1. Guide For Arrhythmia Recognition
Cheryl Sabin, MSN, ANP
And other ANP faculty, Indiana University

2. Objectives
Recognize and explain the basic conduction system of the heart
Able to accurately measure:
PR interval
QRS duration
QT interval
Analyze the rate and rhythm of EKG strips

3. Objectives
Recognize and distinguish what area of the conduction system is pacing the heart
Able to state appropriate treatment responses to various identified rhythm strips

4. The ECG
Electrodes on the skins surface records the electrical activity of the heart.
Monitoring cables are connected to the skin electrodes and attached to the monitor or ECG machine
The horizontal axis corresponds with time.
The vertical axis = voltage or amplitude.

5. ECG Paper ECG paper normally records at 25mm/se
Each horizontal 1mm box represents 0.04 sec. (25mm/sec x 0.04 sec = 1mm).
Show Basic Dysrhythima

6. ECG Paper
The lines between every 5 boxes are heavier indicating one large box. Each large horizontal box is 0.20 sec
5 large boxes = 1 sec.
Thirty large boxes = 6 sec.
A small box is 1 mm high, a large box is 5mm high.

7. Paper

8. Waveform
Movement away from the baseline in either a positive or negative direction
Segment
A line between waveforms; named by the waveform that precedes or follows it
Interval
A waveform and a segment
Complex
Several waveforms

9. *Waveform*
P Wave: represents atrial depolarization and the spread of the electrical impulse throughout the right and left atria.
P Wave Characteristics:
Smooth & round
No more than 2.5 mm in height or 0.11 sec in duration
First ½ of the P reflects stimulation of the right atrium.
The downward slope of the P represents stimulation of the left atrium

10. PR
PR Segment: horizontal line between the end of the P wave and the beginning of the QRS complex.
Normally isoelectric
PR Interval: P wave + PR segment = PRI
Represents the interval between the onset of atrial depolarization and ventricular depolarization.

11. PRI
Time from impulse from SA to AV node

12. PR Cont. PR Interval cont.
Measured from the point where the P wave leaves the baseline to the beginning of the QRS.
Normally measures 0.12 to 0.20 sec.
Normally shortens as heart rate increases.

13. QRS
QRS Complex: consists of the Q, R, & S waves and represents the spread of electrical impulse through the ventricles. Ventricular depolarization.
Q Wave: is always a negative waveform.
It represents depolarization of the interventricular septum
Measures less than 0.04 sec in duration and less than 25% of the amplitude of the R wave.

14. Waveforms R Wave: is the first positive deflection of the QRS
S Wave: is a negative deflection following a R wave.

15. Waveforms
The R & S wave represents the simultaneous depolarization of the R & L ventricles.
The QRS complex typically represents the electrical activity which occurs within the Left ventricle due to it’s greater muscle mass.

17. QRS
Measuring of QRS
The width of the QRS is taken from the point where the first wave of the complex leaves the baseline. The point at which the last wave form returns to the baseline marks the end of the QRS complex.
Duration of the QRS varies between 0.06 and 0.10 sec.

18. ST ST Segments: portion between the QRS complex and the T wave.
Is the term used regardless of the final wave of the QRS.
Represents the early part of repolarization of the R&L ventricles.
Normal ST segment is isoelectric

19. Waveforms T Wave: Represents ventricle repolarization.
The absolute refractory period ends at the peak of the T wave and the relatively refractory period begins.

20. Waveform T Wave Characteristics:
The T wave is typically oriented in the same direction as the preceding QRS complex.
The T wave is slightly asymmetric

21. QT
QT Interval: Represents the time from ventricular depolarization to repolarization.
QT is measured from the beginning of the QRS complex to the end of the T wave.
To determine if the QT is WNL: measure between R-R waves. If the QT interval is less than ½ the R-R interval it is considered normal.

22. QTc Interval Table HR/min R-R Interval (sec) QTc (sec) & Normal range40
1.5
0.46( ) 50
1.2
0.42( ) 60
1.0
0.39( ) 70
0.86
0.37( ) 80
0.75
0.35( ) 90
0.76
0.33( )

23. QTc Interval Table HR/min R-R Interval (sec) QTc (sec) & Normal range
100
0.60
0.31( )
120
0.50
0.29( )
150
0.40
0.25( )
180
0.33
0.23( )
200
0.30
0.22( )

24. Calculating Rate Assess the Rate:
Six-second Method: 30 large boxes = 6 sec.
Ventricular Rate: count the number of QRS complexes in the 6 sec. strip and multiply that number by 10.
Large Box Method:
Count the number of large boxes between 2 consecutive R waves and divide into May also calculate the Atrial rate the same way.

25. Calculating Rate Sequence Method:
Select an R wave that falls on a dark vertical line. Number the next 6 consecutive dark vertical lines as follows: 300, 150, 100, 75, 60, and 50.

26. Sinus Rhythms Normal Sinus Rhythm or Regular Sinus Rhythm(NSR,RSR)
Rate:
Rhythm: regular.
P waves Configuration: All look alike; upright in standard leads I,II, aVF, inverted in aVR
P-R interval: Normal seconds and constant
QRS duration: Normal seconds.

27. NSR

28. Sinus Bradycardia Rate: less than 60 beats per minute.
Rhythm: Regular.
P waves: Configuration: all look alike(see NSR) one P before each QRS.
P-R interval: Normal seconds and constant.
QRS duration: Normal seconds.

29. Sinus Brady What drugs induce SB? When do you treat SB?
Why do they have symptoms?
Cardiac output = ( HR X SV)

30. Sinus Tachycardia (Sinus Tach)
Rate: ( maybe 180, depends on who’s book you read!)
Rhythm: Regular
P waves: All look alike( see NSR). One P wave before each QRS
PRI: Normally shortens as heart rate increases.
QRS duration: Normal sec.

31. Sinus Tach

32. Sinus Arrhythmia (happens to all of us!)
Rate: but it is variable. Rate increases with inspiration and decreases with expiration.
Rhythm: Irregular; varies with respiratory cycle

33. Sinus Arrest Rate: Variable; often slow
Rhythm: Interrupted by pauses when the SA node “fails to fire.” Regular until absence of a P wave; duration of the pause is not a multiple of the P-P interval or the underlying rhythm

34. Sinus Arrest

35. Sinus Block(SA Exit Block)
Impulse originates in pacemaker cells of SA node but is blocked as it exits.
Rate: Variable; often slow
Rhythm: Regular except for pause periods; overall the rhythm is not interrupted.

36. SA block

37. Atrial Arrhythmias Premature Atrial Contractions
P waves: Shape of premature P wave often differs. One P wave for each QRS. PAC occurs early; no compensatory pause(usually).
P-R interval: Interval for PAC usually different than is sinus cycles.
QRS duration: Normal duration; QRS of premature beat usually the same as the sinus conducted QRS
Rhythm: Interrupted by premature contraction

38. NSR PAC

39. Atrial Tachycardia Paroxysmal Atrial Tach-PAT
Rate:
Rate is the only difference from Sinus Tach.
Rhythm: Regular unless associated with AV block-PAT marked by sudden onset and sudden cessation.
P waves: Often buried in preceding T wave-tent like appearance.One P for each QRS
P-R interval: Not measurable because of rapid rate.

40. Atrial Flutter
Rate: Ventricular rate varies depending upon the degree of AV block( ).It is Regular.
Rhythm: Dependent on block; regular if block is constant
P Waves: Flutter waves are saw tooth pattern or undulating atrial waves.
P-R interval: Not measured.
QRS duration: Normal

41. A. Flutter pathways
In atrial flutter, the electrical signal gets trapped in a loop running around the right atrium, causing it to beat at 300 beats per minute while the ventricles beat usually at 150 beats per minute. The abnormal tissue causing this rhythm problem is located near the bottom of the right atrium . This area is easy to reach with the ablation catheter but it may be thick and uneven, making it somewhat difficult to burn all the tissue necessary to eliminate the flutter. The success rate for a first attempt is in the order of 80-90%. The most important risk is the possibility of burning a hole in the heart wall in this region (less than 1%).

42. A. Flutter

43. A. Flutter

44. ??? What if the rate is so fast you can’t tell what they are in????
What is SVT?
What does this do to CO?

45. SVT vs. A.Flutter
Rhythm strip
following Adenosine

46. Atrial Fibrillation Ventricular rate Atrial rate: 350-500
> 100 = uncontrolled <100 = controlled
Atrial rate:
Rhythm: Usually Irregular !
P waves: Not identifiable
P-R interval: Can’t be determined
QRS duration: Normal

47. A. Fib. Electrical Pathways
Atrial fibrillation (often called "A Fib") is most commonly seen in people who have other heart disease (such as heart valve problems, heart attacks, long-standing high blood pressure) or thyroid disease but can be seen in otherwise healthy people without any medical problems. The atria become scarred and irritable and are not able to pass the electrical impulse smoothly like a ripple traveling across a calm water pond. Instead, the electrical impulse breaks up into many smaller ripples that travel around the atria in a very fast, irregular and disorganized manner much like a stormy ocean surface. This makes the atria beat at between beats/minute. A proportion of these impulses travel down the AV node and cause the ventricles to beat quite fast ( beats/min) and very irregularly. The atria beat so fast that blood does not get pumped normally and blood clots tend to form in the atria. Therefore, blood thinners are often prescribed. Atrial fibrillation is often very difficult to control with drugs.

48. A. Fib

49. A. Fib

50. Class I Benefit >>> Risk
Procedure/ Treatment SHOULD be performed/ administered
Class IIa Benefit >> Risk Additional studies with focused objectives needed
IT IS REASONABLE to perform procedure/administer treatment
Class IIb Benefit ≥ Risk Additional studies with broad objectives needed; Additional registry data would be helpful
Procedure/Treatment
MAY BE CONSIDERED
Class III
Risk ≥ Benefit No additional studies needed
Procedure/Treatment should NOT be performed/administered SINCE IT IS NOT HELPFUL AND MAY BE HARMFUL
AHA

51. AHA

52. Wandering Pacemaker Rate: usually slow, but may be 60-100
Rhythm: usually regular, but there is no reason it has to be!
A wandering atrial pacemaker may be a normal phenomenon seen in the very young or the aged and in athletes. Caused by the inhibitory vagal parasympathetic effect of respiration on the SA node and AV junction. IT may also be caused by the administration of digitalis.IT is not usually significant,and treatment is not indicated. When the heart slows excessively, the signs and symptoms, clinical significance, and management are the same as those in symptomatic sinus bradycardia.

53. Wandering Pacemaker
P waves: May vary depending on the origin of the impulse. One P for each QRS (maybe)
P-R interval: Varies as pacemaker wanders between SA node, atrial tissue, and AV node.
QRS duration: Normal
A wandering atrial pacemaker may be a normal phenomenon seen in the very young or the aged and in athletes. Caused by the inhibitory vagal parasympathetic effect of respiration on the SA node and AV junction. IT may also be caused by the administration of digitalis.IT is not usually significant,and treatment is not indicated. When the heart slows excessively, the signs and symptoms, clinical significance, and management are the same as those in symptomatic sinus bradycardia.

54. WAP