Cardiac rhythm monitors & equipment

Question 1

Which pathway depolarizes the left atrium?
a. Thorel tract
b. Bachmann bundle
c. Kent bundle
D. Wenckebach tract

Answer 1

b. Bachmann bundle

Question 2

There are _________ internodal tracts that travel from the SA node to the AV node

Answer 2

3:
anterior internodal tract
middle internodal tract
posterior internodal tract

Question 3

The anterior internodal tract gives rise to the

Answer 3

Bachmann bundle

Question 4

The middle internodal tract gives rise to the

Answer 4

Wenckebach tract

Question 5

The posterior internodal tract gives rise to the

Answer 5

Thorel tract

Question 6

Conduction velocities of the cardiac conduction pathway from slowest to fastest are

Answer 6

AV node
SA node
myocardial muscle cells
His bundle
Bundle branches
Purkinje fibers

Question 7

There’s a band of connective tissues that electrically isolates the

Answer 7

atria from the ventricles making the AV node the gatekeeper of electrical impulses into the ventricle

Question 8

The SA & AV nodes conduct at

Answer 8

0.02-0.10 m/sec

Question 9

The myocardial muscle cells conduct at

Answer 9

0.3-1 m/sec

Question 10

The His bundle, bundle branches, and Purkinje fibers conduct at

Answer 10

1-4 m/sec

Question 11

Conduction velocity is a function of

Answer 11

resting membrane potential
amplitude of the action potential
rate of change in membrane potential during phase O

Question 12

Conduction velocity is affected by:

Answer 12

ANS tone
Hyperkalemia induce closure of fast Na+ channels
Ischemia
acidosis
antiarrhythmic drugs

Question 13

The James fiber accessory pathway is

Answer 13

atrium to AV node

Question 14

The Atrio-hisian fiber accessory pathway is

Answer 14

atrium to His bundle

Question 15

The Kent’s bundle accessory pathway is

Answer 15

atrium to ventricle

Question 16

The Mahaim bundle accessory pathway is

Answer 16

AV node to ventricle

Question 17

Key components of the EKG include

Answer 17

P wave
PR-interval
QRS complex
ST segment
T wave

Question 18

What happens at the P wave?

Answer 18

atrial depolarization begins

Question 19

What happens at the PR interval?

Answer 19

atrial depolarization complete

Question 20

What happens at the QRS complex?

Answer 20

atrial repolarization + ventricular depolarization

Question 21

What happens at the ST-segment?

Answer 21

ventricular depolarization complete

Question 22

What happens at the T wave?

Answer 22

ventricular repolarization begins

Question 23

___________ can cause PR-interval depression

Answer 23

Pericarditis

Question 24

Peaked T waves can be caused by

Answer 24

myocardial ischemia
hyperkalemia
left ventricular hypertrophy
intracranial bleeding

Question 25

Q waves suggest myocardial infarction if the amplitude is _____________, duration is _________-, or depth is ___________

Answer 25

greater than 1/3rd of the R wave; duration is greater than 0.04 seconds, or depth is greater than 1 mm

Question 26

What is used as a reference point for measuring ST elevation and depression?

Answer 26

the PR segment b/c it is an isoelectric line

Question 27

By measuring the ______, we can quantify the amount of ST elevation and depression. As a rule, changes greater than _____-- or less than _________ are significant.

Answer 27

J point; +1.0 or less than -1.0

Question 28

Hypokalemia causes an

Answer 28

increased PR interval, increased QT interval, T wave flattening and a U wave

Question 29

Hyperkalemia causes

Answer 29

peaked T waves, P wave flattening, PR prolongation, QRS prolongation, sine wave pattern, and ventricular fibrillation

Question 30

Hypercalcemia is associated with

Answer 30

a short QT interval

Question 31

Hypocalcemia is associated with a

Answer 31

long QT interval

Question 32

Hypermagnesemia is associated with

Answer 32

heart block and cardiac arrest

Question 33

Hypomagnesemia is associated with a

Answer 33

long QT interval (risk of torsades de points)

Question 34

T wave points in opposite direction of QRS if repolarization is prolonged by

Answer 34

myocardial ischemia bundle branch block

Question 35

This may occur with hypothermia

Answer 35

Osborn wave- small positive deflection immediately after the QRS complex

Question 36

Duration of the P wave is

Answer 36

0.08-0.12

Question 37

Duration of the PR interval is

Answer 37

0.12-0.20

Question 38

Duration of the Q wave is

Answer 38

<0.04

Question 39

Duration of the QRS complex is

Answer 39

<0.10

Question 40

Duration of the QTC interval is

Answer 40

<0.47

Question 41

The ____________ is the average current flow of all action potentials at a given point in time

Answer 41

The mean electrical vector

Question 42

A positive deflection in the EKG occurs when the vector of depolarization travels

Answer 42

towards positive electrode

Question 43

A negative deflection in the EKG occurs when the vector of depolarization travels

Answer 43

away from a positive electrode

Question 44

___________________ on the EKG occurs when the vector of depolarization travels perpendicular to a positive electrode

Answer 44

A biphasic deflection

Question 45

The bipolar leads include

Answer 45

I, II, III

Question 46

The limb leads include

Answer 46

aVR, aVL, aVF

Question 47

The precordial leads include

Answer 47

V1-V6

Question 48

Inferior heart leads include

Answer 48

II, III, aVF

Question 49

Inferior heart leads correspond to the

Answer 49

right coronary artery

Question 50

Left lateral heart leads include

Answer 50

I, aVL, V5, V6

Question 51

Left lateral heart leads correspond to the

Answer 51

circumflex artery

Question 52

Anterior heart leads include

Answer 52

V1-V4

Question 53

Anterior heart leads correspond to the

Answer 53

left coronary artery