1. CARDIAC
Rhythms
Arrhythmias
Dysrhythmias
Oh, my!
NUR240
Lecture 3
JB 9/10

2. Arrhythmia
ARRHYTHMIA – VARIATION IN
NORMAL RHYTHM
DYSRHYTHMIA – ABNORMAL,
DISTURBED RHYTHM
RESULTS FROM IMPULSE
FORMATION DISTURBANCE OR
CONDUCTION DISTURBANCE

3. AXIOM
ALL RHYTHM INTERPERTATION MUST
BE CORRELATED WITH SIGNS &
SYMPTOMS AND PATIENT
CONDITION…
“TREAT THE PATIENT,
NOT THE MONITOR”

4. Dysrhythmia
Impulse formation
(site of impulse origin)
SA Node Ectopic
AV Node Premature Beat
Ventricle

5. Dysrhythmia
Altered conduction
• Bradycardia / Tachycardia
• Flutter / Fibrillation
• Heart blocks

6. Basic Rhythm Strip Interpretation
1. Determine the rate. Does the atrial rate equal the
ventricular rate.
2. Is the rhythm regular/irregular?
3. Find the P wave. Is there a P wave for every
QRS?
4. Determine the PRI (Normal 0.12-0.20 sec)
5. Find the QRS (Normal <0.12seconds)
6. Any ectopic beats?
7. Find the T wave.
http:www.rnceus.com
EKG strip identification and evaluation

7. Determine heart rate
REGULAR RHYTHM – count boxes
between 2 “R” waves and divide
into 300
5
300 / 5 = 60
1 small box = .04 second 30 large boxes = 6 seconds
1 large box = .20 second 300 large boxes = 1 minute
15 large boxes = 3 seconds 1 mm = 0.1 millivolt (mV)

8. Determine heart rate
• Irregular rhythm – count R - R intervals
on a 6 sec. strip and multiply by 10

9. Normal Sinus Rhythm
• NORMAL SINUS RHYTHM IS
PRODUCED BY THE SA NODE
– P – WAVE FOLLOWS QRS COMPLEX IN A
PREDICTABLE RELATIONSHIP
– ALL “P” WAVES LOOK ALIKE, ALL QRS
COMPLEXES ARE NARROW
– R – R INTERVAL IS REGULAR
– RATE: 60 – 100 bpm

10. Normal Sinus Rhythm

11. Normal Sinus Rhythm

12. Sinus / Atrial dysrhythmia
• ORIGINATE FROM SA NODE OR ATRIA
(ABOVE VENTRICLES)
• CONDUCTION WITH VENTRICLE IS
UNDISTURBED
• USUALLY BENIGN & SYMPTOMATIC
• RHYTHM MAY BE IRREGULAR

13. Sinus / Atrial dysrhythmias
– SINUS TACHYCARDIA
– SINUS BRADYCARDIA
– ATRIAL FIBRILLATION
– ATRIAL FLUTTER
– Premature atrial contractions
– Paroxysmal atrial tachycardia
– Supraventricular Tachycardia

14. Sinus Tachycardia
• VENTRICULAR RATE  100 bpm
ETIOLOGY:
– MAY REFLECT PHYSIOLOGIC
DEMAND FOR  O2
– SYMPATHOMIMETIC DRUGS
– FEVER
– PAIN

15. Sinus Tachycardia
• CLINICAL SIGNS:
–  HR   MYOCARDIAL DEMAND
FOR O2

16. Treatment
– MAY RESOLVE WITH TREATMENT
OF UNDERLYING CAUSE
– DRUGS WITH RATE SLOWING
EFFECT: DIGOXIN, β-BLOCKERS
– CAROTID MASSAGE
– VAGAL MANEUVER

17. Sinus Bradycardia
• VENTRICULAR RATE =  60
ETIOLOGY:
RESPONSE TO MYOCARDIAL ISCHEMIA
VAGAL STIMULATION
ELECTROLYTE IMBALANCE
DRUGS
 I.C.P.
HIGHLY TRAINED ATHLETE

18. CLINICAL SIGNS
  C.O. IF BODY CAN’T COMPENSATE
OR IMPROVED C.O. DUE TO  DIASTOLIC
FILLING TIME MAY LEAD TO ARRHYTHMIA
• TREATMENT – DEPENDS ON CAUSE:
– ATROPINE
– AVOID VALSALVA
– HOLD RATE SLOWING DRUGS
I.E.: DIGOXIN, blockers

19. Atrial Flutter
• ATRIAL RATE = 250 – 400 IMPULSES/ MINUTE
– ETIOLOGY:
• OCCURS /W HEART DISEASE
• CAD
• VALVE DISORDERS
– CLINICAL SIGNS
• “SAW TOOTH” P-WAVES, CALLED F-WAVES
• ATRIAL RATE = 250 – 400/ MIN
• AV NODE BLOCKS SOME IMPULSES
• INCOMPLETE EMPTYING OF ATRIA CAUSE RISK
FOR THROMBUS GIVE
ANTICOAGULANTS

20. Atrial Flutter
• TREATMENT
– TREAT UNDERLYING CAUSE
  IRRITABILITY,  RAPID VENTRICULAR
RESPONSE
– DIGOXIN SLOWS RATE BY ENHANCING
AV BLOCK
– QUINIDINE SUPRESSES ATRIAL ECTOPIC
BEATS
– AMIODARONE
– CALCIUM CHANNEL & β-BLOCKERS
– CONSIDER CARDIOVERSION

21. Atrial Fibrillation
• CHAOTIC ELECTRICAL ACTIVITY IN
ATRIA
• ATRIA QUIVER (>500 beats/minute)
INSTEAD OF CONTRACTING AS A
UNIT
• ETIOLOGY: ADVANCED AGE
VALVE DISORDERS
CARDIOMYOPATHY

22. Atrial Fibrillation
“F” FIBRILLATORY WAVES
ø P-WAVES,
ø P-R INTERVAL
QRS normal
VENTRICULAR RATE IS IRREGULAR
RAPID VENTRICULAR RESPONSE 
PULSE DEFICIT

23. Atrial Fibrillation
TREATMENT
1. Amiodarone-may cause liver, lung damage and
worsening of arrhythmias. Pt to report SOB,
wheezing, jaundice, palpitations, lightheadedness
2. Pronestyl, Ca channel blockers, beta blockers,
digoxin
3. Synchronized cardioversion if unstable
4. Radio frequency catheter ablation
5. Anticoagulation therapy

24. Atrial Rhythms

25. Synchronized Electrical
Cardioversion
Oh O2 Saturation Monitoring
Say Suction Equipment
It IV Line
Isn’t Intubation equipment
So Sedation and possibly analgesics

26. Cardioversion
Synchronized shock with the QRS complex

27. JUNCTIONAL DYSRHYTHMIAS
• IMPULSE BEGINS IN AV NODE
• VENTRICULAR RATE IS EXTREMELY
SLOW
• MONITOR FOR SYMPTOMS OF
REDUCED CARDIAC OUTPUT AND
HEMODYNAMIC INSTABILITY

28. Paroxysmal Supraventricular
Tachycardia
• ABRUPT ONSET OF  HR
• ETIOLOGY: SNS STIMULATION
CARDIOMYOPATHY
• CLINICAL SIGNS:
ABRUPT ONSET/ CESSATION
S/S ARE RELATED TO  C.O.
RATE = 150 – 250 bpm

29. PSVT
• TREAT UNDERLYING CAUSE
– DRUGS: ADENOSINE, β-BLOCKERS,
DIGOXIN, MS, QUINIDINE
– CAROTID / VAGAL MANEUVERS
– SYNCHRONIZED CARDIOVERSION IF
UNSTABLE

30. Ventricular Arrhythmias
• ORIGINATES IN VENTRICLES
• PATIENT MAY BE SYMPTOMATIC,
REQUIRES IMMEDIATE ATTENTION
– PVC, couplet, bigeminy, trigeminy
– V-TACH (ventricular tachycardia)
– V-Fib (Ventricular fibrillation)

31. PREMATURE VENTRICULAR CONTRACTION
(PVC)
– EARLY IRREGULAR VENTRICULAR
BEATS
– QRS IS WIDE /BIZZARE
– CAN BE CHRONIC ASYMPTOMATIC
ABNORMALITY OR WARNING OF
SERIOUS DYSRHYTHMIA

32. PREMATURE VENTRICULAR CONTRACTION
(PVC)
• ETIOLOGY:
HYPOXIA
DIGOXIN TOXICITY
MECHANICAL STIMULATION
ELECTROLYTE (K) IMBALANCE
MI

33. PVCs

34. PREMATURE VENTRICULAR CONTRACTION
(PVC)
• CLINICAL SIGNS:
– DEPEND ON FREQUENCY
– PVC  SHORT DIASTOLIC FILLING TIME
 C.O.
– FREQUENT PVC – SENSATION OF
PALPATIONS, SKIPPED BEATS
– BIGEMINY – PVC EVERY OTHER BEAT
– TRIGEMINY – PVC EVERY 3RD BEAT

35. PREMATURE VENTRICULAR CONTRACTION
(PVC)
• TREATMENT:
– TREAT IMPAIRED HEMODYNAMICS
– ANTIARRHYTHMICS
– OXYGEN
– MONITOR FOR PVC LANDING ON
T-WAVE
– OBSERVE FOR UNIFOCAL (VS) MULTIFOCAL

36. Ventricular Arrhythmias
• VENTRICULAR TACHYCARDIA
– 3 OR MORE PVC’s
– QRS IS WIDE/ BIZARRE
EXTREMELY SERIOUS
MAY LEAD TO LETHAL RHYTHMS
• ETIOLOGY: SAME CAUSES AS PVC, ALSO
CARDIOMYOPATHY, MYOCARDIAL
IRRITABILITY

37. Ventricular Tachycardia

38. Treatment
– VT /W PULSE - CARDIOVERT
– MONITOR MORE CLOSELY
– PREPARE FOR CARDIOVERSION
(O2, LIDOCAINE, TREAT CAUSE)
– VT W/O PULSE - DEFIBRILLATE

39. VENTRICULAR FIBRILLATION
TOTAL UNORGANIZED MULTIFOCAL
RHYTHM, VENTRICLES QUIVER,
NO CARDIAC OUTPUT

40. V-fib
• ETIOLOGY:
SAME AS VT, PVC
SURGICAL MANIPULATION OF HEART
FAILED CARDIOVERSION
• CLINICAL SIGNS:
SAME AS CARDIAC ARREST
EKG SHOWS DISORGANIZED
RHYTHM

41. V-fib
• TREATMENT
IMMEDIATE DEFIBRILLATION X3
CPR
SURVIVAL IS < 10% FOR EVERY
MINUTE THE PATIENT REMAINS IN
V-fib

42. SCREAM for Vfib and
Pulseless VTach
1.Shock360J* monophasic, 1st and subsequent
shocks.(Shock every 2 minutes if indicated)
2.CPR After shock, immediately begin chest
compressions followed by respirations (30:2
ratio) for 2 minutes.
3.Rhythm check after 2 minutes of CPR (and
after every 2 minutes of CPR thereafter) and
shock again if indicated. Check pulse only if
an organized or non-shockable rhythm is
present.

43. SCREAM

44. CARDIAC ARREST
• VENTRICULAR ASYSTOLE
 80 – 90% DUE TO V-fib
 TOTAL ABSENCE OF ELECTRICAL AND
MECHANICAL ACTIVITY
• ETIOLOGY
TRAUMA
OVERDOSE
MI
• CLINICAL SIGNS
– ASYSTOLE or V-fib
– NO DEFINABLE WAVE FORMS
– ABSENCE OF VITAL SIGNS

45. Ventricular Asystole
Acronym Comments
T Transcutaneous Only effective with early
Pacemaker implementaion
E Epinephrine 1 mg IV q3-5 min
A Atropine 1 mg IV q3-5 min

46. PEA- Pulseless Electrical
Activity
• Asystole Algorithm
• PEA
• Problem search
• Epinephrine – 1mg IV/IO q3-5min
• Atropine- with a slow HR, I mg IV/IO q3-5min
• Consider termination of efforts if asystole
persists despite appropriate interventions.

47. CARDIAC ARREST
Review ACLS Guidelines 2005
TREATMENT: IMMEDIATE CPR
A. AIRWAY/ ADVANCED AIRWAY
CONTROL
B. BREATHING/ POSITIVE PRESSURE
VENTILATION
C. CIRCULATION/ CPR, START IV
D. DEFIBRILLATE (V-fib, V-tach ONLY)
E. DRUGS-Antidysrhythmic tx

48. CARDIAC ARREST
• EPINEPHRINE 1:10,000 IV PUSH
REPEAT Q 5 MIN.
• AMIODORONE:
• ATROPINE:
• VASOPRESSIN:
• CONSIDER ANTIARRHYTHMICS
• USE ACLS ALGORITHMS

49. CARDIAC ARREST
• TREATMENT: POST CARDIAC ARREST
MONITOR -
CARDIAC STATUS
RESPIRATORY STATUS
TREAT UNDERLYING CAUSE
EMOTIONAL SUPPORT
SAFE ENVIRONMENT

50. DEFBRILLATION (vs)
CARDIOVERSION
• DEFIBRILLATION
ASYNCHRONOUS ELECTRICAL DISCHARGE
THAT CAUSES DEPOLARIZATION OF ALL
MYOCARDIAL CELLS AT ONCE.
THIS ALLOWS (HOPEFULLY) THE SA NODE TO
RESTORE ITS PACEMAKER FUNCTION AND
DICTATE A REGULAR SINUS RHYTHM.
USED FOR PULSELESS V-tach AND V-fib
VOLTAGE: 200 – 360 joules (“stacked shock”)
or AED

51. CARDIOVERSION (aka)
SYNCHRONIZED CONVERSION
ELECTRICAL IMPULSE IS DISCHARGED
DURING QRS (VENTRICULAR
DEPOLARIZATION)
USUALLY TIMED /W CARDIAC MONITOR TO
PREVENT SHOCK ON
T-WAVE
USED FOR RAPID A-fib, V-tach /W PULSE AND
PERSISTENT PAT / PSVT
VOLTAGE: 50 – 100 joules

52. EQUIPMENT REVIEW
• DEFIBRILLATOR
SELECT ENERGY LEVEL, THEN CHARGE
• PADDLES
USE 25 POUNDS OF PRESSURE WHEN APPLIED TO
CHEST, Placed 2nd RICS and 5th LAAS
• CONDUCTING AGENT
GEL OR PAD WHICH ESTABLISHES SKIN CONTACT,
REDUCES SKIN BURNS
• JOULES
MEASUREMENT OF ELECTRICAL ENERGY
• DISCHARGES
NO ONE SHOULD COME IN CONTACT WITH PATIENT
OR BED DURING DISCHARGE

53. HEART BLOCK
• DEPRESSED CONDUCTION OF IMPULSE FROM
ATRIA TO VENTRICLES
• AV NODE BECOMES DEFECTIVE AND
IMPULSES (P-WAVES) ARE BLOCKED FROM
BEING TRANSMITTED TO VENTRICLES
FIRST DEGREE
SECOND DEGREE
TYPE I
TYPE II
THIRD DEGREE

54. 1° HEART BLOCK
• PR INTERVAL > 0.20 SECONDS
• CAUSES: MAY BE NORMAL VARIANT
INFERIOR WALL MI
DRUGS: DIGOXIN
VERAPAMIL
• TREATMENT:
MONITOR
OBSERVE FOR SYMPTOMS

55. FIRST DEGREE HEART BLOCK

56. 2° HEART BLOCK
• ONE OR MORE P-WAVES ARE NOT
CONDUCTED THROUGH THE
VENTRICLE
• HEART RATE - VENTRICULAR RATE
SLOW TO NORMAL
ATRIAL RATE MAY BE 2 – 4 X’s
FASTER THAN VENTRICULAR

57. 2° HEART BLOCK
CAUSES: ORGANIC HEART DISEASE
MI, Dig toxicity, B and Ca Channel
Blockers
DIGOXIN TOXICITY
SYMPTOMS
• Tx:
Monitor HR
Atropine
Temporary pacemaker
Avoid meds that decrease conductivity
2 TYPES OF 2° HEART BLOCK
MOBITZ TYPE I- Wenkeback
MOBITZ TYPE II

58. Second Degree Heart Block
Mobitz I
• PRI becomes progressively longer until
drops QRS

59. Second Degree Heart Block
Mobitz Type II
• PRI constant and regular, but in a 2:1 , 3:1
pattern

60. 3° HEART BLOCK
(COMPLETE HEART BLOCK)
• ATRIAL IMPULSES & VENTRICULAR RESPONSE
ARE IN TOTAL DISASSOCIATION
• P-WAVES ARE SEEN & ARE IRREGULAR
• QRS COMPLEX ARE SEEN & ARE IRREGULAR
(ESCAPE RHYTHM)
• NO CORRELATION BETWEEN P-WAVES & QRS
(RATE IS SLOW) – independent rhythms

61. 3° HEART BLOCK
(COMPLETE HEART BLOCK)
• CAUSES
ORGANIC HEART DISEASE
MI
DRUGS
ELECTROLYTE IMBALANCE
EXCESS VAGAL TONE
• SIGNS & SYMPTOMS
EXTREME DIZZINESS
HYPOTENSION
SYNCOPE
S/S OF  C.O.
ALTERED MENTAL STATUS

62. NSR vs 3 RD
Degree Block

63. 3° HEART BLOCK
(COMPLETE HEART BLOCK)
• TREATMENT
PACEMAKER
TEMPORARY
OR
PERMANENT

64. PACEMAKER
• Indications: Speed up a slow HR or Slow down a
rapid HR
• ELECTRICAL DEVICE THAT DELIVERS
CONTROLLED ELECTRICAL STIMULUS
THROUGH ELECTRODES PLACED IN CONTACT
WITH HEART MUSCLE
• 2 PIECES
PULSE GENERATOR IMPLANTED IN CHEST
WALL UNDER R CLAVICLE
PACEMAKER ELECTRODES IMPLANTED IN
MYOCARDIAL TISSUE

65. Paced Rhythm
• Pacemaker spike

66. PACEMAKER
• TEMPORARY
PACEMAKER
– USED IN
EMERGENCY
SITUATION
– FIXED
(COMPETITIVE)
PACEMAKER SENDS
STIMULUS TO
VENTRICLE AT A
FIXED RATE,
REGARDLESS OF
VENTRICULAR
ACTIVITY

67. Types of Pacemakers
Use a 5 letter code
system, first 3 used
more often:
1. Chamber being
paced: A, V, D
2. Chamber being
sensed: A, V, D, O
3. Type of response
by the PM to the
sensing: I, T, D, O

68. PATIENT TEACHING
• Carry PM ID card
• MEDI ALERT BRACELET
• Avoid swimming, golf and weight lifting
• AVOID MRI
• Check PM q3-6 mos.
• PACEMAKER SURVEILANCE
• Monitor pulse rates
• Don’t hold cell phones over generators

69. AUTOMATIC IMPLANTABLE
CARDIOVERSION DEFIBRILLATOR
(AICD)
• PROVIDES INTERNAL SHOCKS WHEN SERIOUS
ARRHYTHMIA IS DETECTED (V-tach OR V-fib)
• Has a pulse generator and a sensor that monitors
the heart
• If pt has dysrhythmia it delivers a shock which the
pt will feel
• USEFUL WHEN ARRHYTHMIA IS UNRESPONSIVE
TO MEDS OR SURGICAL ABLATION OR
IRRITABLE MYOCARDIAL TISSUE

70. References
• http://www.rnceus.com/ekg/ekgsecond2.html
• ACLS Guidelines 2005
• www.EMS-ED.net
• http://www.doctorshangout.com/forum/topi
cs/acls-algorithms-1