APA wk4 EKG lead selection, placement, & ST seg monitor

Question 1

What is an ECG technically speaking?

Answer 1

Technically, it is the net dipole moment of the heart displayed on the vertical axis in millivolts versus the time on the horizontal axis.” (Pardo & Miller, 2018, p. 345)
-As heart depolarizes and repolarizes, electrical currents are dispersed. The current spreads and electrodes detect the activity. (Klabunde, 2012, p. 38)

Question 2

What is a three lead ECG?

Answer 2

Right arm, left arm, and left leg. Potential difference between 2 electrodes is recorded, other lead serves as ground (commonly seen in pediactrics)

Question 3

Between what leads are the majority of dysrhythmias and ischemia detected?

Answer 3

Communication between V5 and lead II

Question 4

what pump does not work properly from ischemia d/t hypoxia

Answer 4

Na+, K+ ATPase Pump (decreased membrane potential)

Question 5

Lateral wall 12-lead

Answer 5

I, aVL, V5, V6

Question 6

Inferior wall 12-lead

Answer 6

II, III, aVF

Question 7

Septal wall 12-lead

Answer 7

V1, V2

Question 8

Anterior wall 12-lead

Answer 8

V3, V4

Question 9

How would you place ECG leads on somebody with situs invertus?

Answer 9

opposite, heart anatomy on opposite side

Question 10

Name waves of ecg and what each one is

Answer 10

P wave: atrial depolarization
ORS complex: ventricular depolarization
T wave: ventricular repolarization

Question 11

PR interval is

Answer 11

time needed for activity to travel from atria to AV

Question 12

QT

Answer 12

time needed for ventricular depolarization and repolarization

Question 13

ST segment

Answer 13

isoelectric period, entire ventricle is depolarized

Question 14

Second degree Mobitz II

Answer 14

“If some P’s don’t get through, then you have a Mobitz II”

Question 15

Second degree Mobitz I (wekenbach)

Answer 15

“Longer, longer, longer, drop… then you have a wekenbach”

Question 16

Third degree AV Block

Answer 16

“Ps and Qs don’t agree, then you have a 3rd degree”

Question 17

what is a common cause of ecg artifact in or?

Answer 17

cautery

Question 18

ST segment represents beginning

Answer 18

of ventricular repolarization

Question 19

What leads must be accounted for in applying diagnostic criteria for myocardial injury?

Answer 19

V2 and V3, otherwise false positives would increase.

Question 20

Changes in ST segment is the result of

Answer 20

myocardial oxygen insufficiency representing injury or infarction (unless false positive)

Question 21

What makes up Lead ll

Answer 21

Right arm(-)to left leg/foot(+)

Question 22

What makes up lead 1

Answer 22

Right arm(-)to left arm(+)

Question 23

Lead III

Answer 23

Left arm(-) to left leg/foot(+)

Question 24

AvF points towards where in einthovens triangle?

Answer 24

Positive Left leg/foot

Question 25

avR points towards?

Answer 25

Positive lead in Right arm

Question 26

avL

Answer 26

Points toward positive lead in left arm

Question 27

Limb leads

Answer 27

II, II, III

Question 28

Augmented leads?

Answer 28

AvF, aVL, aVR

Question 29

Precordial leads?

Answer 29

V1-v6 project out perpendicular to other lead

Question 30

Where is 0 degrees?

Answer 30

Where lead one points to the right

Question 31

Degrees avL?

Answer 31

-30

Question 32

Degrees lead 2?

Answer 32

60

Question 33

Degrees lead 3?

Answer 33

120

Question 34

Degrees avf?

Answer 34

90

Question 35

Mean vector depoliraztion of heart points towards which lead?

Answer 35

Lead 2

Question 36

Precordial leads S wave what inflection and R wave?

Answer 36

Downward, upward

Question 37

Period of ecg that depolarization begins?

Answer 37

ST segment

Question 38

Leads show greatest shift of the ST junction and must be accounted for in applying diagnostic for mi?

Answer 38

V2 v3