Analyzing a Rhythm Strip Sinus Arrhythmias

Question 1

What does the horizontal and vertical axis represent on EKG paper?

Answer 1

H: Time seconds
V: Voltage (mV) mm

Question 2

How fast does the EKG paper move?

Answer 2

25mm/sec

Question 3

What does 1 “small box” represent

Answer 3

0.04 seconds

Question 4

What does 1 “Large box” represent?

Answer 4

0.20 seconds

Question 5

What do 5 “Large boxes” represent?

Answer 5

1 second

Question 6

What do 30 large boxes represent

Answer 6

6 seconds

Question 7

Where does the cardiac rate normally come from?

Answer 7

The SA node (60-100bpm)

Question 8

Do cardiac cells have the ability to pace the heart?

Answer 8

Yes, if needed they can

Question 9

What are automaticity Foci?

Answer 9

1. Potential pacemarkers that are capable of pacing the heart in emergency situations (ectopic Foci)
2. Atria, AV junction, and the ventricles

Question 10

If the SA node fails what is the next likely automaticity center to assume cardiac pacemaker activity?

Answer 10

Atria

Question 11

If there was an EKG with a rate of 35 BPM where is the rate originating from?

Answer 11

Ectopic Pacemaker (ventricles)

Question 12

What are the 5 steps to analyzing an EKG?

Answer 12

1. Rate
2. Rhythm
3. Axis
4. Hypertrophy
5. Infarction
   *Only 1 and 2 can be analyzed on a rhythm strip

Question 13

What does the rate of a rhythm strip represent?

Answer 13

1. Heart rate will always refer to ventricular rate unless atrial and ventricular rate differ

Question 14

What are the methods for determining rate?

Answer 14

1. “6 second method”
2. 300, 150, 100, 75, 60, 50
3. Precise calculations

Question 15

When would the 300, 150,100,75,60,50 method be used?

Answer 15

1. For normal and fast rates
   *not accurate if the rate is irregular

Question 16

When would the 6 second method be used?

Answer 16

1. For bradycardia or irregular rhythms

Question 17

When would you NOT use precise calculation?

Answer 17

1. For irregular rhythms

Question 18

How to do the “precise calculation” method?

Answer 18

1. Count the number of small squares between the peaks of the R-R
2. 1500/# of small squares

Question 19

What are the 10 points to consider when analyzing a rhythm strip?

Answer 19

1. Is the rhythm fast or slow?
2. Is the rhythm regular or irregular
3. Do you see any P waves?
4. Are all the P waves the same?
5. Does each QRS complex have a P wave
6. Is the PR interval constant?
7. Are the P waves and QRS complexes associated with one another?
8. Are the QRS complexes narrow or wide?
9. Are the QRS complexes grouped or not grouped
10. Are there any dropped beats?

Question 20

What are dropped beats?

Answer 20

P wave with no QRS

Question 21

What is an irregular rhythm?

Answer 21

R-R greater than 3 boxes
>0.12 seconds

Question 22

What does the wave of depolarization represent?

Answer 22

The movement of conduction from the SA node down to the heart

Question 23

What is the normal size of a P-wave?

Answer 23

Width: <0.12 seconds
Height: <2.5mm

Question 24

When are P waves considered “sinus”

Answer 24

1. 1:1 P to QRS ratio
2. All P waves are identical in size, shape and position

Question 25

How to measure the PR interval?

Answer 25

1. Measure from the beginning of P wave as it leaves baseline to beginning of the QRS complex

Question 26

What is the normal size of the PR interval?

Answer 26

0.12 to 0.20 seconds (3-5 small blocks)

Question 27

How to measure the QRS duration

Answer 27

1. Measure from the beginning QRS complex until the ST segment begins

Question 28

What is the normal QRS duration

Answer 28

0.06 to 0.11 seconds (greater than 3 small boxes is abnormal)

Question 29

What is the J-point?

Answer 29

Place where QRS ends and ST segment begins

Question 30

Where would J-Point elevation be shown?

Answer 30

In patient with early REPOLE, LVHH with strain and pericarditis

Question 31

When would a Q wave be abnormal?

Answer 31

1. > (or equal to) 0.03 seconds or wider (1 small box or larger) 2. Its height is > (or equal to) 1/3 height of the R wave

Question 32

What happens during the ST segment?

Answer 32

1. Electrically silent period between ventricular depolarization and repolarization

Question 33

Why is the T-wave an upward deflection?

Answer 33

Bc it is a negative wave traveling away from the electrode

Question 34

What can symmetric T waves be a sign of?

Answer 34

Ischemia

Question 35

What does the QT interval represent?

Answer 35

Ventricular systole (waiting to repolarize)

Question 36

What is an abnormal QT duration?

Answer 36

>10 small boxes (0.4 seconds)

Question 37

What are Sinus Arrhythmias?

Answer 37

1. Originate from the sinus node Can be *sinus tachycardia *sinus bradycardia *sinus arrest or block

Question 38

What are P-Mitrale?

Answer 38

1. When the P waves are greater than 0.12 seconds in leads (I and II) and notched (m-shaped) 2. Seen in left atrial enlargement

Question 39

What causes the notching in P-mitrale?

Answer 39

1. Caused by the prolonged conduction times required to transmit the impulse through the enlarged left atrium

Question 40

What does the notching represent?

Answer 40

The right then left atria depolarization

Question 41

What is the most common cause of P-mitrale?

Answer 41

Severe mitral valve disease *mitral stenosis leads to left atrial hypertrophy to overpower stenotic valve

Question 42

What is a sinus pause?

Answer 42

An umbrella term of disorders in which there is a sudden failure of the SA node to initiate or conduct impulse 1. Sinus exit block 2. Sinus arrest

Question 43

Are premature beats included in the calculation of heart rate?

Answer 43

No

Question 44

What are the rules for diagnosing multiple rhythms?

Answer 44

1. Describe the basic underlying rhythm first 2. Then describe the additional information