure the regularity of the rhythm  Look for consistency in P-P intervals (atrial rhythm) and R-R intervals (ventricular rhythm) 28

29. SELU NLAB 335 Fall 201429  Should be upright and smooth in Lead II  In a normal sinus rhythm every P wave is followed be a QRS complex. 29

30. SELU NLAB 335 Fall 201430  All P-R intervals should be the same no matter what lead is observed P-R interval should be within.12 -.20 seconds  Shorter or longer P-Rs usually are caused by a conduction defect 30

31. SELU NLAB 335 Fall 201431  1st Degree AV block is caused by a conduction delay through the AV node but all electrical signals reach the ventricles. This rarely causes any problems by itself and often trained athletes can be seen to have it.  The normal P-R interval is between 0.12s to 0.20s in length, or 3-5 small squares on the EKG. 31

32. SELU NLAB 335 Fall 201432  Each QRS should be similar in appearance & follow P wave  QRS should be no greater than 0.11 seconds  QRS 0.12 or longer denotes a delay in ventricular conduction, usually a bundle branch block 32

33. SELU NLAB 335 Fall 201433  Rhythm - Regular  Rate - (60-100 bpm)  QRS Duration - Normal  P Wave - Visible before each QRS complex  P-R Interval - Normal (< 0.20)  Indicates that electrical impulse is generated by SA node & traveling through normal conduction system. 33

34. SELU NLAB 335 Fall 201434  Rhythm - Regular  Rate - < 60  QRS Duration - Normal  P Wave - Visible before each QRS complex  P-R Interval - Normal  Can be caused by meds such as beta-blockers or digoxin 34

35. SELU NLAB 335 Fall 201435  Rhythm - Regular  Rate - >100 beats per minute  QRS Duration - Normal  P Wave - Visible before each QRS complex  P-R Interval - Normal  Impulse generating heart beats WNL, but they are occurring at a faster pace than normal. Seen during exercise, fever, dehydration. 35

36.  Rhythm - regular  Rate – 150 to 250  P waves – may be indistinguishable as P waves run into preceding T waves  P-R –usually not measurable SELU NLAB 335 Spring 2014 36

37.  QRS – usually narrow complex  Treatment:  Vagal maneuvers (terminates 25%)  Medications: adenosine SELU NLAB 335 Spring 2014 37

38. SELU NLAB 335 Fall 201438  Many sites within the atria are generating their own electrical impulses, leading to irregular conduction of impulses to ventricles. This irregular rhythm can be felt when palpating a pulse. 38

39. SELU NLAB 335 Fall 201439  Rhythm - Irregularly irregular  P wave – none (fibrillatory waves at rate of 300-600)  P-R interval – not measurable  Ventricular rate - usually 100-160 beats per minute but slower if on medication  QRS Duration - Usually normal 39

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41. SELU NLAB 335 Fall 201441  Rhythm – Usually regular  Rate – (atrial) – 250-350, ventricular - varies  QRS Duration - Usually 0.10 sec or <  P Wave - Replaced with multiple “f” (flutter) waves, usually at a ratio of 2:1 (2f - 1QRS) but may be 3:1 or 4:1 (“sawtooth” waves)  P-R Interval - Not measurable  CAD, HTN, mitral valve disorders, cardiomyopathy 41

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43. SELU NLAB 335 Fall 2014 43  Due to ventricles depolarizing earlier than they should  Rhythm - Irregular  Rate – Usually normal  QRS Duration - Normal except for irregular beats  P Wave - Ratio 1:1  P Wave - Normal & same as QRS rate  P-R Interval - Normal except no PR interval with PVCs

44. SELU NLAB 3835Fall 2014 44  These ventricles are depolarizing prematurely in response to a signal within ventricles.  The impulses are coming from more than one site in the ventricles (multifocal PVCs). 44

45. SELU NLAB 335 Fall 201445  Rhythm - Regular  Rate - >100, usually 110-250  P wave – not seen  QRS –wide-complex - >0.12  Results from abnormal tissue in ventricles generating a rapid and irregular heart rhythm. Poor cardiac output is associated with this rhythm thus causing the patient to go into cardiac arrest. Defibrillate if patient is unconscious & pulseless. 45

46. SELU NLAB 335 Fall 201446  Disorganized electrical signals cause the ventricles to quiver instead of contract in a rhythmic fashion. A patient will be unconscious as blood is not pumped to the brain. Immediate treatment by defibrillation is indicated. This condition may occur during or after AMI. 46

47. SELU NLAB 335 Fall 201447  Looking at the ECG you'll see that:  Rhythm - Irregular  Rate - 300+, disorganized  QRS Duration - Not recognizable  P Wave - Not seen  This patient needs to be defibrillated!! QUICKLY 47

48. SELU NLAB 335 Fall 201448  MONA  S-T Element –elevated (STEMI) as in above EKG strip  NSTEMI also possible  Goal is early reperfusion: fibrinolytics or PCI  Be prepared to provide CPR & defibrillation 48

49. SELU NLAB 335 Fall 201449  No discernible electrical activity – “flat line”  Confirm in another lead  CPR!! – epinephrine  Can be final rhythm of patient initially in VF or VT  Very poor prognosis 49

50. SELU NLAB 335 Fall 201450  For this electrical procedure, low- energy shocks are given to the heart to trigger a normal rhythm. Pt is sedated before shocks are given unless it is emergent situation. This type of cardioversion can be done in hospital as OP procedure.  Chemical cardioversion also can be done by taking medications that correct dysrhythmias. 50

51. SELU NLAB 335 Fall 201451  An ECG of a cardioversion is shown.  On the left, the heart rhythm is atrial fibrillation characterized by a fast, irregular rhythm.  An electrical countershock is delivered across the heart (black arrowhead) restores the heart rhythm to normal (right)

52. SELU NLAB 386 Fall 201252 1. Obtain consent if elective, nonemergent procedure. 2. Sedate patient (propofol commonly used) 3. Turn on defibrillator and select proper energy level (lower energy than defibrillation). 4. Apply pads to patient’s chest & press “Sync” button on defibrillator. 5. Charge paddles; place on chest wall with one paddle to right of sternum just below clavicle and the second to lower left chest. 6. Apply 20-25 lbs. of pressure to paddles; call “all clear”; depress buttons at same time to discharge electrical current.. 7. Check cardiac monitor for rhythm & return of pulse.

53. SELU NLAB 335 Fall 201453  Synchronized Cardioversion is used to prevent R on T  Occasionally 'QRS' complex of PVC will fall on top of a sinus 'T' wave. When this occurs, it is often called an 'R' on 'T' phenomenon. This situation is often considered more dangerous to the patient than other PVCs because it can often lead to ventricular tachycardia. 53

54. SELU NLAB 335 Fall 201454  Defibrillation is a process in which an electronic device gives an electric shock to the heart. This helps reestablish normal rhythm in a heart having dangerous dysrhythmia or in cardiac arrest.  Taylor’s Clinical Guide Skill 16-7 (p. 862-865) 54

55. SELU NLAB 335 Fall 201455  Don’t wait to defibrillate!!!!

56.  The traditional monophasic waveform directs energy in a single direction through the patient's chest.  The biphasic waveform reverses the direction of the electrical energy near the midpoint of the waveform SELU NLAB 335 Fall 201456

57.  Pulseless electrical activity (PEA) is a clinical condition characterized by unresponsiveness and lack of palpable pulse in the presence of organized cardiac electrical activity.  Patients with PEA have NO pulse in the presence of organized electrical activity SELU NLAB 335 Fall 201457

58.  1)Hypovolemia *  2)Hypoxia*  3)Hydrogen ion (acidosis)  4)Hyperkalemia/ Hypokalemia  5)Hypothermia  * (most common)  1)Toxins (eg, tricyclic antidepressants, calcium channel blocker, beta- blockers)  2)Thrombosis (coronary or pulmonary)  3)Trauma  4)Tamponade, cardiac  5)Tension Pheumothorax SELU NLAB 335 Fall 201458

59.  Initiate CPR.  IV/IO access  IV Bolus  Intubate  Correct hypoxia by administering 100% oxygen  Seek & correct reversible cause  Epinephrine 1mg dose IV/IO every 3-5 min during PEA arrest.  Continue CPR throughout  If underlying rhythm becomes shockable, DEFIBRILLATE  Patients with PEA have poor outcomes. (AHA) SELU NLAB 335 Fall 201459