Cardiac rhythm monitors & equipment 3

Question 1

With 1st degree heart block, the PR interval is

Answer 1

> 0.20 sec.

Question 2

1st degree heart block is usually

Answer 2

asymptomatic (no treatment required)

Question 3

2nd degree heart block consists of

Answer 3

Mobitz type 1 & 2

Question 4

Mobitz type 1 is characterized by the

Answer 4

PR interval becomes progressively longer with each cycle, but the last P wave does not conduct to the ventricles

Question 5

Mobitz type 1 is usally

Answer 5

asymptomatic; if symptomatic treat with atropine

Question 6

Mobitz type 2 is characterized by

Answer 6

some P’s conduct to the ventricles while others don’t (there is usually a set ratio of 2:1 or 3:1)

Question 7

With Mobitz type 2, patients are

Answer 7

symptomatic

Question 8

Treatment for Mobitz type 2 is

Answer 8

pacing

Question 9

3rd degree heart block is characterized by

Answer 9

the atria & ventricles have their own rates (AV dissociation)

Question 10

Treatment for 3rd degree heart block is

Answer 10

a pacemaker or isoproterenol

Question 11

What is the saying for 1st degree heart block?

Answer 11

if r is far from p then you have a first degree

Question 12

The etiology of 1st degree heart block is

Answer 12

age related degenerative changes
CAD
digoxin
amiodarone

Question 13

The saying for 2nd degree heart block type 1 is

Answer 13

“longer, longer, longer, drop, then you have a Wenckebach”

Question 14

Etiology for 2nd degree heart block type 1 is

Answer 14

structural conduction defect
myocardial injury/infarction
beta-blockers
CCBs
digoxin
sympatholytic agents

Question 15

The saying for Mobitz type 2 is

Answer 15

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

Question 16

Etiology for Mobitz type 2 is

Answer 16

a structural conduction defect or infarction

Question 17

___________ has a high risk for progressing to complete heart block

Answer 17

Mobitz type 2

Question 18

The saying for 3rd degree heart block is

Answer 18

If “P”s and “Q”s don’t agree then you have a 3rd degree

Question 19

3rd degree heart block can often lead to

Answer 19

CHF due to decreased HR & CO
Stokes-Adams attack= decreased CO–> decreased cerebral perfusion–> syncope

Question 20

Antiarrhythmic medications can be divided into

Answer 20

4 classes

Question 21

Class 1 drugs

Answer 21

inhibit fast sodium channels

Question 22

Examples of class 1 drugs include

Answer 22

lidocaine, procainamide, & phenytoin

Question 23

Class 2 drugs

Answer 23

decrease the rate of phase 4 depolarization

Question 24

Examples of class 2 drugs include

Answer 24

beta-blockers

Question 25

Class 3 drugs

Answer 25

inhibit potassium ion channels (prolongs phase 3 repolarization)

Question 26

Examples of class 3 drugs include

Answer 26

amiodarone & bretylium

Question 27

Class 4 drugs

Answer 27

inhibit slow calcium channels and slow the conduction velocity through the AV node

Question 28

Examples of class 4 drugs include

Answer 28

verapamil & diltiazem

Question 29

Adenosine works by

Answer 29

slowing conduction through the AV node

Question 30

The dose range of adenosine is

Answer 30

3 mg-12 mg
peripheral: 6 mg, then 12 mg
central: 3 mg, then 6 mg

Question 31

Adenosine is useful for

Answer 31

supraventricular tachycardia
WPW with a narrow QRS

Question 32

_______________ can cause bronchospasm in asthmatic patients

Answer 32

Adenosine

Question 33

The Class 1 of antiarrhythmic medications is further divided into

Answer 33

1A- moderate depression of phase 0
1B- weak depression of phase 0
1C-strong depression of phase 0

Question 34

Lidocaine & phenytoin are considered

Answer 34

Class 1B antiarrhythmics

Question 35

Flecainide & Propafenone are considered

Answer 35

Class 1C antiarrhythmics

Question 36

Quinidine, procainamide, & disopyramide are considered to be

Answer 36

Class 1A antiarrhythmics

Question 37

Wolff-Parkinson-White syndrome is associated with:
a. atrial reentry
b. SA nodal reentry
c. atrial-ventricular reentry
d. ventricular reentry

Answer 37

c. atrial-ventricular reentry

Question 38

The most common cause of tachyarrhytmias are

Answer 38

reentry pathways

Question 39

In the normal conduction pathway, the cardiac impulse moves

Answer 39

in one direction: SA node–> AV node–> His bundle–> bundle branches–> purkinje fibers

Question 40

The cardiac impulse cannot move

Answer 40

backward, b/c all of the tissues behind the impulse remain in the absolute refractory period

Question 41

When a reentry pathway develops, a single cardiac impulse can

Answer 41

move backward and excite the same part of the myocardium over and over creating a reentry tachyarrhythmia

Question 42

The reentry circuit can be broken by

Answer 42

slowing the conduction velocity through the circuit or increasing the refractory period of the cells at the location of the unidirectional block

Question 43

Conditions that increase the risk of reentry tachyarrhythmias include

Answer 43

left atrial dilation
ischemia
hyperkalemia
epinephrine

Question 44

How can mitral stenosis cause a reentry pathway?

Answer 44

conduction must occur over a longer distance

Question 45

How can ischemia cause a reentry pathway?

Answer 45

conduction velocity through the affected region is too slow

Question 46

How can epinephrine cause a reentry pathway?

Answer 46

it shortens the duration of the refractory period