unit 5 big test

Question 1

what is cardiac output- definition and formula

Answer 1

how effectively the heart is pumping. stroke volume multiplied by HR

Question 2

what does automaticity refer to

Answer 2

the ability to initiate signals

Question 3

what does irritability refer to

Answer 3

the ability to respond to signals

Question 4

what does conductivity refer to

Answer 4

the ability to pass on a signal

Question 5

what is the path of electricity in the heart

Answer 5

the SA node, intraarterial tracts and Backman’s Bundle, internodal tracts, the AV node, the bundle of His, bundle branches, purkenji fibers

Question 6

what brings the electrical impulse to the LA

Answer 6

Bachman’s bundle

Question 7

what happens to the impulse at the AV node

Answer 7

it pauses, allowing the atria to empty

Question 8

what is the inherent rate of the SA node

Answer 8

60-100

Question 9

what is the inherent rate of the AV junction

Answer 9

40-60

Question 10

what is the inherent rate of the purkenji fiberes

Answer 10

20-40

Question 11

what does the P wave represent

Answer 11

atrial depolarization

Question 12

what does the PR segment represent

Answer 12

atrial systole and the pause at the AV node

Question 13

what does the PR interval represent. where do you measure it?

Answer 13

the whole atrial cycle except repolarization. measure from beginning of P to Q

Question 14

what does the QRS complex represent

Answer 14

ventricular depolarization

Question 15

what does the ST segment represent. where do you measure it

Answer 15

from the end of S to the beginning of T. it represents ventricular systole.

Question 16

what does the QT interval represent

Answer 16

the complete ventricular cycle

Question 17

what does the t wave represent

Answer 17

ventricular repolarization

Question 18

what does the U wave represent

Answer 18

late repolarization, which is not usually seen

Question 19

what does the Ta wave represent

Answer 19

atrial repolarization, not usually seen as it’s hidden in the QRS

Question 20

what is the appropriate measurement for the PR interval

Answer 20

0.12-0.20 seconds

Question 21

what is the appropriate measurement for the QT interval

Answer 21

0.36-0.44 seconds

Question 22

how do you use the 6 second method

Answer 22

count number of QRS in six seconds and multiply by 10

Question 23

how do you use the 1500 method

Answer 23

count the small boxes between QRS complexes and divide 1500 by the number you counted.

Question 24

how do you use the 300 method

Answer 24

count the number of big boxes between QRS and divide 300 by the number of boxes

Question 25

what makes a rhythm regular

Answer 25

when the R-R interval varies by no more than 2 little boxes

Question 26

what happens if the sinus node fails

Answer 26

a lower pacemaker will take over at its slower inherent rate

Question 27

what controls conduction in sinus rhythms

Answer 27

the sympathetic and parasympathetic nervous systems

Question 28

symptoms of decrease cardiac output

Answer 28

pallor (paleness), dizziness (vertigo), chest pain (angina), SOB, confusion, decreased urine output, hypotension, diaphoresis

Question 29

what is atropine used for

Answer 29

accelerates HR in symptomatic bradycardia

Question 30

what are beta blockers used for

Answer 30

to block heart beats. slows the heart in symptomatic tachycardia.

Question 31

what is digitalis used for

Answer 31

to increase the strength of contraction (might also slow the heart)

Question 32

acetaminophen brand name

Answer 32

tylenol

Question 33

ibuprofen brand name

Answer 33

motrin

Question 34

what is the tendency of atrial rhythms

Answer 34

rapid rhythms that usurp the sinus

Question 35

where do impulses originate from in atrial rhythms

Answer 35

one or more irritable foci

Question 36

what shapes can P waves be in atrial rhythms

Answer 36

flat, pointy, notched, biphasic, hidden in T

Question 37

non conducted PACs lack what

Answer 37

PR intervals and QRS complexes

Question 38

what does a T wave that is suddenly different from previous ones indicate

Answer 38

it is probably hiding a P wave

Question 39

what are non conducted PACs

Answer 39

when the premature beat comes before ventricles have repolarized

Question 40

when is there an emergency in sinus arrest

Answer 40

a true pause you miss at least one QRS, emergency comes when the pause lasts greater than 6 seconds

Question 41

what is the affect of Afib on cardiac output

Answer 41

the atria will not contract, so you lose atrial kick (atrial systole), which is responsible for 15-30 of cardiac output

Question 42

where does conduction originate in junctional rhythms

Answer 42

close the the AV node and the bundle of His, but not in the node itself. they can originate in high, low, or mid AV junction.

Question 43

what does retrograde mean

Answer 43

the impulse in a junctional rhythm goes backwards to the atria

Question 44

why is P inverted in junctional rhythms

Answer 44

because electricity is moving up and to the right towards the atria, instead of down and to the left

Question 45

what does it mean if you have an early beat and you see no P wave

Answer 45

if there is no change in the previous T wave, it is a PJC. if the previous T wave looks different than the rest, it is a PAC

Question 46

junctional tachycardia with no visible P wave is called

Answer 46

SVT

Question 47

which rhythms are the most lethal

Answer 47

ventricular. almost all cause symptoms of decreased cardiac output, including cardiac arrest

Question 48

when viewing ventricular rhythms from lead 2, which way will the QRS face

Answer 48

down

Question 49

where do impulses originate in ventricular rhythms

Answer 49

in one or more irritable foci and travel slowly through the ventricular tissue

Question 50

what is the name for two PVCs in a row, PVC occurring every other beat, and PVCs occurring every 3rd beath

Answer 50

couplets, bigeminy, and trigeminy

Question 51

when are PVCs emergencies

Answer 51

when there are more than 6 in a minute, when they are multifocal (mirroring each other), and when R is on T

Question 52

bundle branch blocks

Answer 52

they cause a delay as the impulse travels through the block, causing a wide QRS. P wave will be present.

Question 53

what are pacemakers, what are they used for

Answer 53

devices that send electrical signals to cause depolarization. they are used to maintain a reasonable HR with bradycardia.

Question 54

what is the difference between a fixed rate and demand pacemaker

Answer 54

fixed rates are rarely used. they send signals at a specific interval regardless of the actual rhythm the patient has. demand pacemakers send a signal only if the rate drops below the threshold that is set.

Question 55

what is a captured versus not captured pacemaker spike

Answer 55

captured are spikes that are followed by a P or a QRS. not captured are not

Question 56

what do ST segment changes (elevation, depression) indicate

Answer 56

MI

Question 57

what do flat T waves indicate

Answer 57

hypokalemia

Question 58

what do peaked T waves indicate

Answer 58

hyperkalemia

Question 59

what do pathological Q waves indicate

Answer 59

MI