unit 5

Question 1

what is cardiac output? what is the formula?

Answer 1

how effectively the heart is pumping. it is stroke volume multiplied by heart rate

Question 2

what is the cardiac conduction system, and how do pacemaker cells function?

Answer 2

it is a pathway of speciailized cells that create and conduct electrical impulses. all of these cells are pacemaker cells, which can initiate, respond to, and pass on signals

Question 3

what is the pathway of electricity in the heart

Answer 3

the SA node, the internodal tracks, Bachman’s bundle, the AV node, the bundle of His, the bundle branches, and the purkenji fibers

Question 4

what do the internodal tracts and bachmans bundle do

Answer 4

they bring the impulse to the left atrium

Question 5

what happens to the impulse when it reaches the AV node

Answer 5

it pauses to allow the atria to empty

Question 6

where do the bundle branches take the impulse

Answer 6

the the ventricles

Question 7

what is the inherent rate of the SA node

Answer 7

60-100 BPM

Question 8

what is the AV junction rate

Answer 8

40-60. the AV junction includes the AV node and the Bundle of His, and serves to unite the electrical systems of the ventricles and atria

Question 9

what is the ventricle rate

Answer 9

20-40

Question 10

where do all normal rhythms originate

Answer 10

the SA node, they are referred to as sinus rhythms

Question 11

what is an arrhythmia

Answer 11

a rhythm that originates from any other pacemaker. always abnormal

Question 12

what is the isoelectric line

Answer 12

the baseline. you use the PR segment as the isoelectric line

Question 13

intervals include

Answer 13

segments (flat portions) and waves

Question 14

what do complexes contain

Answer 14

mutiple waves

Question 15

what does one heartbeat contain

Answer 15

a p-qrs-t sequence

Question 16

what is the most common lead to evaluate for rate and rhythm

Answer 16

lead 2

Question 17

what is the morphology of the waves? what happens to morphology if you change viewing leads

Answer 17

shape, it will change

Question 18

what does the p wave represent. what should it look like

Answer 18

atrial depolarization. round, symmetrical upright, and small

Question 19

what does the PR interval represent

Answer 19

the artial cycle, not including repolarization

Question 20

what does the PR segment represent

Answer 20

atrial systole and the pause at the AV node

Question 21

what does the QRS complex represent

Answer 21

ventricle depolarization

Question 22

what does the ST segment represent

Answer 22

ventricular systole

Question 23

what does the T wave represent. what should it look like

Answer 23

ventricular repolarization. broad, round, leaning towards QRS

Question 24

what does the QT interval represent

Answer 24

the complete ventricular cycle

Question 25

what is the purpose of the R-R interval

Answer 25

it is measured to determine rate and regularity of rhythm

Question 26

what does the U wave represent. what should it look like

Answer 26

late repolarization, not usually seen. shallow, broad, and rouded

Question 27

waht does the Ta wave represent.

Answer 27

atrial repolarization. it is usually hidden in the QRS.

Question 28

how do you measure the PR interval and what should it be

Answer 28

from the beginning of P to the beginning of the QRS complex. should be 3-5 small boxes, which is 0.12-0.20 seconds.

Question 29

how do you measure the QRS interval and what should it be

Answer 29

from the beginning to end of the QRS, should be less than 0.12 seconds (3 small boxes).

Question 30

how do you measure the QT interval

Answer 30

from the beginning of the QRS to the end of the T wave. should be 0.36-0.44 seconds, or 9-11 small boxes

Question 31

how many boxes is 1 second equivalent to

Answer 31

5 big boxes, 25 small

Question 32

how many seconds is 1 big box

Answer 32

0.20

Question 33

how many seconds is 1 small box, how many milivolts

Answer 33

0.04 seconds, 0.1 milivolts

Question 34

what is heart rate

Answer 34

the number of QRS complexes recorded in BPM

Question 35

what is the 6 second method

Answer 35

the fastest method but the least accurate, and the only one that can be used on irregular rhythms. count the number of QRS complexes in 6 seconds and multiply by 10.

Question 36

what is the 1500 method

Answer 36

the most accurate. count the small boxes between QRS complexes and divide 1500 by that number. to find the number of small boxes quicker, count the number of big boxes, multiply by 5, and add the remaining small boxes on either side.

Question 37

what is the 300 method

Answer 37

the middle accuracy, best with regular rhythms. find a QRS that is on a dark line and count the number of big boxes between the next QRS. divide 300 by the number of big boxes

Question 38

what is a regular rhythm

Answer 38

a R-R interval that varies by no more than 1-2 little boxes

Question 39

what is a regular but interrupted rhythm

Answer 39

the underlying rhythm is regular, but an eptopic beat breaks it up, meaning either a pause or a beat that is too fast.

Question 40

what is a irregular rhythm

Answer 40

R-R varies throughout the tracing

Question 41

what is regularly irregular

Answer 41

it doesnt meet the defintion of regular but there is a clear repeating pattern

Question 42

what are the 6 basic steps in EKG analysis

Answer 42

determine the rate in BPM, examine for regularity, determine if the P wave is present and uniform, measure the PR interval, measure the QRS interval, identify the rhyhtm