ECG part 1

Question 1

What are the 3 unique properties of cardiac myocytes?

Answer 1

Automaticity
Rhythmicity
Conductivity

Question 2

What node is the primary pacemaker of the heart and what is it’s inherent discharge rate?

Answer 2

SA node
60-100

Question 3

What inherent discharge rate does the AV node have?

Answer 3

40-60

Question 4

What is the inherent discharge rate of the purkinje fibers?

Answer 4

30-40

Question 5

rank the hierarchy of rhythmicity

Answer 5

Autonomic influence
SA
AV
Purkinje

Question 6

What ion is entering during myocyte depolarization?

Answer 6

Na+

Question 7

What ion is exiting during myocyte repolarization?

Answer 7

K+

Question 8

When a wave of depolarization is moving toward a positive electrode on the skin, the ECG records a simultaneous _______ deflection.

Answer 8

upward

Question 9

When a wave of repolarization is moving toward a positive electrode on the skin, the ECG records a simultaneous _______ deflection.

Answer 9

downward

Question 10

During the P wave, the impulse is spread to the LA via ____________.

Answer 10

Bachmann bundle

Question 11

What is the PR interval?

Answer 11

slight delay that occurs when the spread of depolarization reaches the AV node

Question 12

Does the R or L bundle ranch have an anterior and posterior division?

Answer 12

L

Question 13

QRS complex occurs when the electric impulse reaches ________.

Answer 13

purkinje fibers

Question 14

What is the absolute refractory period?

Answer 14

interval from the beginning of the QRS complex to the apex fo the T wave

Question 15

What 3 things does a single lead assessment look for?

Answer 15

heart rate or rhythm
normal waveforms
abnormal waveforms

Question 16

Single limb monitoring can only accurately assess _____ and _____.

Answer 16

rate
rhythm

Question 17

What is the normal duration of the PR interval?

Answer 17

.12-.20 sec

Question 18

What is the normal duration of the QRS complex?

Answer 18

.06-.10 sec

Question 19

First degree AV block occurs when the impulse is what?

Answer 19

initiated in the SA node but is delayed on the way to the AV node

Question 20

Second degree AV block occurs ____ in the AV junction and prevents what?

Answer 20

high
conduction of some of the impulses through AV node

Question 21

With Mobitz I (Wenckeback), as _____ increases, _______ will eventually be dropped

Answer 21

PR interval
QRS complex

Question 22

Mobitz II has intermittent non-conducted P waves _________ progressive prolongation of PR interval.

Answer 22

without

Question 23

What should remain fine with Mobitz II?

Answer 23

CO

Question 24

With 3rd degree AV block, what happens with the atria and ventricles?

Answer 24

they fire at their own inherent rate

Question 25

How is a first degree block treated?

Answer 25

benign and usually not treated

Question 26

How is a second degree block treated?

Answer 26

either no treatment or a pacemaker (if they have too many drops)

Question 27

What are 2 causes of 3rd degree AV block?

Answer 27

MI degeneration of the conducting system

Question 28

What is the treatment for 3rd degree block?

Answer 28

permanent pacemaker placement