Basics of EKG part I

Question 1

each small square on ECG paper = how many seconds in duration and what amplitude

Answer 1

• 0.04 sec
• 0.1 mV = 1mm

Question 2

five small squares or one large box = what duration

Answer 2

• 0.2 seconds in duration

Question 3

What causes P wave

Answer 3

• produced by
  
  • initiation of impulse in SA node
  • depolarization of RA and LA
  • impulse passing through AV junction

Question 4

duration of P wave should be

Answer 4

0.06-0.10 seconds

Question 5

PR interval consists of what segments? normal time for PR interval is

Answer 5

• start of P wave and ends at start of QRS complex
• 0.12-0.20

Question 6

PR segment consists of what segments?

Answer 6

• isoelectric line between end of P wave and start of QRS complex

Question 7

differentiate between Q, R, and S waves in terms of deflection

Answer 7

• Q wave: first negative deflection following PR segment
• R wave: first positive deflection following Q wave
• S wave: first negative deflection following R wave

Question 8

normal QRS duration is

Answer 8

0.06-0.11 seconds

Question 9

ST segment consists of what on ECG

Answer 9

• flat line that follows QRS complex

Question 10

Where is the J point

Answer 10

where the QRS complex meets the ST segment

Question 11

QT internval consists of what on ECG

Answer 11

• distance from onset of QRS complex until the end of T wave

Question 12

QT internval is a measure of

Answer 12

• time of ventricular depolarization and repolarization

Question 13

normal duration of QT internval

Answer 13

• 0.36-0.44 seconds

Question 14

aVR augmented lead points in direction of and views what aspect of the heart

Answer 14

• Right arm positive
• views base of heart: atria and great vessels

Question 15

aVL augmented lead points in direction of ​ and views what aspect of the heart

Answer 15

• Left arm positive
• views lateral wall of left ventricle

Question 16

aVF augmented lead points in direction of ​ and views what aspect of the heart

Answer 16

• Left leg positive
• views inferior wall of inferior left ventricle

Question 17

are the precordial (chest) leads positive or negative

Answer 17

all positive

Question 18

List the placement of V1, V2, V3, V4, V5, and V6 on chest

Answer 18

• V1: 4th ICS on the right of sternum
• V2: 4th ICS on the left of sternum
• V3: halfway between V2 and V4
• V4: 5th ICS in mid clavicular line
• V5: anterior axillary line, same horizontal plane as V4
• V6: midaxillary line, same horizontal plane as V4

Question 19

What are the modified chest leads

Answer 19

• MCL 1 and MCL 6
  
  • provide continuous cardiac monitoring
  • used in ER, telemetry, and ICU
• place positive electrode in same position as V1 or V6

Question 20

List the leads that assess the anterior portion of the heart

Answer 20

• V1-V4

Question 21

List the leads that assess the lateral portion of the heart

Answer 21

• I
• aVL
• V5-V6

Question 22

List the leads that assess the inferior portion of the heart

Answer 22

• II
• III
• aVF

Question 23

How can you calculate the heart rate using a 6 second interval ECG

Answer 23

• multiply by 10 the number of QRS complexes found in a 6 second portion of ECG tracing

Question 24

What is the method of determining rate of ECG in which you find an R wave located on or near a bold and then find the next consecutive R wave. Bold line the 2nd R wave falls on represents heart rate

Answer 24

• 300, 150, 100, 75, 60, 50 method

Question 25

When using 300, 150, 100, 75, 60, 50 method, what do you do if second R wave does not fall on a bold line (quick and dirty method)

Answer 25

* heart rate is approximated * ex: falls between 75 and 60 BPM bold lines, then HR lies in between those BPM

Question 26

When using the 300, 150, 100, 75, 60, 50 method, what is the acceptable way to determine rate when the R-R interval falls between large boxes

Answer 26

* ex: if rate is between 100-75, there are 25 numbers in between them, so each small box can represent a heart rate of 5 (25/5 small boxes) * ex: if rate is between 75-60, there are 15 numbers between them, so each small box can represent a heart rate of 3 (15/5)

Question 27

can the 300, 150, 100, 75, 60, 50 method be used with irregular rhythms?

Answer 27

NO

Question 28

can the 1500 method to determine rate on ECG be used with irregular rhythms

Answer 28

NO

Question 29

What is the 1500 method

Answer 29

* count the number of **small squares** between two consecutive R waves and **divide 1500** by that number * \*\* most accurate

Question 30

normal HR lies between

Answer 30

* 60-100 bom * \< 60 bpm -\> bradycardia * \> 100 bpm -\> tachycardia

Question 31

how can you determine if rhythm is regular or irregular? What are the methods?

Answer 31

* if the distance of R-R intervals and P-P intervals is the same -\> regular * methods * caliper method * paper and pen method * counting the small squares method

Question 32

What is the Caliper method to determine heart rate regularity

Answer 32

1. position one point of caliper on a starting point 2. open caliper until the point is positioned on the next R wave or P wave 3. rotate caliper across to peak of the next consecutive (3rd) P wave or R wave

Question 33

What is a wandering atrial pacemaker? what affect does it have on rhythm

Answer 33

* pacemaker changes location from site to site producing a slighly irregular rhythm

Question 34

What is paroxysmal tachycardia

Answer 34

* a normal heart rate that suddently accelerates to a rapid rate producing an irregularity in the rhythm

Question 35

what is patterned irregularity

Answer 35

* irregularity that repeats itself in a cyclic fashion

Question 36

What is a irregularly irregular rhythm? this is seen in what condition

Answer 36

* no pattern to irregularity * typically seen in atrial fibrillation