EKG Shit

Question 1

myocardial automaticity

Answer 1

cells can contract on own without nervous system stimulation

Question 2

myocardial excitability

Answer 2

any cell within myocardium can create impulses and become excited

Question 3

myocardial conductivity

Answer 3

one cell can send impulse to other cells and propagate through myocardium even outside natural conductive pathways

Question 4

myocardial contractility

Answer 4

cells can shorten and lengthen during contraction/relaxation

Question 5

cardiac action potential phase 1 ion & action

Answer 5

Na+ enters, upstroke

Question 6

cardiac action potential phase 2 ion & action

Answer 6

Ca2+ enters, plateau

Question 7

cardiac action potential phase 3 ion & action

Answer 7

K+ exits, repolarization

Question 8

cardiac action potential phase 4 is…

Answer 8

resting potential

Question 9

unipolar limb leads: right arm

Answer 9

aVr

Question 10

unipolar limb leads: left arm

Answer 10

aVL

Question 11

unipolar limb leads: left leg

Answer 11

aVf

Question 12

P wave: what happens?

Answer 12

atria depolarization

Question 13

QRS wave: what happens?

Answer 13

depolarization of ventricles

Question 14

T wave: what happens?

Answer 14

repolarization of myocardium

Question 15

PR interval: what happens?

Answer 15

electrical impulse in AV node and waiting (electrical silence, atria are contracting)

Question 16

ST interval: what happens?

Answer 16

electrical silence (ventricles are contracting)

Question 17

EKG small boxes per minute

Answer 17

1500

Question 18

EKG large boxes per minute

Answer 18

300

Question 19

EKG one small box equals

Answer 19

0.04 seconds

Question 20

EKG one large box equals

Answer 20

0.20 seconds

Question 21

EKG small boxes in a large box

Answer 21

25 (5x5)

Question 22

six steps of EKG interpretation

Answer 22

1. determine heart rate
2. determine heart rhythm
3. look at P-wave
4. measure PR interval
5. measure QRS duration
6. interpret rhythm

Question 23

EKG X and Y axes

Answer 23

X: time (determine heart rate)
Y: voltage amplitude (shows adequate voltage NOT strength of contraction)

Question 24

heart rate determination tips

Answer 24

HR abnormal? count beats over six seconds

HR normal? measure from R wave to R wave

Question 25

expected PR interval

Answer 25

0.12 - 0.2

Question 26

expected QRS interval

Answer 26

0.06 - 0.1

Question 27

EKG interp: a fib

Answer 27

1. HR < 100 (if >100, a fib with rapid ventricular response RVR)
2. irregularly irregular
3. p wave replaced with fibbies
4. can’t measure PR
5. QRS 0.06 - 0.1 (abnormality in atria!!)

Question 28

EKG interp: a flutter

Answer 28

1. HR < 100 (>100 flutter w/ RVR)
2. irregularly irregular
3. p wave replaced with SAW TOOTH FLUTTER
4. can’t measure PR
5. QRS 0.06 - 0.1 (abnormality in atria!!)

Question 29

EKG interp: atrial paced

Answer 29

1. HR can vary
2. regular
3. pacer spike BEFORE P wave
4. PR 0.12 - 0.2
5. QRS 0.06 - 0.1

Question 30

EKG interp: ventricular paced

Answer 30

1. HR typically fixed (can vary)
2. regular
3. p wave may be absent
4. PR absent OR > 0.2
5. QRS > 0.12 with abnormal T wave

pacer spike BEFORE upsidedown QRS

Question 31

EKG interp: AV paced

Answer 31

1. HR fixed
2. regular
3. pacer spike before P wave
4. PR usually > 0.2
5. QRS upsidedown and > 0.2

Question 32

EKG interp: v tach

Answer 32

1. HR > 150
2. regular
3. no p waves
4. no PR interval
5. QRS > 0.12

LETHAL ARRHYTHMIA

Question 33

EKG interp: torsade depointes

Answer 33

electrical chaos!!!!

1. HR > 150
2. irregular
3. no P waves
4. no PR interval
5. QRS variable morphology

LETHAL ARRHYTHMIA

Question 34

EKG interp: v fib

Answer 34

1. no discernible HR
2. irregular
3. no P waves
4. no PR
5. no QRS