Physiology Of The Heart-Ecg & Vcg

Front 1

The _____ provides only partly information about mechanical events in the heart.

Back 1

ECG

Front 2

ECG deflections correspond to specific _______ events in the heart.

Back 2

electrical

Front 3

The actual _____ equals the main potential difference pointing in a certain direction.

Back 3

vector

Front 4

The Einthoven ECG can not record ______ but only its projections to the three planes.

Back 4

actual vector

Front 5

What is meant by the reversal of an actual vector?

Back 5

The vector of the Einthoven ECG can be reconstructed from its projections (with at least two out of the three).

Front 6

What is meant when an actual vector can change its value & direction progressively during the cardiac cycle?

Back 6

value=(size=electrical potential)
direction=(angle between the horizontal lead I & the vector)

Front 7

The depolarization of the atria & ventricle, as well as the repolarization of the ventricle begib & end with _____ millivolts.

Back 7

zero

Front 8

Accordingly the vector & all 3 projections of the EIN ECG begin & end with _____ millivolts.

Back 8

zero

Front 9

During an AP triggered by the SA Node, the number of muscle fibers & the direction the depolarization take _______.

Back 9

vary

Front 10

When the SA node triggers an AP, a wave of _______ runs through the entire heart.

Back 10

depolarization

Front 11

The strength of the electrical signal generated by a depolarization depends directly on the number of ________ cells.

Back 11

depolarizing

Front 12

The max. measured potential can not ______ the max. generated potential.

Back 12

exceed

Front 13

The measured potential can be much _______ than the generated potential.

Back 13

lower

Front 14

Why can a measured potential be generated but not measured?

Back 14

B/c the direction of the depolarization is in relation to the direction of the measurement.

Front 15

Ionic differences in the ECF can be measured as electrical potential only during ______ & _______.

Back 15

repolarization & depolarization

Front 16

Vertical orientation of the heart views ______.

Back 16

nothing

Front 17

Angular orientation of the heart views ________.

Back 17

part of the length

Front 18

Parallel orientation of the heart views ______.

Back 18

full length

Front 19

The viewed size of an item depends on the viewed _______.

Back 19

angle

Front 20

The recorded electrical potential depends on what?

Back 20

On the location of the depolarization & placement of the electrodes.

Front 21

What is a vector?

Back 21

It is an arrow on the heart
that represents an electrical potential generated by a progressing de/repolarization in the heart.

Front 22

Looking st the heart from different positions results in the measurement of three different values of the same______.

Back 22

vector

Front 23

In the _________ method three electrodes are connected to the arms & one foot, creating an almost equilateral triangle.

Back 23

Einthoven

Front 24

_________ w/ the heart in the center provides an equal distance for an electrical current to each of the electrodes, providing optimum measuring conditions.

Back 24

Einthoven triangle

Front 25

A _______ electrode is connected to the right foot.

Back 25

fourth electrode

Front 26

What is the purpose of the fourth electrode.

Back 26

It is grounded in order to eliminate any external artificial electrical signals.

Front 27

What happens if you don't used the 4th electrode?

Back 27

The body would act as an antenna & pick up larger signals than the targeted cardiac signal.

Front 28

Which vector represents the main potential difference in the heart?

Back 28

cardiac

Front 29

What does a plane refer to as it pertains to a vector?

Back 29

The orientation of pairs of electrodes in relation to the heart.

Front 30

What does the orientation of a plane determine?

Back 30

how much of the cardiac vector is measured.

Front 31

Electrodes 1 & 2 & the first plane are horizontally placed this called Lead ___.

Back 31

1

Front 32

Electrodes 1 & 3 creates another planed which is called ______

Back 32

Lead 2

Front 33

The recorded size of the vector produced by lead II is smaller than Lead ___.

Back 33

Lead 1

Front 34

Using electrodes 2 & 3 creates a third plane called ______.

Back 34

Lead III

Front 35

What influences the ECG in animals?

Back 35

different sizes & shapes

Front 36

A _____ signal can occur if leads are incorrectly placed.

Back 36

inverted

Front 37

How is Lead 1 of the Eiththoven triangle connected?

Back 37

(-)rt. forelimb --> (+)lft. forelimb

Front 38

How is Lead 2 of the Eiththoven triangle connected?

Back 38

(-)rt. forelimb --> (+)lft. hindlimb

Front 39

How is Lead 3 of the Eiththoven triangle connected?

Back 39

(-) left forelimb ---> (+) left hindlimb

Front 40

Using the Einthoven method what does each lead record?

Back 40

ECG

Front 41

Why do the 3 recordings of the Einthoven method differ.

Back 41

Due to the placement of leads in 3 different places.

Front 42

What is the difference between the Einthoven & Goldberger method?

Back 42

The Goldberger method of ECG recording provides stronger signals

Front 43

______ of the ECG is responsible for the depolarization of the atria.

Back 43

P Wave

Front 44

______ of the ECG is responsible for the depolarization of the AV node & bundle of his.

Back 44

PQ segment

Front 45

________ is the time from the beginning of the atrial depolarization to the beginning of the ventricular depolarization

Back 45

PQ interval

Front 46

A _____ is one positve or negative deflection.

Back 46

wave

Front 47

____ equals the distance/time between 2 waves

Back 47

segment

Front 48

_______ consists of one or more waves & segments.

Back 48

Interval

Front 49

What are the main differences between the Einthoven & Goldberger methods?

Back 49

Einthoven is bipolar, where as Goldberger is unipolar & provides a stronger signal.

Front 50

If there is no visible Q wave it is called _______.

Back 50

PR interval

Front 51

What is a QRS interval?

Back 51

depolarization of the ventricle
Q=septum, R= rt. & lft ventricle, S= final depolarization of the left ventricle wall

Front 52

What is the ST segment?

Back 52

ventricle remains depolarized (contraction)

Front 53

________ is measured from end of the S wave to the start of the T wave.

Back 53

ST segment

Front 54

______ is the repolarization of the ventricle

Back 54

T wave

Front 55

______ is where depolarization begins & the ECG signal is too small to be recorded.

Back 55

SA Node

Front 56

_____ is recognized by the conduction of the atria & AV node & when depolarization of the AV Node begins.

Back 56

P wave

Front 57

________ represents the AV node & bundle of His on the ECG

Back 57

PQ segment

Front 58

_______ signal is too small to be recorded

Back 58

PQ segment

Front 59

PQ segment = PR segment if ____ wave is missing

Back 59

Q wave

Front 60

______ shows the septum on the ECG & can be missing physiologically

Back 60

Q wave

Front 61

_______ shows the ventricular muscle wall & is normally the strongest signal?

Back 61

R wave

Front 62

_____ shows the ventricular muscle wall, is assymetric & can be missing physiologically.

Back 62

S wave

Front 63

______ signals the the ventricles are continuing to remain depolarized

Back 63

ST segment

Front 64

______ signals the repolarization of the ventricles

Back 64

T wave

Front 65

_______ is the only repolarization signal in the physiological ECG.

Back 65

T wave

Front 66

_______ deflections are measured in time.

Back 66

ECG

Front 67

______ deflections are measured in direction & strength.

Back 67

vectorcardiogram

Front 68

P-wave, QRS interval & T wave each generate _______ in a ECG/vectorcardiogram.

Back 68

one full loop

Front 69

When the heart is in a resting state what signals are shown on the ECG/VCG?

Back 69

no signal recorded
VCG just shows a dot in the center
ECG shows a baseline

Front 70

______ represents the largest loop in the VCG & the largest deflection in the ECG

Back 70

ventricular depolarization

Front 71

______ is shown as a smaller loop than ventricular depolarization in the VCG.

Back 71

ventricular repolarization

Front 72

______ are not represented in the VCG.

Back 72

segments

Front 73

In the ECG where is the value of the electric potential = to zero?

Back 73

Segments PQ,ST,TQ

Front 74

What happens when the value of the vector is zero in a VCG?

Back 74

It is represented as a dot in the intersection point of the leads & can't be measured.